16. Commitments and Contingencies Our properties require periodic investments of capital for general capital improvements and for tenant related capital expenditures. We enter into various construction and equipment contracts with third parties for the development of our properties. At December 31, 2016, we had open commitments related to construction contracts of approximately $18.6million. Additionally, we have commitments related to telecommunications capacity used to connect data centers located within the same market or geographical area, power usage, and company-wide improvements that are ancillary to revenue generation. At December 31, 2016, we had open commitments related to these contracts of approximately $10.3million. We have agreed with affiliates of the Carlyle Group that have directly or indirectly contributed their interests in the properties in our portfolio to our Operating Partnership that if we directly or indirectly sell, convey, transfer or otherwise dispose of all or any portion of these interests in a taxable transaction, we will make an interest-free loan to the contributors in an amount equal to the contributors tax liabilities, based on an assumed tax rate, with respect to built-in-gains generated from the initial contribution. These tax protection provisions apply for a period expiring on the earliest of (i) the seventh anniversary of the completion of our IPO, September 23, 2017, and (ii) the date on which these contributors (or certain transferees) dispose in certain taxable transactions of 90% of the Operating Partnership units that were issued to them in connection with the contribution of these properties. We entered into a Memorandum of Understanding with the Virginia Economic Development Partnership Authority (the Virginia Memorandum of Understanding) pursuant to which we are afforded the opportunity to benefit from an exemption from sales and use tax for certain qualifying data center related purchases and equipment leases. This exemption also extends to our customers who e