Subdivision & Sellout Property Appraisal Documents Needed PSP , Preliminary Site Plan Approved, at a minimum. This document shows the layout of lots, streets, common areas, retention, etc. A civil engineering firm will create your plat and submit it to the local planning department for approval. The first step in the approval process is Preliminary Site Plan (PSP) approval. Purchase Contact Shows price paid for “Blanks”, an industry term used to describe raw land approved for subdivision development. Infrastructure Cost The cost to construct underground utilities, roads, accel / decel lanes, etc Ratio Analysis as a "Road Map" Take the average retail price of a finished home, multiply by 35% and you get the "indicated" retail value of each lot. Ratio analysis give you a "guide" to go by for a quick check of economic feasibility and for "comp selection". Example (Assume) 100 lots in a subdivision with homes that sell for an ave