Various embodiments set forth systems and techniques for determining expandability of a budding design. The techniques include receiving a building geometry indicating a size of a building and a shape of the building; receiving building placement data indicating a placement of the building within a site; identifying one or more remaining spaces within the site based at least on the size of the building, the shape of the building, and the placement of the building within the site; for each remaining space of the one or more remaining spaces: determining whether the remaining space is a usable space; based on the determining whether the remaining space is a usable space, generating a space expansion value corresponding to the remaining space; and computing, based on space expansion values corresponding to the one or more remaining spaces, one or more aggregate expansion values associated with the building geometry and the building placement.