Exhibit 21

List of Subsidiaries

AAPOP 2, L.P., a Delaware limited partnership

BDN 250 King of Prussia I, LP, a Delaware limited partnership

BDN 250 King of Prussia II, LP, a Delaware limited partnership

BDN Four Points LP, a Delaware limited partnership

BDN Four Points Land LP, a Delaware limited partnership

BDN Four Points Preserve LP, a Delaware limited partnership

BDNNOVA Momentum LP, a Delaware limited partnership

BDN Quarry Lake II, LP, a Delaware limited partnership

BDN Radnor Property I, LP, a Delaware limited partnership

BDN Radnor Property II, LP, a Delaware limited partnership

BDN Real Estate Fund I LP, a Delaware limited partnership

Bellet Holding GP, LP, a Delaware limited partnership

Brandywine Acquisition Partners LP, a Delaware limited partnership

Brandywine Austin Properties I LP, a Texas limited partnership

Brandywine Byberry LP, a Delaware limited partnership

Brandywine Cira Garage I LP, a Delaware limited partnership

Brandywine Cira, L.P., a Pennsylvania limited partnership

Brandywine Cira South LP, a Delaware limited partnership

Brandywine Cira Walnut I LP, a Delaware limited partnership

Brandywine Commerce I LP, a Delaware limited partnership

Brandywine Commerce II LP, a Delaware limited partnership

Brandywine F.C., L.P., a Pennsylvania limited partnership

Brandywine Garza Office I, LP, a Delaware limited partnership

Brandywine Garza Office II, LP, a Delaware limited partnership

Brandywine Garza Office III, LP, a Delaware limited partnership

Brandywine Grande C, L.P., a Delaware limited partnership

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Brandywine Greensboro Drive LP, a Delaware limited partnership

Brandywine International Drive LP, a Delaware limited partnership

Brandywine Industrial Partnership, L.P., a Delaware limited partnership

Brandywine Metroplex, L.P., a Pennsylvania limited partnership

Brandywine Midatlantic, LP, a Delaware limited partnership

Brandywine Office Investors LP, a Delaware limited partnership

Brandywine Operating Partnership, L.P., a Delaware limited partnership

Brandywine Opportunity Fund, LP, a Delaware limited partnership

Brandywine P.M., L.P., a Pennsylvania limited partnership

Brandywine Properties Management LP, a Texas limited partnership

Brandywine TB Florig, L.P., a Pennsylvania limited partnership

Brandywine TB I, L.P., a Pennsylvania limited partnership

Brandywine TB II, L.P., a Pennsylvania limited partnership

Brandywine TB VI, L.P., a Pennsylvania limited partnership

Brandywine TB VII, L.P., a Pennsylvania limited partnership

Brandywine 145 King of Prussia, LP, a Pennsylvania limited partnership

Brandywine 3001-3003 JFK, LP, a Delaware limited partnership

Brandywine 3001-3003 JFK II, LP, a Delaware limited partnership

Brandywine 3025 JFK, LP, a Delaware limited partnership

Brandywine 3025 Market, LP, a Pennsylvania limited partnership

Brandywine 3151 Market, LP, a Delaware limited partnership

Brandywine 3151 Venture, LP, a Delaware limited partnership

Chase Uptown West Property LP, a Delaware limited partnership

Cira Square Owner LP, a Delaware limited partnership

Cira Square PO LP, a Delaware limited partnership

Commerce Square Partners – Philadelphia Plaza, L.P., a Delaware limited partnership

Concord Airport Plaza Associates, LP, a California limited partnership

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Cooperative Way Metro Owner LLC, a Delaware limited liability company

