UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2011

Commission file number 1-12672

AVALONBAY COMMUNITIES, INC.

(Exact name of registrant as specified in its charter)

Ballston Tower

671 N. Glebe Rd, Suite 800

Arlington, Virginia 22203

(Address of principal executive office)

(703) 329-6300

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  x    No  ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding twelve (12) months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes  ¨    No  x

The aggregate market value of the registrant’s Common Stock, par value $.01 per share, held by nonaffiliates of the registrant, as of June 30, 2011 was $11,277,881,945.

The number of shares of the registrant’s Common Stock, par value $.01 per share, outstanding as of January 31, 2012 was 95,208,685.

Documents Incorporated by Reference

Portions of AvalonBay Communities, Inc.’s Proxy Statement for the 2012 annual meeting of stockholders, a definitive copy of which will be filed with the SEC within 120 days after the year end of the year covered by this Form 10-K, are incorporated by reference herein as portions of Part III of this Form 10-K.

TABLE OF CONTENTS

PART I

This Form 10-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Our actual results could differ materially from those set forth in each forward-looking statement. Certain factors that might cause such a difference are discussed in this report, including in the section entitled “Forward-Looking Statements” included in this Form 10-K. You should also review Item 1a., “Risk Factors,” for a discussion of various risks that could adversely affect us.

General

AvalonBay Communities, Inc. (the “Company,” which term, unless the context otherwise requires, refers to AvalonBay Communities, Inc. together with its subsidiaries) is a Maryland corporation that has elected to be treated as a real estate investment trust (“REIT”) for federal income tax purposes. We engage in the development, redevelopment, acquisition, ownership and operation of multifamily communities in high barrier to entry markets of the United States. These barriers to entry generally include a difficult and lengthy entitlement process with local jurisdictions and dense urban or suburban areas where zoned and entitled land is in limited supply. Our markets are located in the following regions of the United States: New England, the New York/New Jersey Metro area, the Washington DC Metro area, the Pacific Northwest, Northern and Southern California and currently the Midwest. We focus on these markets because we believe that, over the long-term, a limited new supply of apartment homes and lower housing affordability in these markets will result in higher growth in cash flows relative to other markets.

At January 31, 2012, we owned or held a direct or indirect ownership interest in:

We generally obtain ownership in an apartment community by developing a new community on vacant land or by acquiring an existing community. In selecting sites for development or acquisition, we favor locations that are near expanding employment centers and convenient to transportation, recreation areas, entertainment, shopping and dining.

Our consolidated real estate investments consist of the following reportable segments: Established Communities, Other Stabilized Communities and Development/Redevelopment Communities. Established Communities are generally operating communities that were owned and had stabilized occupancy and operating expenses as of the beginning of the prior year such that year-over-year comparisons are meaningful. Other Stabilized Communities are generally all other operating communities that have stabilized occupancy and operating expenses during the current year, but that were not owned or had not achieved stabilization as of the beginning of the prior year such that year-over-year comparisons are not meaningful, as well as communities that are planned for disposition during the current year. Development/Redevelopment Communities consist of communities that are under construction, communities where substantial redevelopment is in progress or is planned to begin during the current year and communities under lease-up. A more detailed description of these segments and other related information can be found in Note 9, “Segment Reporting,” of the Consolidated Financial Statements set forth in Item 8 of this report.

Our principal financial goal is to increase long-term stockholder value through the development, redevelopment, acquisition, operation, and when appropriate, disposition of apartments in our markets. To help meet this goal, we regularly (i) monitor our investment allocation by geographic market and product type, (ii) develop, redevelop and acquire an interest in apartment communities in high barrier to entry markets with growing or high potential for demand and high for-sale housing costs, (iii) selectively sell apartment communities that no longer meet our long-term strategy or when opportunities are presented to realize a portion of the value created through our investment and redeploy the proceeds from those sales, and (iv) endeavor to maintain a capital structure that is aligned with our business risks with a view to maintaining continuous access to cost-effective capital. Our strategy is to be leaders in multifamily market research, consumer insight, and capital allocation, delivering a range of multifamily offerings

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tailored to serve the needs of the most attractive customer segments in the best-performing U.S. submarkets. A substantial majority of our current communities are upscale, which generally command among the highest rents in their markets. However, we also pursue the ownership and operation of apartment communities that target a variety of customer segments and price points, consistent with our goal of offering a broad range of products and services.

In late 2011, we announced two new apartment community brands that will complement our traditional “Avalon” brand. We believe that this branding segmentation will allow us to better target our product offerings to multiple customer segments and submarkets within our existing geographic footprint. The “Avalon” brand will remain our core offering, focusing on upscale apartment living and high end amenities and services in urban and suburban markets. Our new “AVA” brand is designed for people who want to live in or near urban neighborhoods and in close proximity to public transportation, services, shopping and night-life. AVA apartments will generally be smaller, many engineered for roommate living, and will feature modern design and a technology focus. Our “Eaves by Avalon” brand is designed for renters who seek good quality apartment living, often in a suburban setting, with practical amenities and services at a more modest price point.

During the three years ended December 31, 2011, excluding activity for the Funds (as defined below), we acquired one apartment community. During the same three-year period, excluding dispositions in which we retained an ownership interest, we disposed of 11 apartment communities and completed the development of 19 apartment communities and the redevelopment of 16 apartment communities. In addition, we exchanged a portfolio of three communities and a parcel of land we owned for a portfolio of six communities and $26,000,000 in cash.

During this period, we also realized our pro rata share of the gain from the sale of two communities owned by AvalonBay Value Added Fund, L.P. (“Fund I”), an institutional discretionary real estate investment fund, which we manage and in which we own a 15.2% interest. Fund I acquired communities with the objective of either redeveloping or repositioning them, or taking advantage of market cycle timing and improved operating performance. From its inception in March 2005 through the close of its investment period in March 2008, Fund I acquired 20 communities. Fund I sold one community in 2008, two communities in 2011, and two communities in 2012, through the date this Form 10-K was filed.

