Building sites are areas of land that are designated for the construction of buildings. The three crossword solutions for the term 'building sites' are LOTS (4 letters), PLOTS (5 letters), and VACANTLOTS (10 letters). LOTS refers to a piece of land that is usually small in size, while PLOTS are larger pieces of land that are typically used for residential or commercial purposes. VACANTLOTS are pieces of land that have not yet been developed and are available for purchase.