Yeah that could be an option at the discretion of the seller. If I was selling a house I would want 144 blocks (24 hours).
Or 144 blocks with time minimum. Something like 32 block extension if 144+extension*(blocks per extension) blocks are hit before 24 hours have passed. A detail but you get the idea
Good luck to itod/profMac and/or whoever else gets into this. Would be nice to see.
Sorry for the offtopic also.
While I think it is on topic, I have started another thread to support a needs analysis for blockchain auctions.