In addition, during this period we obtained an investment interest in communities through AvalonBay Value Added Fund II, L.P. (“Fund II”), a second institutional discretionary real estate investment fund which we manage and in which we own a 31.3% interest. While the investment period for Fund II closed in August 2011, additional acquisitions may occur for active acquisition candidates identified prior to the end of the investment period. From the commencement of Fund II through December 31, 2011, Fund II acquired 12 operating communities. In 2012, the Company expects Fund II to acquire its final operating community, which was an active acquisition candidate at the end of the investment period for Fund II. A more detailed description of Fund I and Fund II (collectively, the “Funds”) and the related investment activity can be found in the discussion in Note 6, “Investments in Real Estate Entities,” of the Consolidated Financial Statements in Item 8 of this report.

Excluding the portfolio exchange discussed above, and including sales by unconsolidated entities, during 2011, we sold eight real estate assets, consisting of five operating communities and three land parcels, resulting in a gain in accordance with U.S. generally accepted accounting principles (“GAAP”) of $290,194,000.

A further discussion of our development, redevelopment, disposition, acquisition, property management and related strategies follows.

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Development Strategy. We select land for development and follow established procedures that we believe minimize both the cost and the risks of development. As one of the largest developers of multifamily rental apartment communities in high barrier to entry markets of the United States, we identify development opportunities through local market presence and access to local market information achieved through our regional offices. In addition to our principal executive office in Arlington, Virginia, we also maintain regional offices, administrative offices or specialty offices in or near the following cities:

After selecting a target site, we usually negotiate for the right to acquire the site either through an option or a long-term conditional contract. Options and long-term conditional contracts generally allow us to acquire the target site shortly before the start of construction, which reduces development-related risks and preserves capital. However, as a result of competitive market conditions for land suitable for development, we have sometimes acquired and held land prior to construction for extended periods while entitlements are obtained, or acquired land zoned for uses other than residential with the potential for rezoning. For further discussion of our Development Rights, refer to Item 2. “Communities” in this report.

We generally act as our own general contractor and construction manager, except for certain mid-rise and high-rise apartment communities where we may elect to use third-party general contractors as construction managers. We generally perform these functions directly (although we may use a wholly-owned subsidiary) both for ourselves and for the joint ventures and partnerships of which we are a member or a partner. We believe direct involvement in construction enables us to achieve higher construction quality, greater control over construction schedules and cost savings. Our development, property management and construction teams monitor construction progress to ensure quality workmanship and a smooth and timely transition into the leasing and operating phase.

During periods where competition for development land is more intense, we may acquire improved land with existing commercial uses and rezone the site for multifamily residential use. During the period that we hold these buildings for future development, any net revenue from these operations, which we consider to be incidental, is accounted for as a reduction in our investment in the development pursuit and not as net income. We have also participated, and may in the future participate, in master planned or other large multi-use developments where we commit to build infrastructure (such as roads) to be used by other participants or commit to act as construction manager or general contractor in building structures or spaces for third parties (such as unimproved ground floor retail space, municipal garages or parks). Costs we incur in connection with these activities may be accounted for as additional invested capital in the community or we may earn fee income for providing these services. Particularly with large scale, urban in-fill developments, we may engage in significant environmental remediation efforts to prepare a site for construction.

Throughout this report, the term “development” is used to refer to the entire property development cycle, including pursuit of zoning approvals, procurement of architectural and engineering designs and the construction process. References to “construction” refer to the actual construction of the property, which is only one element of the development cycle.

Redevelopment Strategy. When we undertake the redevelopment of a community, our goal is to renovate and/or rebuild an existing community so that our total investment is generally below replacement cost and the community is well positioned in the market to achieve attractive returns on our capital. We have established a dedicated group of associates and procedures to control both the cost and risks of redevelopment. Our redevelopment teams, which include key redevelopment, construction and property management personnel, monitor redevelopment progress. We believe we achieve significant cost savings by acting as our own general contractor. More importantly, this helps to ensure quality design and workmanship and a smooth and timely transition into the lease-up and restabilization phases.

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Throughout this report, the term “redevelopment” is used to refer to the entire redevelopment cycle, including planning and procurement of architectural and engineering designs, budgeting and actual renovation work. The actual renovation work is referred to as “reconstruction,” which is only one element of the redevelopment cycle.

Disposition Strategy. We sell assets that no longer meet our long-term strategy or when market conditions are favorable, and we redeploy the proceeds from those sales to develop, redevelop and acquire communities and to rebalance our portfolio across or within geographic regions. This also allows us to realize a portion of the value created through our investments and provides additional liquidity. We are then able to redeploy the net proceeds from our dispositions in lieu of raising that amount of capital externally. When we decide to sell a community, we generally solicit competing bids from unrelated parties for these individual assets and consider the sales price of each proposal.

Acquisition Strategy. Our core competencies in development and redevelopment discussed above allow us to be selective in the acquisitions we target. Acquisitions allow us to achieve rapid penetration into markets in which we desire an increased presence. Acquisitions (and dispositions) also help us achieve our desired product mix or rebalance our portfolio. We are not presently pursuing the formation of a new, third fund, preferring at this time to maintain flexibility in shaping our portfolio of wholly-owned assets through acquisitions and dispositions.

Property Management Strategy. We seek to increase operating income through innovative, proactive property management that will result in higher revenue from communities while constraining operating expenses. Our principal strategies to maximize revenue include:

Constraining growth in operating expenses is another way in which we seek to increase earnings growth. Growth in our portfolio and the resulting increase in revenue allows for fixed operating costs to be spread over a larger volume of revenue, thereby increasing operating margins. We constrain growth in operating expenses in a variety of ways, which include, but are not limited to, the following:

On-site property management teams receive bonuses based largely upon the net operating income (“NOI”) produced at their respective communities. We use and continuously seek ways to improve technology applications to help manage our communities, believing that the accurate collection of financial and resident data will enable us to maximize revenue and control costs through careful leasing decisions, maintenance decisions and financial management.

We generally manage the operation and leasing activity of our communities directly (although we may use a wholly-owned subsidiary) both for ourselves and the joint ventures and partnerships of which we are a member or a partner.

From time to time we also pursue or arrange ancillary services for our residents to provide additional revenue sources or increase resident satisfaction. As a REIT, we generally cannot provide direct services to our tenants that are not customarily provided by a landlord, nor can we directly share in the income of a third party that provides such services. However, we can provide such non-customary services to residents or share in the revenue from such services if we do so through a “taxable REIT subsidiary,” which is a subsidiary that is treated as a “C corporation” subject to federal income taxes.

