Capital allowances are not claimable for most residential properties - instead, landlords with unfurnished properties can claim a 'renewals basis' allowance for 'moveable items' such as white goods, carpets, curtains (imagine you could pick up a house and turn it upside down - what falls out are 'moveable items' - generally).

However, this 'renewals allowance' was actually an 'Extra Statutory Concession' (ESC) by HMRC, and so did not have the force of law - in other words it was an allowance that HMRC gave but were not obliged to give.

As part of an ongoing effort to 'tidy up' the tax system, HMRC have been removing certain ESCs. HMRC have used ESCs as a 'work-around', where it's far easier to just accept a particular tax treatment rather than go through the lengthy and expensive process of actually amending tax law - which has to go through a formal Parliamentary process. However, the 'Wilkinson' case in the House of Lords essentially gave HMRC a 'telling off' for going too far in using ESCs.