Costs of lease extension - tax deductible?

Hi there

I wonder if anyone could advise about how, from a tax perspective, to treat a statutory extension of a lease on a property rented out to tenants.

I can't seem to find a consistent viewpoint online so am a bit lost.

Are any of the following deductible from an income tax perspective:

1) cost of lease extension
2) solicitors fees and freeholders solicitors fees
3) property valuation for purpose of lease extension
4) extra related charges such as land registry cost etc

Or can the extension be treated as a capital allowance at all?

Thanks for your advice
Karen