The product offers a discounted interest rate to customers remortgaging a property with an Energy Efficiency Rating of A or B.
As part of the agreement, Legal & General Mortgage Club members will have exclusive access to two mortgage products from Dudley Building Society.
The lender has also made a series of rate reductions across selected 5-year fixes by up to 0.50%.
The society has also expanded its mortgage offering with the launch of a 3-year fixed-rate mortgage range at various LTV options, from 60% through to 95%, or 85% for remortgage.
The changes, which come into effect on Monday 19 July, include a new residential 2-year fix 90% loan-to-value (LTV) product with £0 fee and a new residential 2-year fix 95% LTV product with £495 fee.
For first-time buyers, NatWest has made cut rates by up to 20bps and 8bps on 2 and 5-year deals respectively.
These changes include purchase and remortgage products, and will come into effect on Friday 9 July 2021.
An additional 804 mortgage products came onto the market in June 2021, up 6.6% on the prior month, according to data from Twenty7Tec.
Launching tomorrow, and available for both purchase and remortgage, highlights of the revised range include an 85% LTV 2-year fix cut from 2.35% to 2.28%.
Coventry for intermediaries has reduced the rates on selected Offset mortgages by up to 36 basis points, with the changes applying to most loan-to-values (LTVs).