Financing Strategy. We maintain a capital structure that provides financial flexibility to ensure we can select cost effective capital market options that are well matched to our business risks. We estimate that our short-term liquidity needs will be met from cash on hand, borrowings under our $750,000,000 revolving variable rate unsecured credit facility (the “Credit Facility”), sales of current operating communities and/or issuance of additional debt or equity securities. A determination to engage in an equity or debt offering depends on a variety of factors such as general

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market and economic conditions, our short and long-term liquidity needs, the relative costs of debt and equity capital and growth opportunities. A summary of debt and equity activity for the last three years is reflected on our Consolidated Statement of Cash Flows of the Consolidated Financial Statements set forth in Item 8 of this report.

We have entered into, and may continue in the future to enter into, joint ventures (including limited liability companies or partnerships) through which we would own an indirect economic interest of less than 100% of the community or communities owned directly by such joint ventures. Our decision to either hold an apartment community in fee simple or to have an indirect interest in the community through a joint venture is based on a variety of factors and considerations, including: (i) the economic and tax terms required by a seller of land or of a community; (ii) our desire to diversify our portfolio of communities by market, submarket and product type; (iii) our desire at times to preserve our capital resources to maintain liquidity or balance sheet strength; and (iv) our projection, in some circumstances, that we will achieve higher returns on our invested capital or reduce our risk if a joint venture vehicle is used. Investments in joint ventures are not limited to a specified percentage of our assets. Each joint venture agreement is individually negotiated, and our ability to operate and/or dispose of a community in our sole discretion may be limited to varying degrees depending on the terms of the joint venture agreement.

In addition, from time to time, we may offer shares of our equity securities, debt securities or options to purchase stock in exchange for property. We may also acquire properties in exchange for properties we currently own.

Other Strategies and Activities. While we emphasize equity real estate investments in rental apartment communities, we have the ability to invest in other types of real estate, mortgages (including participating or convertible mortgages), securities of other REITs or real estate operating companies, or securities of technology companies that relate to our real estate operations or of companies that provide services to us or our residents, in each case consistent with our qualification as a REIT. In addition, we own and lease retail space at our communities when either (i) the highest and best use of the space is for retail (e.g., street level in an urban area); (ii) we believe the retail space will enhance the attractiveness of the community to residents or; (iii) some component of retail space is required to obtain entitlements to build apartment homes. As of December 31, 2011, we had a total of 530,604 square feet of rentable retail space, excluding retail space within communities currently under construction. Gross rental revenue provided by leased retail space in 2011 was $8,131,000 (0.8% of total revenue). We may also develop a property in conjunction with another real estate company that will own and operate the retail component of a mixed-use building that we help develop. If we secure a development right and believe that its best use, in whole or in part, is to develop the real estate with the intent to sell rather than hold the asset, we may, through a taxable REIT subsidiary, develop real estate for sale. Any investment in securities of other entities, and any development of real estate for sale, is subject to the percentage of ownership limitations, gross income tests, and other limitations that must be observed for REIT qualification.

We have not engaged in trading, underwriting or agency distribution or sale of securities of other issuers and do not intend to do so. At all times we intend to make investments in a manner so as to qualify as a REIT unless, because of circumstances or changes to the Internal Revenue Code of 1986 (or the Treasury Regulations), our Board of Directors determines that it is no longer in our best interest to qualify as a REIT.

Tax Matters

We filed an election with our 1994 federal income tax return to be taxed as a REIT under the Internal Revenue Code of 1986, as amended, (“the Code”) and intend to maintain our qualification as a REIT in the future. As a qualified REIT, with limited exceptions, we will not be taxed under federal and certain state income tax laws at the corporate level on our taxable net income to the extent taxable net income is distributed to our stockholders. We expect to make sufficient distributions to avoid income tax at the corporate level. While we believe that we are organized and qualified as a REIT and we intend to operate in a manner that will allow us to continue to qualify as a REIT, there can be no assurance that we will be successful in this regard. Qualification as a REIT involves the application of highly technical and complex provisions of the Code for which there are limited judicial and administrative interpretations and involves the determination of a variety of factual matters and circumstances not entirely within our control.

Competition

We face competition from other real estate investors, including insurance companies, pension and investment funds, partnerships and investment companies and other REITs, to acquire and develop apartment communities and acquire land for future development. As an owner and operator of apartment communities, we also face competition for prospective residents from other operators whose communities may be perceived to offer a better location or better amenities or whose rent may be perceived as a better value given the quality, location and amenities that the resident seeks. We also compete against condominiums and single-family homes that are for sale or rent. Although we often compete against large sophisticated developers and operators for development opportunities and for prospective residents, real estate developers and operators of any size can provide effective competition for both real estate assets and potential residents.

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Environmental and Related Matters

As a current or prior owner, operator and developer of real estate, we are subject to various federal, state and local environmental laws, regulations and ordinances and also could be liable to third parties resulting from environmental contamination or noncompliance at our communities. For some development communities, we undertake extensive environmental remediation to prepare the site for construction, which could be a significant portion of our total construction cost. Environmental remediation efforts could expose us to possible liabilities for accidents or improper handling of contaminated materials during construction. These and other risks related to environmental matters are described in more detail in Item 1a., “Risk Factors.”

We believe that more government regulation of energy use, along with a greater focus on environmental protection may, over time, have a significant impact on urban growth patterns. If changes in zoning to encourage greater density and proximity to mass transit do occur, such changes could benefit multifamily housing and those companies with a competency in high-density development. However, there can be no assurance as to whether or when such changes in regulations or zoning will occur or, if they do occur, whether the multifamily industry or the Company will benefit from such changes.

Other Information

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. You may call the SEC at 1-202-551-8090 for further information on the operation of the Public Reference Room. Our SEC filings are also available to the public from the SEC’s website at www.sec.gov.

We maintain a website at www.avalonbay.com. Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports, filed or furnished pursuant to the Securities Exchange Act of 1934 are available free of charge in the “Investors” section of our website as soon as reasonably practicable after the reports are filed with or furnished to the SEC. In addition, the charters of our Board’s Nominating and Corporate Governance Committee, Audit Committee and Compensation Committee, as well as our Director Independence Standards, Corporate Governance Guidelines, Policy Regarding Shareholder Rights Agreement and Code of Conduct, are available free of charge in that section of our website or by writing to AvalonBay Communities, Inc., Ballston Tower, Suite 800, 671 N. Glebe Rd., Arlington, Virginia 22203, Attention: Chief Financial Officer. To the extent required by the rules of the SEC and the NYSE, we will disclose amendments and waivers relating to these documents in the same place on our website.

