Unfortunately finding good builders in Thailand is a crap shoot.
There are no licensing laws regarding builders. Anyone can put out a sign and claim to be a builder.
My brother in law and sister in law just finished having their dream home built in Hua Hin. It took almost 2 years to complete, the builder never quite finished the building before he ran out of "their" money and they had to move into the unfinished house.
To their horror and disgust they found lots of things that were done sloppy and incorrectly. The builder doesn't return any of their calls and they are resigned to finishing up the work on their own and paying to have other things entirely redone.
A warning to anyone who is planning on building a house in Thailand.
1.Do your homework. If you find a builder ask to see some of his construction jobs. Ask him to point out houses he has recently built...then go back later and interview the homeowners. See what they like and didn't like.
2.Make sure you are there while the construction is being done. Many foreigners "trusted" a builder to build their Thai dream house only to find that when they fly to Thailand...little work or nothing has been done.
Be there so you can monitor all the steps and make sure you are getting exactly what your contract specifies. Our sister in law ended up with doors and windows and fixtures that weren't the ones she picked out when she went shopping with the builder originally
3. Don't rely on an real estate agent to recommend a good builder. Usually how it works is that the agent gets a cut out of the builders fee. So you end up getting overcharged or the quality of the home is lowered
4. My sister in law says that if she had to do it all over again she would just hire people to do the work and she would serve as the contractor herself.
5. Home Construction quality in Thailand is often poor. There are few minimum building standards, no city inspectors, no rules and regulations to follow. It is largely an unregulated industry.
One look at the quality of concrete work on a typical Thai sidewalk should convince you that the best advice in Thailand is "LET THE BUYER BEWARE"
6. Double check anyone who recommends a good builder. You might be surprise that it's the guy is recommending himself..or someone he works with.