in particular , we have received commitments for $ 30.0 billion in debt financing to fund the transactions which is comprised of ( i ) a $ 4.0 billion secured revolving credit facility , ( ii ) a $ 7.0 billion term loan credit facility and ( iii ) a $ 19.0 billion secured bridge loan facility . our reliance on the financing from the $ 19.0 billion secured bridge loan facility commitment is intended to be reduced through one or more secured note offerings or other long-term financings prior to the merger closing . however , there can be no assurance that we will be able to issue any such secured notes or other long-term financings on terms we find acceptable or at all , especially in light of the recent debt market volatility , in which case we may have to exercise some or all of the commitments under the secured bridge facility to fund the transactions . accordingly , the costs of financing for the transactions may be higher than expected . credit rating downgrades could adversely affect the businesses , cash flows , financial condition and operating results of t-mobile and , following the transactions , the combined company . credit ratings impact the cost and availability of future borrowings , and , as a result , cost of capital . our current ratings reflect each rating agency 2019s opinion of our financial strength , operating performance and ability to meet our debt obligations or , following the completion of the transactions , obligations to the combined company 2019s obligors . each rating agency reviews these ratings periodically and there can be no assurance that such ratings will be maintained in the future . a downgrade in the rating of us and/or sprint could adversely affect the businesses , cash flows , financial condition and operating results of t- mobile and , following the transactions , the combined company . we have incurred , and will incur , direct and indirect costs as a result of the transactions . we have incurred , and will incur , substantial expenses in connection with and as a result of completing the transactions , and over a period of time following the completion of the transactions , the combined company also expects to incur substantial expenses in connection with integrating and coordinating our and sprint 2019s businesses , operations , policies and procedures . a portion of the transaction costs related to the transactions will be incurred regardless of whether the transactions are completed . while we have assumed that a certain level of transaction expenses will be incurred , factors beyond our control could affect the total amount or the timing of these expenses . many of the expenses that will be incurred , by their nature , are difficult to estimate accurately . these expenses will exceed the costs historically borne by us . these costs could adversely affect our financial condition and results of operations prior to the transactions and the financial condition and results of operations of the combined company following the transactions . item 1b . unresolved staff comments item 2 . properties as of december 31 , 2018 , our significant properties that we primarily lease and use in connection with switching centers , data centers , call centers and warehouses were as follows: .
what was the average size of the 61 switching centers in square feet
as of december 31 , 2018 , we primarily leased : 2022 approximately 64000 macro towers and 21000 distributed antenna system and small cell sites . 2022 approximately 2200 t-mobile and metro by t-mobile retail locations , including stores and kiosks ranging in size from approximately 100 square feet to 17000 square feet . 2022 office space totaling approximately 1000000 square feet for our corporate headquarters in bellevue , washington . in january 2019 , we executed leases totaling approximately 170000 additional square feet for our corporate headquarters . we use these offices for engineering and administrative purposes . 2022 office space throughout the u.s. , totaling approximately 1700000 square feet , for use by our regional offices primarily for administrative , engineering and sales purposes. .