We were incorporated under the laws of the State of California in 1978. In 1995, we reincorporated in the State of Maryland and have been focused on the ownership and operation of apartment communities since that time. As of January 31, 2012, we had 2,095 employees.

Our operations involve various risks that could have adverse consequences, including those described below. This Item 1a. includes forward-looking statements. You should refer to our discussion of the qualifications and limitations on forward-looking statements in this Form 10-K.

Development, redevelopment and construction risks could affect our profitability.

We intend to continue to develop and redevelop apartment home communities. These activities can include long planning and entitlement timelines and can involve complex and costly activities, including significant environmental remediation or construction work in high-density urban areas. These activities may be exposed to the following risks:

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We estimate construction costs based on market conditions at the time we prepare our budgets, and our projections include changes that we anticipate but cannot predict with certainty. Construction costs may increase, particularly for labor and certain materials and, for some of our Development Communities and Development Rights (as defined below), the total construction costs may be higher than the original budget. Total capitalized cost includes all capitalized costs incurred and projected to be incurred to develop or redevelop a community, determined in accordance with GAAP, including:

Costs to redevelop communities that have been acquired have, in some cases, exceeded our original estimates and similar increases in costs may be experienced in the future. We cannot assure you that market rents in effect at the time new development or redevelopment communities complete lease-up will be sufficient to fully offset the effects of any increased construction or reconstruction costs.

Unfavorable changes in market and economic conditions could adversely affect occupancy, rental rates, operating expenses, and the overall market value of our assets, including joint ventures and investments in the Funds.

Local conditions in our markets significantly affect occupancy, rental rates and the operating performance of our communities. The risks that may adversely affect conditions in those markets include the following:

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Changes in applicable laws, or noncompliance with applicable laws, could adversely affect our operations or expose us to liability.

We must develop, construct and operate our communities in compliance with numerous federal, state and local laws and regulations, some of which may conflict with one another or be subject to limited judicial or regulatory interpretations. These laws and regulations may include zoning laws, building codes, landlord tenant laws and other laws generally applicable to business operations. Noncompliance with laws could expose us to liability.

Lower revenue growth or significant unanticipated expenditures may result from our need to comply with changes in (i) laws imposing remediation requirements and the potential liability for environmental conditions existing on properties or the restrictions on discharges or other conditions, (ii) rent control or rent stabilization laws or other residential landlord/tenant laws, or (iii) other governmental rules and regulations or enforcement policies affecting the development, use and operation of our communities, including changes to building codes and fire and life-safety codes.

Short-term leases expose us to the effects of declining market rents.

Substantially all of our apartment leases are for a term of one year or less. Because these leases generally permit the residents to leave at the end of the lease term without penalty, our rental revenues are impacted by declines in market rents more quickly than if our leases were for longer terms.

Competition could limit our ability to lease apartment homes or increase or maintain rents.

Our apartment communities compete with other housing alternatives to attract residents, including other rental apartments, condominiums and single-family homes that are available for rent, as well as new and existing condominiums and single-family homes for sale. Competitive residential housing in a particular area could adversely affect our ability to lease apartment homes and to increase or maintain rental rates.

Attractive investment opportunities may not be available, which could adversely affect our profitability.

We expect that other real estate investors, including insurance companies, pension funds, other REITs and other well-capitalized investors, will compete with us to acquire existing properties and to develop new properties. This competition could increase prices for properties of the type we would likely pursue and adversely affect our profitability.

Capital and credit market conditions may adversely affect our access to various sources of capital and/or the cost of capital, which could impact our business activities, dividends, earnings, and common stock price, among other things.

In periods when the capital and credit markets experience significant volatility, the amounts, sources and cost of capital available to us may be adversely affected. We primarily use external financing to fund construction and to refinance indebtedness as it matures. If sufficient sources of external financing are not available to us on cost effective terms, we could be forced to limit our development and redevelopment activity and/or take other actions to fund our business activities and repayment of debt, such as selling assets, reducing our cash dividend or paying out less than 100% of our taxable income. To the extent that we are able and/or choose to access capital at a higher cost than we have experienced in recent years (reflected in higher interest rates for debt financing or a lower stock price for equity financing) our earnings per share and cash flows could be adversely affected. In addition, the price of our common stock may fluctuate significantly and/or decline in a high interest rate or volatile economic environment. We believe that the lenders under our Credit Facility will fulfill their lending obligations thereunder, but if economic conditions deteriorate, there can be no assurance that the ability of those lenders to fulfill their obligations would not be adversely impacted.

Insufficient cash flow could affect our debt financing and create refinancing risk.

We are subject to the risks associated with debt financing, including the risk that our cash flow will be insufficient to meet required payments of principal and interest. In this regard, we note that in order for us to continue to qualify as a REIT, we are required to annually distribute dividends generally equal to at least 90% of our REIT taxable income, computed without regard to the dividends paid deduction and our net capital gain. This requirement limits the amount of our cash flow available to meet required principal and interest payments. The principal outstanding balance on a portion of our debt will not be fully amortized prior to its maturity. Although we may be able to repay our debt by using our cash flows, we cannot assure you that we will have sufficient cash flows available to make all required principal payments. Therefore, we may need to refinance at least a portion of our outstanding debt as it matures. There is a risk that we may not be able to refinance existing debt or that a refinancing will not be done on as favorable terms; either of these outcomes could have a material adverse effect on our financial condition and results of operations.

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Rising interest rates could increase interest costs and could affect the market price of our common stock.

We currently have, and may in the future incur, contractual variable interest rate debt, as well as effective variable interest rate debt achieved through the use of qualifying hedging relationships. In addition, we regularly seek access to both fixed and variable rate debt financing to repay maturing debt and to finance our development and redevelopment activity. Accordingly, if interest rates increase, our interest costs will also rise, unless we have made arrangements that hedge the risk of rising interest rates. In addition, an increase in market interest rates may lead purchasers of our common stock to demand a greater annual dividend yield, which could adversely affect the market price of our common stock.

Bond financing and zoning compliance requirements could limit our income, restrict the use of communities and cause favorable financing to become unavailable.

