LOCATED amid the traditional red-brick streets of The Meadows, the home that Julian Marsh built for himself and his wife Judy will always turn heads.

Despite the high wooden wall surrounding the garden at the front, the Marsh's property attracts upwards glances because of its matt black roof, solar panels and large areas of glazing.

Inside, high-quality touches and quirky eco-design features confirm that this is probably the kind of house you would expect an architect with green credentials to build for himself.

But the low-energy bills enjoyed by Julian and Judy underlines that their home, called the Meat Factory because of its former use, also makes a serious statement about the financial benefits of green architecture.

Rainwater harvesting (they use filtered rainwater for everything apart from drinking) means their half-year water bill was £13 and the last summer bill was £50.

"And most of that was standing charges," said Julian. High insulation levels and use of solar panels for electricity and water heating mean the couple are actually in credit on their power bills.

Yet Julian is the first to admit that his home, which took four years to build, should be seen as an experiment in green materials and design – although an experiment which, so far, appears to have positive results.

"I need to find out what works so that I can build houses for other people," he said. Amid spiralling energy prices, more people could be learning valuable lessons from Julian and Judy's experiment.

Until now, houses like the Meat Factory have usually been seen as one-off showcases of sustainable design – interesting, but beyond the reach of most people because mainstream house-builders aren't building new homes with green design and technologies as standard.

Yet today, in Notts, sustainable design is finally beginning to have a visible impact on the built environment.

Last summer, a development of 38 new town houses in Green Street, The Meadows – all with solar panels on the roofs and designed to be ultra air-tight to minimise heat loss – went on the market. All snapped up within a few months.

Many were bought before they were even built. The Green Street developer, Nottingham-based regeneration specialist Blueprint, now wants to build a new development of 36 low-energy private sector townhouses in Carlton Road.

A planning application for this site, next to a former Co-op store, will be submitted in late summer. Blueprint chief executive Nick Ebbs told the Post: "The success of Green Street in The Meadows taught us that there is a demand for housing that is environmentally responsible and has a modern aesthetic.

"Buyers are motivated by their back pocket and the environmental agenda.

"Five years ago energy issues in housing were seen as a fringe issue for tree-huggers. Now it's become part of the mainstream."

Mainstream house builders argue that they cannot afford to take risks by building eco-housing like this on a large scale because the additional costs of building to sustainable standards makes them too expensive for most buyers.

But in the village of Collingham, near Newark, local house builder Gusto Homes is currently planning to build Nottinghamshire's largest development of 200 private sector "green" homes.

Houses in the £35m Braemar Farm development will have solar, high insulation and rainwater harvesting as standard.

Gusto's chief executive, Steff Wright, believes his additional development costs can be justified over the long-term if Gusto creates a community energy company that will own the homes' solar and rainwater kit.

The company would receive payment from the Government for the energy through the Feed-in Tariffs subsidy scheme over at least 20 years, enabling Gusto to sell discounted electricity to the homeowners and keep house price down.

Green technologies are also beginning to affect public sector housing. In The Meadows 55 traditional red-brick homes have been fitted with roof solar panels in a scheme managed by a community energy company.

In Aspley, Nottingham City Council has agreed a deal with E.on for the utility company to install and manage solar panels on 600 council homes, saving tenants around £100 per year on their bills.

Critics points out that fitting green technology to traditional, draughty British houses is a long way from a policy of building homes that are designed to minimise energy use in the first place.

But the local authority argues that solar energy is both helping the city meet its carbon reduction targets and addresses 'fuel poverty' in poorer areas.

In business, designing green features into new offices and business parks is becoming increasingly common place.

In the city centre, to the south of Canal Street in the Southside zone, a cluster of new private sector office developments are in the planning pipeline which aspire to high green credentials. These include Peel Group's 45,000sq ft Unity Square office and hotel development at Sovereign House, opposite Midland Station, and a digital business centre called The Portal, in Queen's Drive.

Both developments aspire to a standard called BREEAM (Building Research Establishment Environmental Assessment Method) which has become the Holy Grail of green standards and involves minimising energy and resources use during the construction and operation of buildings.

Across the city, E.on is also aiming for a rating of BREEAM Excellent at the new nine-storey office building it is developing at the Guildhall site.

Developer Miller Birch, which is working with city architects Maber, claims the new building will be "the greenest building ever constructed in Nottingham" and will incorporate sustainable design principles when it is complete in early 2012.

At the University of Nottingham, architects from Maber are also designing the new Energy Technologies Building, which aims to achieve an even higher standard – BREAAM Outstanding.

This £6m development, at the Innovation Park on the Jubilee Campus, will incorporate cooling via earth ducts and maximise use of renewable energy. On the NG2 business park, Speedo's new head office boasts "intelligent lighting" and roof-mounted solar to provide 20 per cent of the 43,000 sq ft building's electricity.

Any alien observers landing in Nottingham might be forgiven for thinking that developers were locked in a game of green one-upmanship. But Craig Straw, director of commercial property consultants InnesEngland, said: "What is behind this drive for sustainable design in business is a mixture of building regulations about energy use and carbon reduction, European directives on energy performance and businesses' commitment to their 'corporate social responsibility' agenda.

"There's little sign that sustainable design is adding anything to rental premiums at the moment, but what it's doing is giving a competitive advantage to you as a developer because green design is becoming a prerequisite of new commercial buildings."

At the visually striking £50m No.1 Nottingham Science Park, off University Boulevard, where green technologies include a wood-chip boiler that resembles a large spotted blancmange, developer Blueprint has always argued that the additional development costs were justified because the building would attract new "green-tech" companies that desired the kudos of an address that suited their image.

Today, that development gamble has paid off since the science park is now almost full, with prestige tenants including one of China's biggest car makers, Changan, which is developing a new generation of electric and hybrid vehicle engines.

However, the problem with building shiny new green buildings is that it leaves a lot of unwanted, "non-green" office space behind.

And Innes England calculates that there is 800,000 sq ft of space like this in and around the city centre.