Hi Leannet77,
As the property was not your main residence during your period of ownership, Private Residence Relief is not available.
Re-wiring, new windows, kitchens, bathrooms etc, are normally considered as repairs and maintenance and do not normally qualify as a capital allowance.
The work to change the building, would qualify for capital allowances, such as the stud wall, re-wiring those rooms.
Where an asset was acquired for a value, significantly lower than the normal market value, because it is in a poor state of repair, then those cost of bringing it up to standard may be allowable as capital allowances.
Please have a look at the guidance here:
CG15150 - Expenditure: introduction
Onwards, re expenditure and enhancements.
Thank you.