We have financed some of our apartment communities with obligations issued by local government agencies because the interest paid to the holders of this debt is generally exempt from federal income taxes and, therefore, the interest rate is generally more favorable to us. These obligations are commonly referred to as “tax-exempt bonds” and generally must be secured by mortgages on our communities. As a condition to obtaining tax-exempt financing, or on occasion as a condition to obtaining favorable zoning in some jurisdictions, we will commit to make some of the apartments in a community available to households whose income does not exceed certain thresholds (e.g., 50% or 80% of area median income), or who meet other qualifying tests. As of December 31, 2011, approximately 6.11% of our apartment homes at current operating communities were under income limitations such as these. These commitments, which may run without expiration or may expire after a period of time (such as 15 or 20 years) may limit our ability to raise rents and, in consequence, can also adversely affect the value of the communities subject to these restrictions.

In addition, some of our tax-exempt bond financing documents require us to obtain a guarantee from a financial institution of payment of the principal of, and interest on, the bonds. The guarantee may take the form of a letter of credit, surety bond, guarantee agreement or other additional collateral. If the financial institution defaults in its guarantee obligations, or if we are unable to renew the applicable guarantee or otherwise post satisfactory collateral, a default will occur under the applicable tax-exempt bonds and the community could be foreclosed upon if we do not redeem the bonds.

Risks related to indebtedness.

We have a Credit Facility with Bank of America, N.A., as administrative agent, swing lender, issuing bank and a bank, JPMorgan Chase Bank, N.A., as a bank and as syndication agent, Deutsche Bank Trust Company Americas, Morgan Stanley Bank and Wells Fargo Bank, N.A., each as a bank and as documentation agent, Barclays Bank PLC as a bank and as co-documentation agent, UBS Securities LLC as a co-documentation agent, The Bank of New York Mellon, BBVA Compass Bank, PNC Bank, National Association, and Suntrust Bank, each as a bank and as a managing agent, Branch Banking and Trust Company, Bank of Tokyo Mitsubishi UFJ, Ltd., and Citizens Bank, each as a bank and as a co-agent, and the other bank parties signatory thereto. Our organizational documents do not limit the amount or percentage of indebtedness that may be incurred. Accordingly, subject to compliance with outstanding debt covenants, we could incur more debt, resulting in an increased risk of default on our obligations and an increase in debt service requirements that could adversely affect our financial condition and results of operations.

The mortgages on those of our properties subject to secured debt, our Credit Facility and the indenture under which a substantial portion of our debt was issued contain customary restrictions, requirements and other limitations, as well as certain financial and operating covenants including maintenance of certain financial ratios. Maintaining compliance with these restrictions could limit our flexibility. A default in these requirements, if uncured, could result in a requirement that we repay indebtedness, which could severely affect our liquidity and increase our financing costs. Refer to Item 7., “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” for further discussion.

The mortgages on those of our properties subject to secured debt generally include provisions which stipulate a prepayment penalty or payment that we will be obligated to pay in the event that we elect to repay the mortgage note prior to the earlier of (i) the stated maturity of the note, or (ii) the date at which the mortgage note is prepayable without such penalty or payment. If we elect to repay some or all of the outstanding principal balance for our mortgage notes, we may incur prepayment penalties or payments under these provisions which could adversely affect our results of operations.

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Failure to maintain our current credit ratings could adversely affect our cost of funds, related margins, liquidity and access to capital markets.

There are two major debt rating agencies that routinely evaluate and rate our debt. These ratings are based on a number of factors, which include their assessment of our financial strength, liquidity, capital structure, asset quality amount of real estate under development, and sustainability of cash flow and earnings, among other factors. If market conditions change, we may not be able to maintain our current credit ratings, which could adversely affect our cost of funds and related margins, liquidity, and access to capital markets.

We could be negatively impacted by the condition of Fannie Mae or Freddie Mac.

Fannie Mae and Freddie Mac are a major source of secured financing to the multifamily industry and we have used Fannie Mae and Freddie Mac for a portion of our financing needs. In February 2011, the Obama administration released a report calling for the winding down of the role that Fannie Mae and Freddie Mac play in the mortgage market. A final decision by the government to eliminate Fannie Mae or Freddie Mac or reduce their acquisitions or guarantees of multifamily community loans may adversely affect interest rates, capital availability, and the value of multifamily communities.

Failure to generate sufficient revenue or other liquidity needs could limit cash flow available for distributions to stockholders.

A decrease in rental revenue or other liquidity needs, including the repayment of indebtedness or funding of our development activities, could have an adverse effect on our ability to pay distributions to our stockholders. Significant expenditures associated with each community such as debt service payments, if any, real estate taxes, insurance and maintenance costs are generally not reduced when circumstances cause a reduction in income from a community.

The form, timing and/or amount of dividend distributions in future periods may vary and be impacted by economic and other considerations.

The form, timing and/or amount of dividend distributions will be declared at the discretion of the Board of Directors and will depend on actual cash from operations, our financial condition, capital requirements, the annual distribution requirements under the REIT provisions of the Code and other factors as the Board of Directors may consider relevant. The Board of Directors may modify our dividend policy from time to time.

We may choose to pay dividends in our own stock, in which case stockholders may be required to pay tax in excess of the cash they receive.

We may distribute taxable dividends that are payable in part in our stock, as we did in the fourth quarter of 2008. Taxable stockholders receiving such dividends will be required to include the full amount of the dividend as income to the extent of our current and accumulated earnings and profits for federal income tax purposes. As a result, a U.S. stockholder may be required to pay tax with respect to such dividends in excess of the cash received. If a U.S. stockholder sells the stock it receives as a dividend in order to pay this tax, the sales proceeds may be less than the amount included in income with respect to the dividend, depending on the market price of our stock at the time of the sale. Furthermore, with respect to non-U.S. stockholders, we may be required to withhold U.S. tax with respect to such dividends, including in respect of all or a portion of such dividend that is payable in stock. In addition, the trading price of our stock would experience downward pressure if a significant number of our stockholders sell shares of our stock in order to pay taxes owed on dividends.

Debt financing may not be available and equity issuances could be dilutive to our stockholders.

Our ability to execute our business strategy depends on our access to an appropriate blend of debt and equity financing. Debt financing may not be available in sufficient amounts or on favorable terms. If we issue additional equity securities, the interests of existing stockholders could be diluted.

Difficulty of selling apartment communities could limit flexibility.

