One of my specialities is dealing with investigations and I have been dealing with such cases for 15 years. Recently the Revenue have become much more picky with regards to expenses like these (it can't be cost effective!).
I am wondering whether this is the only area on your Return they have raised queries on, and if so it seems quite odd that such small amounts were queried unless you were unlucky and got picked 'at random'...
Ask the insurance company (not the broker)for a copy, unless you have lost the policy, changed insurers every year, or can't remember what they are called. Your mortgage company (if there is a mortgage) may also have been notified of the insurers name as it is a condition of most buy to let mortgages that buildings insurance is in place, and sometimes they do actaully check.
Failing that, ask the Inspector's boss to review the file regarding this as this just means completely unreasonable to me!
On the building work, tell the Inspector that the work was definitely done and invite him to allow the claim for the works or come down and view the property if he still refuses the claim, as the evidence of the work will be plain to see for anyone who has experience of such things. Alternatively, ask a friendly builder to have a quick look and get a letter from him stating in his professional opinion that works to the value of £478 has been performed. And if the Inspector still doesn't agree, get his boss to review the case and request that the investigation is closed down. Finally, if none of this works, ask the Inspector to list the case before the Commissioners as they are clearly wasting everyone's time and ask for costs to be awarded against the Revenue.
Ian McTernan CTA
McTernan Associates Ltd
ian@imcternan.com