Five/Oliver Brandywine Partner, L.P., a Pennsylvania limited partnership

Four Tower Bridge Associates, a Pennsylvania limited partnership

G&I VII Barton Creek LP, a Delaware limited partnership

G&I VII Barton Skyway LP, a Delaware limited partnership

G&I VII Cielo, LP a Delaware limited partnership

G&I VII Encino Trace I LP, a Delaware limited partnership

G&I VII Encino Trace II LP, a Delaware limited partnership

G&I VII Four Points LP, a Delaware limited partnership

G&I VII Lantana, LP a Delaware limited partnership

G&I VII River Place LP, a Delaware limited partnership

Iron Run Limited Partnership V, a Pennsylvania Limited Partnership

Newtech IV Limited Partnership, a Pennsylvania limited partnership

New Two Logan, LP, a Pennsylvania limited partnership

OLS Office Partners, L.P., a Delaware limited partnership

One Rockledge Associates Limited Partnership, a Massachusetts limited partnership

One Uptown Multifamily Property LP, a Delaware limited partnership

One Uptown Office Property LP, a Delaware limited partnership

Philadelphia Plaza – Phase II LP, a Pennsylvania limited partnership

Radnor Center Associates, a Pennsylvania limited partnership

Radnor Properties Associates-II, L.P., a Pennsylvania limited partnership

Radnor Properties-SDC, L.P., a Delaware limited partnership

Radnor Properties-200 RC Holdings, L.P., a Delaware limited partnership

Radnor Properties-200 RC, L.P., a Delaware limited partnership

Radnor Properties-201 KOP, L.P., a Delaware limited partnership

Radnor Properties-555 LA, L.P., a Delaware limited partnership

Two Logan Holdings LP, a Pennsylvania limited partnership

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Two Logan Square Associates, a Pennsylvania limited partnership

Tower Bridge Inn Associates, a Pennsylvania limited partnership

Witmer Operating Partnership I, L.P., a Delaware limited partnership

405 Colorado Holdings LP, a Delaware limited partnership

618 Market Street LP, a Delaware limited partnership

2100 Market Street LP, a Delaware limited partnership

2928 Walton Road LP, a Pennsylvania limited partnership

3000 Market LP, a Delaware limited partnership

3020 Market Holding LP, a Delaware limited partnership

3020 Market Operating LP, a Delaware limited partnership

Interstate Center Associates, a Virginia general partnership

Plymouth TFC, General Partnership, a Pennsylvania general partnership

BDN Management Inc., a Delaware corporation

Brandywine Holdings, I, Inc., a Pennsylvania corporation

Brandywine Properties I Limited Inc., a Delaware corporation

Brandywine Realty Services Corporation, a Pennsylvania corporation

Brandywine Resources I Inc., a Delaware corporation

Southpoint Land Holdings, Inc., a Pennsylvania corporation

BAA Multifamily Member LLC, a Delaware limited liability company

BAA Office Member LLC, a Delaware limited liability company

BAA Uptown West Member LLC, a Delaware limited liability company

BDN 250 King of Prussia II GP, LLC, a Delaware limited liability company

BDN 250 King of Prussia Holding Company, LLC, a Delaware limited liability company

BDN 3025 JFK Development, LLC, a Delaware limited liability company

BDN Austin Properties LLC, a Delaware limited liability company

BDN Austin Properties II LLC, a Delaware limited liability company

BDN Brokerage LLC, a Pennsylvania limited liability company

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BDN Cira Labs LLC, a Delaware limited liability company