Federal tax laws may limit our ability to earn a gain on the sale of a community (unless we own it through a subsidiary which will incur a taxable gain upon sale) if we are found to have held, acquired or developed the community primarily with the intent to resell the community, and this limitation may affect our ability to sell communities without adversely affecting returns to our stockholders. In addition, real estate in our markets can at times be difficult to sell quickly at prices we find acceptable. These potential difficulties in selling real estate in our markets may limit our ability to change or reduce the apartment communities in our portfolio promptly in response to changes in economic or other conditions.

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Acquisitions may not yield anticipated results.

Our business strategy includes acquiring as well as developing communities. Our acquisition activities and their success may be exposed to the following risks:

Failure to succeed in new markets, or with new brands and community formats, or in activities other than the development, ownership and operation of residential rental communities may have adverse consequences.

We may from time to time commence development activity or make acquisitions outside of our existing market areas if appropriate opportunities arise. Our historical experience in our existing markets in developing, owning and operating rental communities does not ensure that we will be able to operate successfully in new markets, should we choose to enter them. We may be exposed to a variety of risks if we choose to enter new markets, including an inability to accurately evaluate local apartment market conditions; an inability to obtain land for development or to identify appropriate acquisition opportunities; an inability to hire and retain key personnel; and lack of familiarity with local governmental and permitting procedures.

Although we are primarily in the multifamily business, we also own and lease ancillary retail space when a retail component represents the best use of the space, as is often the case with large urban in-fill developments. We also may engage or have an interest in for-sale activity. We may be unsuccessful in owning and leasing retail space at our communities or in developing real estate with the intent to sell, which could have an adverse effect on our results of operations.

We are currently implementing two new brands of communities that target various customer preferences. We cannot assure that these brands will be successful or that our costs in developing and implementing these brands will result in incremental revenue and earnings.

Land we hold with no current intent to develop may be subject to future impairment charges.

We own parcels of land that we do not currently intend to develop. As discussed in Item 2., “Communities – Other Land and Real Estate Assets,” in the event that the fair market value of a parcel changes such that we determine that the carrying basis of the parcel reflected in our financial statements is greater than the parcel’s then current fair value, less costs to dispose, we would be subject to an impairment charge, which would reduce our net income.

Risks involved in real estate activity through joint ventures.

Instead of acquiring or developing apartment communities directly, at times we invest as a partner or a co-venturer. Joint venture investments (including investments through partnerships or limited liability companies) involve risks, including the possibility that our partner might become insolvent or otherwise refuse to make capital contributions when due; that we may be responsible to our partner for indemnifiable losses; that our partner might at any time have business goals which are inconsistent with ours; and that our partner may be in a position to take action or withhold consent contrary to our instructions or requests. Frequently, we and our partner may each have the right to trigger a buy-sell arrangement, which could cause us to sell our interest, or acquire our partner’s interest, at a time when we otherwise would not have initiated such a transaction.

Risks associated with an investment in and management of discretionary real estate investment funds.

We formed Fund I and Fund II, in which we have an equity interest of 15.2% and 31.3%, respectively, which, through wholly-owned subsidiaries, we manage as the general partner and in which we have invested an aggregate of approximately $146,465,000, net of distributions to us at December 31, 2011. The investment period for both Funds is over. These Funds present risks, including the following:

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Risk of earthquake damage.

As further described in Item 2., “Communities – Insurance and Risk of Uninsured Losses,” many of our West Coast communities are located in the general vicinity of active earthquake faults. We cannot assure you that an earthquake would not cause damage or losses greater than insured levels. In the event of a loss in excess of insured limits, we could lose our capital invested in the affected community, as well as anticipated future revenue from that community. We would also continue to be obligated to repay any mortgage indebtedness or other obligations related to the community. Any such loss could materially and adversely affect our business and our financial condition and results of operations.

Insurance coverage for earthquakes can be costly due to limited industry capacity. As a result, we may experience shortages in desired coverage levels if market conditions are such that insurance is not available or the cost of insurance makes it, in management’s view, economically impractical.

A significant uninsured property or liability loss could have a material adverse effect on our financial condition and results of operations.

In addition to the earthquake insurance discussed above, we carry commercial general liability insurance, property insurance and terrorism insurance with respect to our communities on terms we consider commercially reasonable. There are, however, certain types of losses (such as losses arising from acts of war) that are not insured, in full or in part, because they are either uninsurable or the cost of insurance makes it, in management’s view, economically impractical. If an uninsured property loss or a property loss in excess of insured limits were to occur, we could lose our capital invested in a community, as well as the anticipated future revenues from such community. We would also continue to be obligated to repay any mortgage indebtedness or other obligations related to the community. If an uninsured liability to a third party were to occur, we would incur the cost of defense and settlement with, or court ordered damages to, that third party. A significant uninsured property or liability loss could materially and adversely affect our business and our financial condition and results of operations.

We may incur costs and increased expenses to repair property damage resulting from inclement weather.

Particularly in New England, the New York and New Jersey Metro area and the Midwest, we are exposed to risks associated with inclement winter weather, including increased costs for the removal of snow and ice as well as from delays in construction. In addition, inclement weather could increase the need for maintenance and repair of our communities.

We may incur costs due to environmental contamination or non-compliance.

Under various federal, state and local environmental and public health laws, regulations and ordinances, we may be required, regardless of knowledge or responsibility, to investigate and remediate the effects of hazardous or toxic substances or petroleum product releases at our properties (including in some cases natural substances such as methane and radon gas) and may be held liable under these laws or common law to a governmental entity or to third parties for property, personal injury or natural resources damages and for investigation and remediation costs incurred as a result of the contamination. These damages and costs may be substantial and may exceed any insurance coverage we have for such events. The presence of such substances, or the failure to properly remediate the contamination, may adversely affect our ability to borrow against, sell or rent the affected property.

In addition, some environmental laws create or allow a government agency to impose a lien on the contaminated site in favor of the government for damages and costs it incurs as a result of the contamination.

The development, construction and operation of our communities are subject to regulations and permitting under various federal, state and local laws, regulations and ordinances, which regulate matters including wetlands protection, storm water runoff and wastewater discharge. Noncompliance with such laws and regulations may subject us to fines and penalties. We do not currently anticipate that we will incur any material liabilities as a result of noncompliance with these laws.

