Homeowners could be paying up to 50% more for their gas and electricity bills if their property has a poor energy rating.
Every home rented, sold or purchased since 2008 has an energy performance certificate (EPC) that is valid for ten years.
An EPC shows you how energy efficient your home is, with a rating from Grade A to Grade G.
If your home is rated Grade A, then it is considered the most energy efficient, while homes rated Grade G are the worst.
Experts at Zoopla say the difference in how much your energy bills cost could be as much as 52% between the most and least efficient properties.
Alex Rose, Director of New Homes at Zoopla, said: “Last year, some 84% of new homes had an EPC rating of B or higher, in comparison to 3% of existing homes across the country.
“Our analysis of EPC data shows that on average, homebuyers who purchased a new build house last year saved an average of 52% on their annual energy costs in comparison to a second-hand house.
Did you look at the EPC rating of your property before buying it? Let us know in the comments below.
“Government policy is also driving the green agenda, with the introduction of the ban on gas boilers for new homes from 2025 creating more awareness amongst buyers around energy efficiency and the environmental benefits of new builds.”
Here are some the cheapest homes on the market right now with the best energy ratings.
It's worth noting that even older properties can be upgraded to the best energy rating, but it will likely cost you thousands of pounds.
It will, however, lower your energy bills in the long run.
Two-bedroom bungalow in Merseyside - £120,000
This eco-friendly semi-detached bungalow was awarded a Grade A on the EPC due to having solar panels installed.
The estate agents Reeds Rains say this property is positioned "in a quiet cul-de-sac location" meaning it is perfect for a family of older homeowners.
Two-bedroom house in Yorkshire - £125,000
This two-bed end of terrace house in Bridlington also has a Grade A EPC rating, meaning it is considered very energy efficient.
It has a UPVC front door and is UPVC double glazed throughout to keep in the warmth.
Three-bedroom house in Yorkshire - £140,000
You'll notice this three-bed home in South Yorkshire also has solar panels, giving it a Grade A EPC rating.
Upstairs are three generous bedrooms - two with fitted wardrobes - and a stunning shower room with double size shower cubicle.
Three-bedroom house in Yorkshire - £145,000
This three bedroom semi detached property in Rotherham comes with a conservatory to the rear and off road parking.
Also with a Grade A EPC rating, it is double glazed throughout and has a low maintenance garden.