Readers' forum: Separate disposal?

I act for an electrical contractor who has been engaged to do work for a customer who is self-building his own premises. The property in question is a barn conversion. I do not have all of the relevant details but from what my client has told me the planning required that only one wall was to be removed at a time while foundations were dug and then the wall rebuilt in stages. My client initially said this is a new build therefore we should zero rate it at which point I said that we needed to consider this further.

I believe that because this is a barn conversion (and we are unlikely to be able to treat it as a new build) it should be a conversion from non-residential to residential and my client will charge 5% VAT. However I also have concerns that the property being...