Insualtion as an expense on let property

[FarmerBill]

Have I spent some money insulating a residential property that I let out, and also insulating a barn that I let out as commercial units.

Am I correct in thinking that I can claim the barn insulation as an expense, but not the residential property? And if so what is the logic behind this?

While looking it there seems to have been an allowance for insulating domestic property but this finished in April 2019. I would be grateful for some advice.

[pawncob]

Depends on the definition of a dwelling.
https://www.property118.com/member/?id=698

HMRC say no allowance for a house.
https://www.gov.uk/hmrc-internal-manuals/capital-allowances-manual/ca22220

[bd6759]

Just to clarify, the cost is a capital expense and not deductible in the accounts.

The references by pawncob are for capital allowances. Insulation qualifies, but not if it is in a dwelling house.