Barclays has introduced a range of new 'green' mortgages, offering cheaper rates to homebuyers who purchase an energy-efficient new-build home.
The deals are available to first-time buyers and home movers, and special products are available for those using the Help to Buy scheme.
Here, we explain how the new deals work and investigate whether they offer the best mortgage rates out there.
Barclays claims that this means a saving of £750 on a £150,000 loan over a five-year fixed-rate period.
On top of this, the lender cites Carbon Trust data showing that someone living in a three-bedroom home with an EPC rating of B would spend £585 less on energy bills than if they lived in an equivalent E-rated property - meaning a total potentialtotal saving of £1,335.
To be eligible for a green mortgage, you'll need to purchase a new-build home with a predicted Energy Performance Certificate (EPC) rating of A or B.
As it's impossible to provide an EPC rating for a property that hasn't yet been built, the housebuilders will instead provide a Predicted Energy Assessment (PEA) before the home is built.
If you buy a property through one of the five developers partnered with Barclays, they will provide the PEA to the lender, who will use this to confirm your mortgage agreement.
The offer is initially only open to those who purchase from five housebuilders - Barratt, Berkeley, Countryside, Crest Nicholson and Redrow - though Barclays says it intends to partner with other major housebuilders by the end of 2018.
|Type of deal||Product name||Initial rate||Revert rate||APRC||Fees||Max loan-to-value|
|Two-year fixed||Barclays Green Home 2 Year Fixed||1.84%||3.99%*||3.7%||£999||90%|
|Five-year fixed||Barclays Green Home 5 Year Fixed||2.34%||3.99%*||3.4%||£999||90%|
|Two-year fixed||Barclays Green Home 2 Year Fixed Help to Buy: Equity Loan Scheme||1.50%||3.99%*||3.6%||£749||75%|
|Five-year fixed||Barclays Green Home 5 Year Fixed Help to Buy: Equity Loan Scheme||2.05%||3.99%*||3.3%||£749||75%|
* Revert rate based on 3.49% + Bank of England base rate (currently 0.5%)
But how do they compare to other products on the market?
If you're using Help to Buy and have an LTV of 75%, the five-year Barclays green deal is the cheapest mortgage on the market, according to Moneyfacts.
The Barclays Green Home five-year rate for buyers with a 90% LTV is joint-cheapest with Platform, which also offers a 2.34% initial rate (although Platform has a revert rate of 4.74% and pricier fees at £1,499).
However, Barclays' two-year green deals aren't current market leaders. For borrowers with a 90% LTV, Yorkshire Bank is offering a two-year fixed rate of 1.79% (revert-to rate 4.99%, fees £1,495).
For those using a Help to Buy equity loan with a 75% LTV, the best two-year fixed rate comes from Santander, which is offering an introductory rate of 1.49% (revert-to rate 3.75%, £999 fee).
When properties are sold they must have a valid Energy Performance Certificate, or EPC as it's commonly known.
This certificate explains how energy-efficient a property is, and provides an overall rating between A (most efficient) and G (least efficient).
In 2017, around 80% of new-build properties were granted EPC ratings of A or B.
The new Barclays deals are only available on new-build properties - but is a new-build home the right option for you?
While new-builds have plenty in their favour - not least their energy efficiency - they can also come with problems, such as build delays and snagging issues, and in some cases cost significantly more than older properties of the same size.