Can I get a tax break on my garden office?

Just had a brain wave. Can I claim back some the costs of a garden office from my tax bill?

I can’t see why not. I can claim some of the expenses of running my home office, heating, electricity etc. - surely the cost of the building itself would be eligible.

This is one for my accountant.

I’ll provide an update when I have the result.

Update:

So: yes and no.

Yes to everything INSIDE, like equipment, lighting, carpet and what not. No to the actual building.