Can I build a room on a land which used to be pool.?

Question

I like to buy a house which had swimming pool and septic tank long long time ago. Apparently it is filled and looks like a garden now.

Can I construct an extension of the house on this filled area if city allows it? Do you know how expensive it will be? Any addtional steps to be done?

This is in california

Do you know anyone who has done such a thing?

Answer 1

Whenever you add to any structure, you have to make sure the soil is stable.

If your California home is built on a below grade foundation, you addition will also have to be built on a below grade foundation. The footings for the foundation have to be poured on solid stable ground - no organic mater beneath them. This may mean excavating lower than the existing foundation to get to solid undisturbed earth.

If your California home is built on a slab foundation, your addition will have to be built on a slab foundation. This will mean excavating to solid undisturb earth and filling and compacting with the proper fill.

As was stated previously - check with the local build planning/inspect department.

If the Septic Tank is still in the ground, it will have to be removed.

This can be a very costly undertaking.

PS: We have an addition that part of the foundation is actually and old concrete inground swimming pool floor. We had to have it inspected before using it as a footing. We also had to do a leveling pour where the deep end was. It was quite an engineer to join it with rest of the foundation for the addition. It was done about 25 years ago and has not moved.

Answer 2

only your local building official knows for sure