In my campaign, I am using Ultimate Campaign rules to allow PCs to build houses, but not businesses or organizations. To generate capital, they're making skilled work checks. Their houses aren't businesses so don't generate capital. Mainly, they'll be building rooms that give them bonuses to saves and checks like lavatories and baths.
However, one PC wants to be a gardener. I know this isn't RAW, but if the gardener built a garden at his house, would it be overpowered to allow him to add the garden's +8 goods bonus to his skilled work checks to generate goods?