House Doctor: 'Will adding an extension help us find a buyer for our house?'

Question: We put our house on the market in mid-2010 for £175,000-ish but got absolutely nowhere, although plenty viewed and said they liked it.

However, we really need to sell to downsize and want to add extra value by adding another bedroom and bathroom above the garage.

The mortgage was paid off years ago, so we can afford to spend up to £15,000. Is there any way to work out if an extra bedroom and bathroom will be enough?

Will Jones, Liverpool

Answer: Desperation to move can spark many sentiments but willingness to spend up to £15,000 to find a buyer is as frantic as they come.

While an extension will add intrinsic value, there's sadly no guarantee any potential buyer will either feel any further attraction to your property or be prepared to pay the asking price for it.

With prices in the doldrums, trying to find a buyer is a tricky business. Creating extra space won't harm a property, says Gavin Brazg at advice site, "as long as you know what your buyers' tastes and preferences are". This involves research and a visit to at least three estate agents to ask which home improvements have been notable in sales during the past couple of years, and then sites such as to discover how much those properties sold for.

According to research by Nationwide building society, an extra bathroom can add 5.2 per cent to a property value; a bedroom 6 per cent; off-street parking 6.5 per cent and a loft conversion (extra room/bathroom) 20 per cent. Yet this could be expensive and laborious (in the shape of planning applications).

Your best bet is most likely much simpler – put your home up for sale for much less.

"Many homeowners still struggle enormously with the idea of dropping their price in today's market, especially when they remember what they could have got if they'd sold in 2007," says Andrew Montlake at mortgage broker Coreco.

Try a drop of up to 10 per cent in asking price from last summer; it's usually enough to bring back many previous viewers, and you can do this without spending a penny.

Alternatively, price your property at five per cent less to attract buyers but then use a willingness to accept a further five per cent drop as a negotiating tool.