BDN Cira Square Sub 1, LLC, a Delaware limited liability company

BDN Cira Square Sub Manager, LLC, a Delaware limited liability company

BDN Four Points GP LLC, a Delaware limited liability company

BDN Four Points Land GP LLC, a Delaware limited liability company

BDN Four Points Land 2 LLC, a Delaware limited liability company

BDN Four Points Preserve GP LLC, a Delaware limited liability company

BDN GC Services LLC, a Delaware limited liability company

BDN GP Real Estate Fund I LLC, a Delaware limited liability company

BDN Investment Holdings, LLC, a Delaware limited liability company

BDN Lending, LLC, a Pennsylvania limited liability company

BDN LS Investments, LLC, a Delaware limited liability company

BDN Management Holdings, LLC, a Delaware limited liability company

BDN Metroplex II Holdings LLC, a Delaware limited liability company

BDN Metroplex II Mezz LLC, a Delaware limited liability company

BDN Metroplex II Owner LLC, a Delaware limited liability company

BDN Metroplex II Sub 1 LLC, a Delaware limited liability company

BDN Metroplex II Sub 2 LLC, a Delaware limited liability company

BDN Metroplex III Holdings LLC, a Delaware limited liability company

BDN Metroplex III Mezz LLC, a Delaware limited liability company

BDN Metroplex III Owner LLC, a Delaware limited liability company

BDN Metroplex III Sub 1 LLC, a Delaware limited liability company

BDN Metroplex III Sub 2 LLC, a Delaware limited liability company

BDN Millennium Holding Company, LLC, a Delaware limited liability company

BDN NoMA LLC, a Delaware limited liability company

BDN Properties I LLC, a Delaware limited liability company

BDN Quarry Lake II GP, LLC, a Delaware limited liability company

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BDN Radnor Holding Company, LLC, a Delaware limited liability company

BDN Radnor Property II GP, LLC, a Delaware limited liability company

BDN SY Hospitality LLC, a Delaware limited liability company

BDN Uptown Office Developer LLC, a Delaware limited liability company

BDN-West Elm Holding LLC, a Pennsylvania limited liability company

BDNSY Mezz Sub, LLC, a Delaware limited liability company

BDN 500 North Gulph Holdings LLC, a Delaware limited liability company

BDN 500 North Gulph Mezz LLC, a Delaware limited liability company

BDN 500 North Gulph Owner LLC, a Delaware limited liability company

BDN 500 North Gulph Sub 1 LLC, a Delaware limited liability company

BDN 500 North Gulph Sub 2 LLC, a Delaware limited liability company

BDN 933 First Avenue Holdings LLC, a Delaware limited liability company

BDN 933 First Avenue Mezz LLC, a Delaware limited liability company

BDN 933 First Avenue Owner LLC, a Delaware limited liability company

BDN 933 First Avenue Sub 1 LLC, a Delaware limited liability company

BDN 933 First Avenue Sub 2 LLC, a Delaware limited liability company

BDN 1900 Market Holdings LLC, a Delaware limited liability company

BDN 1900 Market Mezz LLC, a Delaware limited liability company

BDN 1900 Market Owner LLC, a Delaware limited liability company

BDN 1900 Market Sub 1 LLC, a Delaware limited liability company

BDN 1900 Market Sub 2 LLC, a Delaware limited liability company

Bellet GP, LLC, a Delaware limited liability company

Bellet, LLC, a Delaware limited liability company

Brandywine Austin LLC, a Delaware limited liability company

Brandywine Austin I LLC, a Delaware limited liability company

Brandywine Austin Properties LLC, a Delaware limited liability company

Brandywine Brokerage Services, LLC, A New Jersey limited liability company

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Brandywine Byberry Holdings LLC, a Delaware limited liability company

