How efficient will my conservatory be if I put a skylight in my conservatory roof? We are due to have a solid roof replacement and have an option to put a skylight in. The purpose of having a solid roof installed is so we can use the room all year roof. If we install a skylight will it negate this (back to a cold room)? Also would be its purpose - would it provide some good light from the sky? Is it worth the cost? We have an esst facing garden. The conservatory has floor to ceiling glass on two sides.