Does anyone know if it is an absolute requirement to for your Thai husband to have house registration papers in order to extend a Non-Immigrant 'O'? He is on house registration papers with about 8-9 other people, but we do not live in that house. We are planning to build a new one soon, but for the time being we rent.

Yes, it is absolutely required. That and an ID card and marriage license. It doesn't matter if he doesn't own the house he is registered in, but he does have to have one. Check with immigration if you need to apply in the province that he is registered in, that one I am not sure of.

Believe he just must be listed on a home registration; as you report he is. He would have to take the paperwork and copies on the day he applies to extend your visa.