"In through the nose, and out through the mouth, in through the nose, and out through the mouth......"
This is a common occurrence. My husband works in the construction industry and cordially dislikes all architects. I won't tell you what he says about them as it is too rude to write.
Take heart. You've seen Grand Designs - it always goes like that and the finished house/extension/barn/windmill/tree house always looks wonderful at the end!
At least you have flowers to contemplate. I hope that all conflict will soon be resolved.
I prescribe a BIG mug of strong builders' tea with a couple of biscuits of the HobNob kind ..... for you , that is .Good Luck !