Brandywine Byberry LLC, a Delaware limited liability company

Brandywine Byberry Sub Holdings LLC, a Delaware limited liability company

Brandywine Calverton LLC, a Delaware limited liability company

Brandywine Chase Uptown West LLC, a Delaware limited liability company

Brandywine Cira Brokerage LLC, d Delaware limited liability company

Brandywine Cira Garage LLC, a Delaware limited liability company

Brandywine Cira Garage Holding LLC, a Delaware limited liability company

Brandywine Cira Garage Holding MM LLC, a Delaware limited liability company

Brandywine Cira, LLC, a Pennsylvania limited liability company

Brandywine Cira South GP LLC, a Delaware limited liability company

Brandywine Cira Walnut LLC, a Delaware limited liability company

Brandywine Commerce I GP LLC, a Delaware limited liability company

Brandywine Commerce II GP LLC, a Delaware limited liability company

Brandywine Continental LLC, a Delaware limited liability company

Brandywine Dabney, L.L.C., a Delaware limited liability company

Brandywine F.C., L.L.C., a Pennsylvania limited liability company

Brandywine Garza, LLC., a Delaware limited liability company

Brandywine Garza Office I GP, LLC, a Delaware limited liability company

Brandywine Garza Office II GP, LLC, a Delaware limited liability company

Brandywine Garza Office III GP, LLC, a Delaware limited liability company

Brandywine Gibbsboro LLC, a Delaware limited liability company

Brandywine Grande C LLC, a Delaware limited liability company

Brandywine Interstate 50, L.L.C., a Delaware limited liability company

Brandywine Lake Merritt LLC, a Delaware limited liability company

Brandywine Lender, LLC, a Delaware limited liability company

Brandywine - Main Street, LLC, a Delaware limited liability company

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Brandywine Management Holdings II, LLC, a Delaware limited liability company

Brandywine MD Discovery District, LLC, a Delaware limited liability company

Brandywine Metroplex LLC., a Pennsylvania limited liability company

Brandywine Midatlantic, LLC, a Delaware limited liability company

Brandywine One Logan LLC, a Pennsylvania limited liability company

Brandywine One Rodney Square, L.L.C., a Delaware limited liability company

Brandywine One Uptown Multifamily LLC, a Delaware limited liability company

Brandywine One Uptown Office LLC, a Delaware limited liability company

Brandywine P.M., L.L.C., a Pennsylvania limited liability company

Brandywine Piazza, L.L.C., a New Jersey limited liability company

Brandywine Plaza 1000, L.L.C., a New Jersey limited liability company

Brandywine Promenade, L.L.C., a New Jersey limited liability company

Brandywine Radnor 200 Holdings LLC, a Delaware limited liability company

Brandywine Radnor Center LLC, a Pennsylvania limited liability company

Brandywine Research LLC, a Delaware limited liability company

Brandywine TB Florig, LLC, a Pennsylvania limited liability company

Brandywine TB I, L.L.C., a Pennsylvania limited liability company

Brandywine TB II GP, L.L.C., a Pennsylvania limited liability company

Brandywine TB VI, L.L.C., a Pennsylvania limited liability company

Brandywine TB VII, L.L.C., a Pennsylvania limited liability company

Brandywine Tysons LLC, a Delaware limited liability company

Brandywine Witmer, L.L.C., a Pennsylvania limited liability company

Brandywine 55 US Avenue LLC, a New Jersey limited liability company

Brandywine 300 Delaware, LLC, a Delaware limited liability company

Brandywine 2201 Co-Way LLC a Delaware limited liability company

Brandywine 2201 Co-Way II LLC, a Delaware limited liability company

Brandywine 3001 Market, LLC, a Delaware limited liability company

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Brandywine 3001-3003 HoldCo, LLC, a Delaware limited liability company

Brandywine 3001-3003 JFK II, LLC, a Delaware limited liability company

Brandywine 3025 JFK II, LLC, a Delaware limited liability company

Brandywine 3025 JFK II REIT, LLC, a Delaware limited liability company

Brandywine 3025 JFK Holdings II, LLC, a Delaware limited liability company

Brandywine 3025 Market Holdings, LLC, a Delaware limited liability company

Brandywine 3151 Market GP, LLC, a Delaware limited liability company

Brandywine 3151 Market REIT, LLC, a Delaware limited liability company

BRE/Logan I, L.L.C., a Delaware limited liability company

BRE/Logan II, L.L.C., a Delaware limited liability company

BRE/Logan III, L.L.C., a Delaware limited liability company

Chase Uptown West GP LLC, a Delaware limited liability company

Chestnut Venture LLC, a Delaware limited liability company

Cira Square, LLC, a Delaware limited liability company

Cira Square G Member, LLC, a Delaware limited liability company

Cira Square GP, LLC, a Delaware limited liability company

Cira Square Master Tenant LLC, a Delaware limited liability company

Cira Square PO LP LLC, a Delaware limited liability company

Cira Square REIT, LLC, a Delaware limited liability company

Cira Square TopCo LLC, a Delaware limited liability company

Cira Square TRS LLC, a Delaware limited liability company

Cira Square II, LLC, a Delaware limited liability company

Cira Square III, LLC, a Delaware limited liability company

Cira Square IV, LLC, a Delaware limited liability company

e-Tenants LLC, a Delaware limited liability company

G&I VI 7150 Windsor MZ LLC, a Delaware limited liability company

G&I VI 7310 Tilghman MZ LLC, a Delaware limited liability company

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G&I VI 7310 Tilghman FE LLC, a Delaware limited liability company

