Legal Question in Real Estate Law in California

It may depend upon what you mean by "house". If you mean a home as real estate, rather than a mobile home or something like that, physical delivery (in any sense) is no longer required. In ancient times, there was a concept called "livery of seizin" under which a seller of real estate had to make a (largely symbolic) delivery of some part of the property to the buyer -- a key, a handful of earth, a twig -- to constitute delivery of the entire property. This is no longer necessary at all.

Delivery of a deed from the seller to the buyer is still necessary to convey real estate. However, even this requirement has been somewhat watered down in modern practice. The deed is usually prepared by an escrow company, acting as agent for both the buyer and seller, and recorded by the escrow company after the seller signs at closing. Delivery of the deed to the agent of the buyer constitutes delivery to the buyer, and this is sufficient.

Perhaps you mean physical possession of the property. If the seller continues to reside in a sold house after the title (ownership) changes hands, this has no effect on ownership per se. The seller is either there with permission of the new owner, or without permission. If the seller doesn't have the buyer's permission, he is probably one step up from being a pure trespasser--he's probably a low-ranking type of tenant, but one you can evict promptly by following the correct procedure.

I suggest you ask a follow-up question giving a few more details, or contact me directly.

I agree with Mr. Whipple. Ownership of real property, meaning land and the things attached to it, is delivered by a "deed." Once you have a deed and want possession, you must get a court order to have occupiers of the property evicted.

But you may be referring to something else, like a mobile home, which is governed by other laws.