if you paid for the plans then they are yours ,you can take them to other builder

Golden rule is don't believe or rely on any verbal promises they are useless ,everything needs to be in writing .Seems very unethical SC as they are all ,my house…

great advice from arcadelt, just to summarise:
building contract must be in writing
don't be bullied, they will do it right through the job
If your gut feeling is telling you run, then…