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Certain federal, state and local laws, regulations and ordinances govern the removal, encapsulation or disturbance of asbestos containing materials (“ACMs”) when such materials are in poor condition or in the event of renovation or demolition of a building. These laws and the common law may impose liability for release of ACMs and may allow third parties to seek recovery from owners or operators of real properties for personal injury associated with exposure to ACMs. We are not aware that any ACMs were used in the construction of the communities we developed. ACMs were, however, used in the construction of a number of the communities that we acquired. We implement an operations and maintenance program at each of the communities at which ACMs are detected. We do not currently anticipate that we will incur any material liabilities as a result of the presence of ACMs at our communities.

We are aware that some of our communities have lead paint and have implemented an operations and maintenance program at each of those communities. We do not currently anticipate that we will incur any material liabilities as a result of the presence of lead paint at our communities.

We are also aware that environmental agencies and third parties have, in the case of certain properties with on-site or nearby contamination, asserted claims for remediation or personal injury based on the alleged actual or potential intrusion into buildings of chemical vapors from soils or groundwater underlying or in the vicinity of those buildings or on nearby properties. We currently do not anticipate that we will incur any material liabilities as a result of vapor intrusion at our communities.

All of our stabilized operating communities, and all of the communities that we are currently developing, have been subjected to at least a Phase I or similar environmental assessment, which generally does not involve invasive techniques such as soil or ground water sampling. These assessments, together with subsurface assessments conducted on some properties, have not revealed, and we are not otherwise aware of, any environmental conditions that we believe would have a material adverse effect on our business, assets, financial condition or results of operations. In connection with our ownership, operation and development of communities, from time to time we undertake substantial remedial action in response to the presence of subsurface or other contaminants, including contaminants in soil, groundwater and soil vapor beneath or affecting our buildings. In some cases, an indemnity exists upon which we may be able to rely if environmental liability arises from the contamination or remediation costs exceed estimates. There can be no assurance, however, that all necessary remediation actions have been or will be undertaken at our properties or that we will be indemnified, in full or at all, in the event that environmental liability arises.

Mold growth may occur when excessive moisture accumulates in buildings or on building materials, particularly if the moisture problem remains undiscovered or is not addressed over a period of time. Although the occurrence of mold at multifamily and other structures, and the need to remediate such mold, is not a new phenomenon, there has been increased awareness in recent years that certain molds may in some instances lead to adverse health effects, including allergic or other reactions. To help limit mold growth, we educate residents about the importance of adequate ventilation and request or require that they notify us when they see mold or excessive moisture. We have established procedures for promptly addressing and remediating mold or excessive moisture from apartment homes when we become aware of its presence regardless of whether we or the resident believe a health risk is presented. However, we cannot provide assurance that mold or excessive moisture will be detected and remediated in a timely manner. If a significant mold problem arises at one of our communities, we could be required to undertake a costly remediation program to contain or remove the mold from the affected community and could be exposed to other liabilities that may exceed any applicable insurance coverage.

Additionally, we have occasionally been involved in developing, managing, leasing and operating various properties for third parties. Consequently, we may be considered to have been an operator of such properties and, therefore, potentially liable for removal or remediation costs or other potential costs which relate to the release or presence of hazardous or toxic substances. We are not aware of any material environmental liabilities with respect to properties managed or developed by us or our predecessors for such third parties.

We cannot assure you that:

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Our success depends on key personnel whose continued service is not guaranteed.

Our success depends in part on our ability to attract and retain the services of executive officers and other personnel. Our executive officers make important capital allocation decisions or recommendations to our Board of Directors from among the opportunities identified by our regional offices. There is substantial competition for qualified personnel in the real estate industry, and the loss of several of our key personnel could adversely affect the Company.

Breaches of our data security could materially harm our business and reputation.

We collect and retain certain personal information provided by our tenants and employees. While we have implemented a variety of security measures to protect the confidentiality of this information and periodically review and improve our security measures, there can be no assurance that we will be able to prevent unauthorized access to this information. Any breach of our data security measures and loss of this information may result in legal liability and costs (including damages and penalties), as well as damage to our reputation, that could materially and adversely affect our business and financial performance.

Failure to qualify as a REIT would cause us to be taxed as a corporation, which would significantly reduce funds available for distribution to stockholders.

If we fail to qualify as a REIT for federal income tax purposes, we will be subject to federal income tax on our taxable income at regular corporate rates (subject to any applicable alternative minimum tax). In addition, unless we are entitled to relief under applicable statutory provisions, we would be ineligible to make an election for treatment as a REIT for the four taxable years following the year in which we lose our qualification. The additional tax liability resulting from the failure to qualify as a REIT would significantly reduce or eliminate the amount of funds available for distribution to our stockholders. Furthermore, we would no longer be required to make distributions to our stockholders. Thus, our failure to qualify as a REIT could also impair our ability to expand our business and raise capital, and would adversely affect the value of our common stock.

We believe that we are organized and qualified as a REIT, and we intend to operate in a manner that will allow us to continue to qualify as a REIT. However, we cannot assure you that we are qualified as a REIT, or that we will remain qualified in the future. This is because qualification as a REIT involves the application of highly technical and complex provisions of the Internal Revenue Code for which there are only limited judicial and administrative interpretations and involves the determination of a variety of factual matters and circumstances not entirely within our control. In addition, future legislation, new regulations, administrative interpretations or court decisions may significantly change the tax laws or the application of the tax laws with respect to qualification as a REIT for federal income tax purposes or the federal income tax consequences of this qualification.

Even if we qualify as a REIT, we will be subject to certain federal, state and local taxes on our income and property and on taxable income that we do not distribute to our shareholders. In addition, we may engage in activities that are not customarily provided by a landlord through taxable subsidiaries and will be subject to federal income tax at regular corporate rates on the income of those subsidiaries.

The ability of our stockholders to control our policies and effect a change of control of our company is limited by certain provisions of our charter and bylaws and by Maryland law.

There are provisions in our charter and bylaws that may discourage a third party from making a proposal to acquire us, even if some of our stockholders might consider the proposal to be in their best interests. These provisions include the following:

Our charter authorizes our Board of Directors to issue up to 50,000,000 shares of preferred stock without stockholder approval and to establish the preferences and rights, including voting rights, of any series of preferred stock issued. The Board of Directors may issue preferred stock without stockholder approval, which could allow the Board to issue one or more classes or series of preferred stock that could discourage or delay a tender offer or a change in control.