G&I VI 7248 Tilghman GP LLC, a Delaware limited liability company

G&I VI 7248 Tilghman LP LLC, a Delaware limited liability company

G&I VI 6575 Snowdrift GP LLC, a Delaware limited liability company

G&I VI 6575 Snowdrift LP LLC, a Delaware limited liability company

G&I VI 7350 Tilghman MZ LLC, a Delaware limited liability company

G&I VI 655/755 Business Center MZ LLC, a Delaware limited liability company

G&I VI 655/755 Business Center FE LLC, a Delaware limited liability company

G&I VI 1155 Business Center MZ LLC, a Delaware limited liability company

G&I VI 1155 Business Center FE LLC, a Delaware limited liability company

G&I VI 700/800 Business Center MZ LLC, a Delaware limited liability company

G&I VI 700/800 Business Center FE LLC, a Delaware limited liability company

G&I VI 630 Dresher MZ LLC, a Delaware limited liability company

G&I VI 630 Dresher FE LLC, a Delaware limited liability company

G&I VI 650 Dresher MZ LLC, a Delaware limited liability company

G&I VI 650 Dresher FE LLC, a Delaware limited liability company

G&I VI 300 Welsh 1/2 MZ LLC, a Delaware limited liability company

G&I VI 300 Welsh 1/2 FE LLC, a Delaware limited liability company

G&I VI One Greenwood MZ LLC, a Delaware limited liability company

G&I VI One Greenwood FE LLC, a Delaware limited liability company

G&I VI Two Greenwood MZ LLC, a Delaware limited liability company

G&I VI Two Greenwood FE LLC, a Delaware limited liability company

G&I VI Three Greenwood MZ LLC, a Delaware limited liability company

G&I VI Three Greenwood FE LLC, a Delaware limited liability company

G&I VI 500 Office Center MZ LLC, a Delaware limited liability company

G&I VI 500 Office Center FE LLC, a Delaware limited liability company

G&I VI 501 Office Center MZ LLC, a Delaware limited liability company

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G&I VI 501 Office Center FE LLC, a Delaware limited liability company

G&I VI 321/323 Norristown MZ LLC, a Delaware limited liability company

G&I VI 321/323 Norristown FE LLC, a Delaware limited liability company

G&I VI 220 Commerce MZ LLC, a Delaware limited liability company

G&I VI 220 Commerce FE LLC, a Delaware limited liability company

G&I VI 520 Virginia MZ LLC, a Delaware limited liability company

G&I VI 520 Virginia FE LLC, a Delaware limited liability company

G&I VI Interchange Office LLC, a Delaware limited liability company

G&I VII Austin Office LLC, a Delaware limited liability company

G&I VII Barton Creek GP LLC, a Delaware limited liability company

G&I VII Barton Skyway GP LLC, a Delaware limited liability company

G&I VII Cielo GP LLC, a Delaware limited liability company

G&I VII Encino Trace I GP LLC, a Delaware limited liability company

G&I VII Encino Trace II GP LLC, a Delaware limited liability company

G&I VII Four Points GP LLC, a Delaware limited liability company

G&I VII Lantana GP LLC, a Delaware limited liability company

G&I VII River Place GP LLC, a Delaware limited liability company

HSRE-BDN I, LLC, a Delaware limited liability company

MAP Ground Lease Venture LLC, a Delaware limited liability company

MAP Mezzanine Borrower LLC, a Delaware limited liability company

MAP Ground Lease Owner LLC, a Delaware limited liability company

Mid-Atlantic Property Holdings LLC, a Delaware limited liability company

New Two Logan GP, LLC, a Pennsylvania limited liability company

OCS Sub, LLC, a Delaware limited liability company

OCS/TCS Services, LLC, a Delaware limited liability company

OCS TRS, LLC, a Delaware limited liability company

One Commerce Square REIT LLC, a Delaware limited liability company

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One Uptown Multifamily GP LLC, a Delaware limited liability company

