I had one design firm tell me 10k from start to finish. I had another charge $1 sq foot and another charged by the hr.

An entirely custom home should be designed by an architect. If you desire the interior spaces to be complimentary to the design theme, hire an interior designer to work with the architect early in the design process along with you, the homeowner. If you explore these forums in the building a home section, you will see strong opinions on designing a home from the inside out instead of the outside in. As to costs, there are too many variables such as location, size home, style home, etc. to make an educated guess. It’s possible to find “interior designers “ who charge from DC to light, depending on what you want and the size of your budget. Best wishes on your new project.

We paid our interior designer $18k to do the interior design of our home. This included drawings for all kinds of things like kitchen, bathrooms, window trim, fireplace wall, layouts for towel bars, lighting locations and so on. Lots of stuff. Our house is 4400 square feet but we did the interior design for the 800 square foot suite ourselves.

We also used her for our architectural plans. This was a fully custom home. We don’t live in the US and we felt the extra qualifications she had were sufficient for architectural design too. We were not disappointed. This cost $20 k.

I didn't pay me.