The short answer
The required foundation depends on the home, property, installation design, local rules, and financing program.
Use an approved installation plan
A certified installer should determine the support, anchoring, drainage, and foundation requirements for the site. The lender or building authority may require an engineered permanent foundation.
Match the foundation to the complete project
Give the installer the exact home information and the lender’s requirements before the foundation work is priced. Ask what site information or professional design is needed and who is responsible for inspections or certification.
Do not assume a foundation used for a previous home can be reused. A new home or financing arrangement may call for a different design. Keep the approved installation information and completion records with your home documents.
Ask who verifies completion
Before work starts, identify who checks the completed foundation and what records you will receive. Give the installer any lender or local-office requirements early enough to include them in the plan. Do not rely on a photograph of another installation as the specification for yours. The delivery-and-setup checklist below helps you track responsibilities without substituting for the installation instructions or a professional design.