I've got a small wooden conservatory behind my attached garage, It's suffering from rot as it's sitting straight on top of the paving stones with no DP membrane. Currently, you step down from the kitchen about 400mm into the conservatory then up 200mm to enter the garage. I want to replace the conservatory with upvc, can I raise the floor level to be the same as the garage or has it got to be 100mm higher to comply with regs?
Thanks