I'm currently making plans to upgrade an old Outhouse and Coal Store on the back of my 1950's end terrace house in to a utility room. The cavity wall from the house extends to incorporate the Outhouse, but the coal store only has a single brick wall construction.
As this needs to be converted to a cavity wall (to satisfy building regs), what do I have to do with the foundations?
The house sits on foundations 600mm below the DPC - not the full 1m now required by Building Regs. Can I just dig to the existing 600mm foundations to start my cavity wall brickwork, or do I have to go to 1m? None of my new walls will be load bearing (apart from their own weight!)
Hope you can give me some advice!