Ethical investment has gradually become accepted by all but the most cynical of City fund managers, thanks largely to the pioneering efforts of the Co-op Bank.
Now the growing "green" sector within the personal finance industry has a new product on offer - mortgages for those whose applications are deemed ecologically-friendly.
Housebuyers who agree to install energy-saving systems will be high on the list. Unsurprisingly, the building society specialising in these loans is called the Ecology.
The organisation was founded in 1981 in the small Yorkshire town of Cross Hills, near Keighley.
In that Thatcherite decade, the rural backwater was an appropriate place for the Ecology. Advocating that housebuyers should focus on environmental and energy-saving improvements certainly was not in sync with the mood of the times.
Few owners were concerned about anything more than double-figure growth in the value of their property.
Now though, the philosophy is different. Each of the last five years has seen
the Ecology rated the UK's fastest-growing society.
Its members are spread across the country and into Northern Ireland. Assets have passed the pounds 25 million mark, of which mortgage assets are approaching pounds 20 million.
Admittedly, the Ecology is still one of the mutual movement's minnows, with just under 600 borrowers and just over 6,000 savers.
However, chief executive Mr Paul Ellis is understandably bullish.
"We continue to grow, expanding our business activities and product range.
"We are looking forward to the future development of the society and the continued support of the membership, who make the Ecology what it is," he says.
The Ecology has recently developed "buy to let" mortgages, is now able to lend to corporate bodies, and has removed restrictions on loans to housing co-operatives.
Despite the addition of niche products, however, most loans still go to two groups of borrowers.
Mr Ellis said: "The majority of loans are for derelict properties, farm houses, Victorian terraces, or older buildings requiring major renovation.
"These often go to people who are attracted to redundant buildings and one of our key aims is to recycle the building stock."
The second category is loans for ultra-green people, who wish to create properties that will have a very positive impact on the environment. …