One Uptown Office GP LLC, a Delaware limited liability company

PA-MD NNN Berwyn Park, LLC, a Delaware limited liability company

PA-MD NNN Office JV, LLC, a Delaware limited liability company

PA-MD NNN Office Mezz, LLC, a Delaware limited liability company

PA-MD NNN Office Research, LLC, a Delaware limited liability company

PA-MD NNN Office Southpoint, LLC, a Delaware limited liability company

Radnor GP, L.L.C., a Delaware limited liability company

Radnor GP-SDC, L.L.C., a Delaware limited liability company

Radnor GP-200 RC, L.L.C., a Delaware limited liability company

Radnor GP-201 KOP, L.L.C., a Delaware limited liability company

Radnor GP-555 LA, L.L.C., a Delaware limited liability company

PJP Building Six, L.C., a Virginia limited liability company

TCS Sub, LLC, a Delaware limited liability company

TCS TRS, LLC, a Delaware limited liability company

Two Commerce Square REIT LLC, a Delaware limited liability company

Walnut Street Hospitality LLC, a Delaware limited liability company

3 Logan LLC, a Delaware limited liability company

165 Radnor Hotel LLC, a Delaware limited liability company

165 Radnor Hotel Holdco LLC, a Delaware limited liability company

405 Colorado Holdings GP LLC a Delaware limited liability company

618 Market Holdco General Partner LLC, a Delaware limited liability company

618 Market Mezz Holdco LLC, a Delaware limited liability company

2100 Market Holdco General Partner LLC, a Delaware limited liability company

2100 Market Mezz Holdco LLC, a Delaware limited liability company

2251 Corporate Park Metro Owner LLC, a Delaware limited liability company

2291 Wood Oak Metro Owner LLC, a Delaware limited liability company

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2411 Dulles Corner Metro Owner LLC, a Delaware limited liability company

2355 Dulles Corner Metro Owner LLC, a Delaware limited liability company

2928 Walton LLC, a Delaware limited liability company

3000 Market Mezz LLC, a Delaware limited liability company

3000 Market Mezz Holdco LLC, a Delaware limited liability company

3000 Market Holdco General Partner, LLC, a Delaware limited liability company

3020 Market Holding GP LLC, a Delaware limited liability company

3025 Food Hall LL LLC, a Delaware limited liability company

3025 JFK TRS LLC, a Delaware limited liability company

4040 LLC, a Virginia limited liability company

4040 Wilson LLC, a Delaware limited liability company

51 N 50 Patterson Holdings, L.L.C., a Delaware limited liability company

51 N 50 Patterson Corporate Member, L.L.C., a Delaware limited liability company

13880 Dulles Corner Metro Owner LLC, a Delaware limited liability company

13825 Sunrise Valley Metro Owner LLC, a Delaware limited liability company

1000 Chesterbrook Boulevard Partnership, a Pennsylvania general partnership

Atlantic American Properties Trust, a Maryland real estate investment trust

Brandywine Capital Trust I, a Delaware statutory trust

Brandywine Capital Trust II, a Delaware statutory trust

Broadmoor Austin Associates, a Texas joint venture

Coppel Associates, a Texas joint venture

Seven Tower Bridge Associates, a Pennsylvania limited partnership

Brandywine – AI Venture LLC, a Delaware limited liability company

G&I VI Interchange Office LLC, a Delaware limited liability company

G&I VII Austin Office LLC, a Delaware limited liability company

Herndon Innovation Center Metro Portfolio Venture LLC, a Delaware limited liability company

Iron Run Venture II LLC, a Delaware limited liability company

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One Rockledge Associates Limited Partnership, a Massachusetts limited partnership

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