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To maintain our qualification as a REIT for federal income tax purposes, not more than 50% in value of our outstanding stock may be owned, directly or indirectly, by or for five or fewer individuals at any time during the last half of any taxable year. To maintain this qualification, and/or to address other concerns about concentrations of ownership of our stock, our charter generally prohibits ownership (directly, indirectly by virtue of the attribution provisions of the Code, or beneficially as defined in Section 13 of the Securities Exchange Act) by any single stockholder of more than 9.8% of the issued and outstanding shares of any class or series of our stock. In general, under our charter, pension plans and mutual funds may directly and beneficially own up to 15% of the outstanding shares of any class or series of stock. Under our charter, our Board of Directors may in its sole discretion waive or modify the ownership limit for one or more persons, but is not required to do so even if such waiver would not affect our qualification as a REIT. These ownership limits may prevent or delay a change in control and, as a result, could adversely affect our stockholders’ ability to realize a premium for their shares of common stock.

Our bylaws provide that the affirmative vote of holders of a majority of all of the shares entitled to be cast in the election of directors is required to elect a director. In a contested election, if no nominee receives the vote of holders of a majority of all of the shares entitled to be cast, the incumbent directors would remain in office. This requirement may prevent or delay a change in control and, as a result, could adversely affect our stockholders’ ability to realize a premium for their shares of common stock.

As a Maryland corporation, we are subject to the provisions of the Maryland General Corporation Law. Maryland law imposes restrictions on some business combinations and requires compliance with statutory procedures before some mergers and acquisitions may occur, which may delay or prevent offers to acquire us or increase the difficulty of completing any offers, even if they are in our stockholders’ best interests. In addition, other provisions of the Maryland General Corporation Law permit the Board of Directors to make elections and to take actions without stockholder approval (such as classifying our Board such that the entire Board is not up for reelection annually) that, if made or taken, could have the effect of discouraging or delaying a change in control.

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None.

Our real estate investments consist primarily of current operating apartment communities, communities in various stages of development (“Development Communities”) and Development Rights (as defined below). Our current operating communities are further distinguished as Established Communities, Other Stabilized Communities, Lease-Up Communities and Redevelopment Communities. The following is a description of each category:

Current Communities are categorized as Established, Other Stabilized, Lease-Up, or Redevelopment according to the following attributes:

Development Communities are communities that are under construction and for which a certificate of occupancy has not been received for the entire community. These communities may be partially complete and operating.

Development Rights are development opportunities in the early phase of the development process for which we either have an option to acquire land or enter into a leasehold interest, for which we are the buyer under a long-term conditional contract to purchase land or where we own land to develop a new community. We capitalize related pre-development costs incurred in pursuit of new developments for which we currently believe future development is probable.

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As of December 31, 2011, communities that we owned or held a direct or indirect interest in were classified as follows:

Our holdings under each of the above categories are discussed on the following pages.

Current Communities

Our Current Communities include garden-style apartment communities consisting of multi-story buildings in landscaped settings, as well as mid and high rise apartment communities in urban settings. As of January 31, 2012, our current communities consisted of 126 garden-style (of which 16 are mixed communities and/or include town homes), 22 high-rise and 32 mid-rise apartment communities.

Our communities generally offer a variety of quality amenities and features, which may include:

Other features at various communities may include:

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As described in Item 1, in late 2011 we announced the introduction of two new brands to supplement our core Avalon offering, which remains focused on upscale apartment living and high end amenities and services. “AVA” will target customers in high energy, transit-served urban neighborhoods and will feature smaller apartments, many of which are designed for roommate living with an emphasis on modern design and a technology focus. “Eaves by Avalon” is targeted to the cost conscious, “value” segment and will likely be concentrated in older assets in suburban areas. We believe that the addition of these new brands will allow us to further penetrate our existing markets, by segmenting our market by consumer preference and attitude as well as by location and price.

We also have an extensive and ongoing maintenance program to continually maintain and enhance our communities and apartment homes. The aesthetic appeal of our communities and a service-oriented property management team, focused on the specific needs of residents, enhances market appeal to discriminating residents. We believe our mission of Enhancing the Lives of our Residents helps us achieve higher rental rates and occupancy levels while minimizing resident turnover and operating expenses.

Our Current Communities are located in the following geographic markets:

We manage and operate substantially all of our Current Communities. During the year ended December 31, 2011, we completed construction of 1,161 apartment homes in six communities, sold 1,313 apartment homes in five communities, and exchanged three communities with 1,060 apartment homes for six communities with 1,418 apartment homes with another apartment owner. The average age of our Current Communities, on a weighted average basis according to number of apartment homes, is 17 years. When adjusted to reflect redevelopment activity, as if redevelopment were a new construction completion date, the average age of our Current Communities is 11 years.

Of the Current Communities, as of January 31, 2012, we owned:

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For some communities, a land lease is used to support tax advantaged structures that ultimately allow us to purchase the land upon lease expiration. We have options to purchase the underlying land for the leases that expire in October 2026, November 2028, December 2034 and April 2095. We also hold, directly or through wholly-owned subsidiaries, the full fee simple ownership interest in 16 of the 19 Development Communities and a leasehold interest in three of the Development Communities with the land leases expiring in July 2046, November 2106, and May 2041. Two of the three land leases (those expiring in 2041 and 2046) provide options for the Company to purchase the land at some point during the lease term.

In our partnership structured as a DownREIT, one of our wholly-owned subsidiaries is the general partner, and there are one or more limited partners whose interest in the partnership is represented by units of limited partnership interest. Limited partners are entitled to receive an initial distribution before any distribution is made to the general partner. Under the partnership agreement for the DownREIT, the distributions per unit paid to the holders of units of limited partnership interests are equal to our current common stock dividend amount. The holders of units of limited partnership interest have the right to present all or some of their units for redemption for a cash amount as determined by the partnership agreement and based on the fair value of our common stock. In lieu of a cash redemption by the partnership, we may elect to acquire any unit presented for redemption for one share of our common stock or for such cash amount. As of January 31, 2012, there were 7,500 DownREIT partnership units outstanding. The DownREIT partnership is consolidated for financial reporting purposes.

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Profile of Current, Development and Unconsolidated Communities (1)

(Dollars in thousands, except per apartment home data)