41 C.F.R. §§ 102-83.135
For space acquisitions conducted by GSA, if, based on its review of a requesting agency's identified delineated area, GSA concludes that the requesting agency's identified delineated area should be modified, GSA will discuss its recommended changes with the requesting agency. If, after discussions, the requesting agency does not agree with GSA's delineated area recommendation, the requesting agency may appeal GSA's determination in accordance with § 102-83.140. If a requesting agency elects to ask for a review of GSA's delineated area recommendation, GSA will continue to work on the requirements development and other activities related to the requesting agency's space request. GSA will not issue a solicitation to satisfy an agency's space request until a final delineated area is determined through the appeal process.
41 C.F.R. §§102-83.135