We're looking at a plot that has a house on it that was built around 40 years ago. It's gone through many owners since then. 

 

We would look at knocking the house but are interested in the plans that show the foundations etc, as we may build a small guesthouse, or place a knockdown house on it, still keep part of it, or may use the foundations and pipes etc for something or other.

 

Is it possible to get the original house plans that were drawn up from a local office? Do they keep them on file the same as the title deeds? The current owner can be present with their Thai ID and title deeds. 

 

Or are they not kept on file? 

 

TIA. 

Usually house plans are lodged with the local Tessabaan, not with the Land office. Doubtful they will still have plans from 40 years ago.

Knock down the area first and check the foundations etc at that point. That will show you how the posts, beams, slab, possibly some plumbing etc were built. then go from there.

Why would you use 40 year old foundations and pipes etc on a new build. Just knock it all down and start from scratch. 

Is it just built on a slab or are there steps up to it, can you not see any plumbing from outside?