DIY that will cost you

To many it is seen as a way of adding thousands to the value of their homes - but today experts warned that some "home improvements" could actually have the opposite effect.

They cited domestic horrors such as stone-cladding, UPVC windows, and avocado bathrooms.

And sinking money into "elitist" additions such as swimming pools can be a mistake.

The list of DIY no-no's was drawn up by Colin McAllister and Justin Ryan, previously of BBC2's Million Pound Property Experiment, and will be featured on new Five show The 20 Quickest Ways To Lose Money On Your Property, broadcast on Sunday at 8pm.

The pair claim owning pets can take £10,000 off the value, because new owners will be put off by the smell - and smoking could cost you up to £16,000.

Heavy patterns on furnishings and floors can knock £2,500 off values. But the most expensive single blunder is to avoid dealing with a severe structural problem such as subsidence. That can hit a home's value by up to £100,000.

Naomi Cleaver, presenter of Channel 4's Honey I Ruined the House, said another key mistake owners made was to concentrate on the inside of their home to the detriment of the outside.

"Stone cladding is particularly nasty because it is so inappropriate," she said.