Alliance & Leicester has said that for a three-bedroom, semi-detached home, following the carbon neutral route can be expensive, but added that such a switch could lead to big savings on bills in the long-run. Cavity wall insulation, loft insulation, double glazing, an energy-efficient boiler, a wind turbine and solar electricity are all methods of heading towards carbon neutrality proposed by the financial services provider.

At an estimated 5,000 pounds, solar electricity is by far the largest expense when it comes to making a home carbon neutral, with homeowner loans a possible method of raising the funds to pay for the installation of solar panels as well as the panels themselves. According to the Energy Saving Trust (EST), the switch could save around 200 pounds annually on electricity bills.

Wind turbines were the second most expensive environmentally-friendly method proposed, coming at a cost of 1,500 pounds. This outlay is before installation, suggesting homeowners could be advised to compare loans when considering how to pay for the switch to power produced this way. Double glazing - a more familiar way of saving energy for many homeowners - comes at an estimated 1,400 pounds.

"Becoming carbon neutral will not happen overnight. Nowadays more and more people are giving environmental considerations and their carbon footprints a higher priority. This includes trying to make their homes as energy efficiency as possible. There are lots of diverse ways homeowners can try and make their homes greener but it all depends on how much people want to spend," said Richard Al-Dabbagh, senior personal loans manager at Alliance & Leicester.

Cavity wall insulation and loft insulation - costed at 500 pounds and 370 pounds respectively by the EST - are both less expensive measures, but with the former cutting heating bills by around 15 per cent annually and the latter saving a further 110 pounds a year, these cheaper methods could have a greater cost-saving impact for homeowners looking to spend low rate loans wisely. Ross Stokes, editor of self-builders tips and advice magazine SelfBuild & Design, suggests it is worth getting the best possible insulation with your money. "Insulation is something that you have to put in anyway - so it's a good decision to put in the best that you can afford at the start," he said.

According to Alliance & Leicester, the best way for homeowners to spend secured loans when it comes to improving the energy efficiency of their house is by replacing an old boiler. The financial services provider said that according to figures from the EST, replacing boilers more than 15 years old could save some 240 pounds a year. At an estimated cost of 500 pounds, by the third year of having a new, energy efficient boiler it will have paid for itself.

At the beginning of November, insurer More Than revealed that three in five new homeowners were finding funding work on their new properties difficult due to the high cost of housing in Britain.