Design crimes cost dear

You may think your gnome looks wonderful and welcoming as he stands in the garden - but did you know he could knock £500 off the price of your house?

Those brightly painted walls could cost you up to £ 1,000 when you come to sell, as could that limescale build-up in the bathroom.

And if you've installed modern windows in your period property, then you can take £10,000 off its selling price.

These style blunders, decorative mistakes and maintenance problems are among a list of 'design crimes' that can leave homeowners thousands of pounds out of pocket when they sell.

The list was compiled for a BBC programme, The Million Pound Property Experiment, and shows how psychological factors influence the sale of a house.

'If you are walking towards a property and there are 25 gnomes in the garden, it makes a prospective buyer question the design sensibilities of the owner,' said Justin Ryan, who presents the series with fellow property consultant Colin McAllister.

'A gnome can knock £500 off your house's value.

'If you haven't watered your plants, then it looks like you don't care about your house. Similarly, if you have limescale in your bathroom, the subliminal message is that you could have plumbing problems.'

The survey reveals that carpets in the bathroom or kitchen can give the impression there is a concealed dampness. The cost of that error is £1,300.

Other things to avoid are gloomy lighting, pebble-dashed walls and violently patterned carpets.

Joint top of the list was a problem familiar to many casual DIY enthusiasts - the paint-splattered light switch.

'It doesn't sound like a major problem but a grubby light switch hints at old, possibly neglected wiring,' said Mr McAllister. 'We would knock £3,000 off the offer price for an average house.'