A building society founded in a tiny upstairs office at Cross Hills three decades ago has announced record results.

The Ecology – which began with just £5,000 in 1981 – last year achieved assets of £124.8 million, up by £15 million on the previous year.

Gross lending reached an unprecedented £18.4 million – up from £14.3 million in 2012 – with net lending passing the £10 million milestone for the first time.

There was a net profit of £402,000 and a rise in savings balances to £116.6 million.

Paul Ellis – who has been chief executive of the society, now based in a ‘green’ headquarters building at Silsden, since 1995 – said: “Ten years ago the Ecology’s approach was seen as well-meaning idealism – fine for the hippies, but of no relevance to the wider financial sector.

“Today, voices across the political spectrum call for better banking that puts long-term value and social usefulness at the fore.

“Some have called this boring banking. We think it’s the most exciting type of finance there could be – using money to make a positive difference for people and planet. Our results prove the commercial viability of genuinely sustainable finance. Is there now any excuse for the big banks not to put ethics at the heart of their work?”

Since his appointment, Mr Ellis has overseen an asset increase of more than £100m.

Last year, 83 per cent of mortgages were advanced on residential properties – including new builds, conversions and renovations – and the remainder on developments for organisations including charities, housing co-operatives and community businesses.

The Ecology Building Society was born at a Green Party conference when a solicitor complained about difficulties he had encountered finding a mortgage for a property needing extensive renovation.

He and nine others each put in £500, and in 1981 trading began.

By 1985, there were over 1,000 investors and the society had assets totalling £1.25m.

In 2011, assets broke through the £100m mark.

“Many things have changed since 1981 but our mission and principles haven’t,” said Mr Ellis.

“We’re dedicated to building a greener society and this shapes every decision we make.”