It don't think it would be "too" much if the granite is prominent in a give room. There is certainly a justification for it if you place any plantings or other moisture containing items there.

Ask the window installer about the dimensions on the lower rail/frame and if the granite can be installed after the fact more easily.

Pictures would help.

Pictures....

A little dark, lights are off and it was afternoon when I took the picture. Table and rug are being replaced with a lighter and round version.

I think it wouldn't look weird in the kitchen but the bay window might be a bit much. For me, it would look too detached, sort of like an afterthought.

Thanks Carolina K&B, I'm thinking over the sink only too. My husband is concerned that even that would be too much with it being Fantasy Brown (would make sure the "grain" was going the same way. We will be installing a simple backspash.

Some granites don't require a sealer and some require more than others and applied more frequently. I too have granite at one of my rentals on the window sills, countertops and entry floor. They have never been sealed and are not stained. This was done back in 1995, do has stood the test of time and abuse. I may be rude but you must be insulted frequently.

I think the Bay Area may be too much as well.

Thanks everyone-I have definitely decided not to put granite in the bay window sills in the nook. I did assume that granite sills would be sealed and treated in the same manner as the counter top. I would want to make sure the sill was protected just in case I place potted herbs, etc. above the sink. Have a great day!