You should keep one full set of your plan documents for your personal records. In order to build your home, you will need extra sets for your builders and contractors for them to accurately bid on your home. Plus, you need copies for your lending institution and local building department. You can visit your local building department’s website to find out how many copies are needed. We do recommend buying an electronic PDF of your plans because you can print multiple copies. Most builders, contractors, and banks use PDF format.