Property CGT allowable expense - historical rules

Hi, The rules on what counts as an allowable expense for CGT purposes, i.e. an improvement as opposed to a repair, change over time. For example, it appears that replacing single glazing with double glazing used to be viewed as an improvement, but is now seen as a repair and therefor cannot be offet for CGT purposes. Question: If I sell a property now, which rules should I use to decide whether to deduct specific historical expenses or not? I expect this would be the rules in force at the time of the expense - if correct, then where can I find those rules? Thanks!

Hi,

You can see guidance which advises the four areas where expenditure is allowable here: 

CG15150 - Expenditure: introduction

The rules on revenue expense and capital allowances are open to interpretation, so it is largely a question of fact and degree in each case whether expenditure on a property leads to an improvement. The following guidance advises that sometimes the improvement may be so small as to count as incidental to a repair. In the absence of other capital indications, the entire cost is then revenue expenditure. Problems can arise where the customer does work on an old asset. A repair or replacement of a part of a building using modern materials may give an apparent element of improvement because of the greater durability, superior qualities and so forth of the new material. But the cost normally remains revenue expenditure where any improvement arises only because the customer uses new materials that are broadly equivalent to the old materials. Your example of single glazed and double glazed windown falls into this category. 

PIM2030 - Deductions: repairs: is it capital?

Thank you.