Our builder purchased and installed the wrong windows. We specified, in writing, wood/clad grilles and they ordered the snap-in kind. The mistake was obviously costly. We tried to do them a big favor by keeping some of the non-grille windows and leaving the snap-in grilles off. This saved them thousands. The most cost effective way for them to fix the rest of the windows was to order new windows, take the sashes off the new windows and put them on the already installed window frames.

We are finishing up the house and just got the final numbers. They billed us for all of the extra windows they had to buy, and the labor involved, to fix their mistake. We have a cost-plus contract. Am I wrong to think this is completely inappropriate? We like our builder a lot and were shocked that they felt we should pay for the mistake.

I'd appreciate any input.