DIY disasters and cluttered bedrooms could knock £10,000 off the price of an average home in the UK, a panel of experts has suggested.

The group, put together by online local services marketplace Bark.com, also said a messy garden could devalue a property by up to 20%.

The panel, consisting of 20 estate and lettings agents, interior decorators, plumbers and gardeners, said homeowners were much better off adding an off-road parking space to a property – which could increase its value by up to 10% – while replacing a dated bathroom suite could boost a home’s value by £2,500.

The experts also revealed that, on average, homeowners in the UK planning a renovation of their property in the next year will spend over £20,000 on home improvements.

Using the expert panel, Bark.com has created a comprehensive guide to help homeowners sell their home for the highest possible asking price. The full guide – which can be found here – outlines the top buyer bugbears, which includes evidence of pets, illegal improvements, overgrown gardens, poor parking and unusual décor.

Other factors which are likely to put buyers off include expensive additions such as solar panels, the performance of local schools, antisocial neighbours, outdated appliances and poor energy efficiency.

Superstition can also play a part when it comes to house prices, with recent research carried out by Zoopla showing that homes at ‘unlucky’ number 13 could be worth £3,900 less than neighbouring properties.

“Selling a house can be a complicated process, especially when it comes to trying to please potential buyers,” Kai Feller, co-founder of Bark.com, said.

“However, there are several steps homeowners can take to add as much value to a property as possible. We’ve been monitoring the demand for our home improvement service providers and decided to do some research into the effect these services could have on house prices. Some of these changes are simple, such as thoroughly tidying bedrooms for example, but research has shown that they really do make a huge difference to potential buyers.”

He continued: “The resulting guide highlights the most common things that affect property value and we hope that it will be a useful reference for homeowners around the UK, potentially earning them thousands of pounds when they come to sell.”