Despite the impact of the credit crunch, green mortgages have not seen any change, according to Norwich and Peterborough.

The building society reports that it has not seen a difference in the market in recent months and does not expect that any other firms would disagree.

Alison Rolls, a spokesperson for the firm, explained that people who choose these ethical or sustainable mortgages do so because of their personal principles, which are unaffected by market conditions.

Green mortgage customers are not driven by interest rates, Ms Rolls added.

"The type of person who is likely to make an enquiry about a green mortgage and follow that through by taking one out has slightly different priorities," she said.

Mortgages.co.uk reports that these ethical loans are increasing in popularity, although only three lenders currently offer green mortgage packages.

According to the website, the providers often make contributions to environmental or social charities.

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