Readers' forum : Garden shed

My client is a self-employed carpenter. As well as carrying out work in the homes and premises of clients he has to do much preparation at home. Because his business has expanded he has recently demolished his garden shed and replaced it with a more substantial workshop. He seems to expect that the full cost of about £15 000 can be included as a deduction in his accounts. He tells me that a friend of his has done this. My first thought was that this is a capital item so no deduction can be made against income but now I am not so sure.

The shed includes work benches and shelving and there is also a separate fused electricity supply. From the receipts provided the workshop has a heating system and the water supply has been extended to it and a sink fitted.

I am wondering whether...