Ecology Building Society has launched an updated C-Change sustainable homes scheme, offering interest rate discounts of up to 1.25% on mortgages for homes that meet recognised energy standards.

The mutual says the new scheme gives “pride of place” to homes built using the Passivhaus method – an internationally recognised standard for low energy buildings.

The C-Change sustainable homes discounts include the new EnerPHit standard, which has been developed for retrofits (energy efficient refurbishments) using Passivhaus principles.

The society has also increased its maximum loan-to-value on residential and shared ownership properties to 90%, to enable it to support more people to build, buy or renovate sustainably.

Paul Ellis, Ecology chief executive, said: “Our C-Change sustainable homes discounts have shown that mortgage lenders have a vital role to play in improving the energy efficiency of our homes. Five years since we first launched this scheme, the challenges of cutting the carbon footprint of our housing stock are even clearer, and it’s the right time for us to acknowledge the proven effectiveness of the Passivhaus and EnerPHit standards in achieving warm, comfortable, healthy homes that are affordable to heat.”

Chris Herring, Ddirector of Green Building Store and chair of the Passivhaus Trust, added: “We congratulate Ecology Building Society for this forward-thinking and progressive step. By giving buildings built to Passivhaus and EnerPHit standards their highest level of mortgage discount, they will help support the development of genuine low energy construction in the UK.

“C-Change sustainable homes also offers discounts for properties achieving an Energy Performance Certificate (EPC) rating of B or above, EcoHomes Very Good or Excellent, Code for Sustainable Homes Level 4 and above, and AECB Silver and Gold.”