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Eco-renovation of 1998 Semi-detached Villa
Complete eco-renovation of an 1898 three-storey, five-bedroom, semi- detached Victorian villa, in Nottingham...

We embarked upon a comprehensive eco-renovation of our house, which we bought in 1998, with a view to becoming as autonomous as possible. To this end we tackled every aspect of our Victorian house's performance, including insulation, heating, waste and water. When first bought the property was a 'thermal nightmare'. There was no insulation and heating was provided by electric bar fires and an immersion water heater. Insulation thus emerged as our largest challenge. We had to insulate every external wall in the house but in doing so we managed to improve their thermal performance by 860%.

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The house was generally structurally sound, albeit in a very poor condition due to twenty years of student lets. Having lived on the experimental new build Hockerton Housing Project we decided we wanted to make the ‘philosophical and political’ case for addressing the existing housing stock – by taking on the most challenging house possible as a showcase for environmental renovation.

Vital Statistics

This property was built between 1700-1920. It is a semi-detached house with 5 bedrooms, located in an inner-city area in East Midlands The household is a multiple occupancy shared house, with an average occupancy of 3 all year round. No planning restrictions are in effect.

Annual Energy Use

(No energy use data is currently available for this ecovation.)

About us and why we did it

I'm Penney Poyzer and my partner is Gill Schalom. Gill is an architect specialising in environmental design and renovation. I used to work for Global Action Plan, and more recently have presented of BBC2's 'No Waste Like Home'.

We were inspired by the work and ideas of Robert and Brenda Vale, and having met (and fallen in love) on the Hockerton Housing Project, the UK's first group of zero CO2 houses, we decided to apply the lessons learnt from a rural new-build to an urban retrofit. We wished to disseminate our passion, experience and ideas as widely as possible, and provide a practical urban example of ecologically sustainable living. Given that the majority of people in the UK live in towns and cities, and that housing represents 30% of energy consumption and 30% of CO2 emissions, it seemed imperative to tackle the existing housing stock already locked into these patterns of energy consumption and pollution rather than solely to focus on new-builds. After all it makes environmental sense to recycle old houses rather than knock them down and start again.

So, we bought our house in Nottingham, in 1998, and began from there...

Our house is now sometimes opened for tours. For further information contact us, Penney and Gill, at

For further information there is a web-based guide to the house at msarchitects

Heating and Power

We opted for a wood burner to provide our heating, and for heating water during the summer we have a flat plate solar panel.

Our chosen wood burner is an imported Italian Mescoli wood burner, which transfers heat to a 1,100 litre heat store tank. As we were skeptical of the wood pellet burners we chose a model that can handle the small pieces of wood readily available as waste and trimmings. The total cost of the system was £5,000 of which £3,400 was met by grants. In summer all water heating is provided by a 4m2 flat plate solar panel.

Water and Sewage

Feeling that water conservation is of particular importance we sought out rigorous methods for harvesting rainwater and reusing any water we use. (Sometimes in eco-houses this can be rather neglected).

We installed two tanks in the cellar hold 2,000 litres of rainwater for flushing toilets, washing clothes and watering the garden. The toilets are a dual flush Swedish model that uses only 2 or 4 litres.

Sewage is separated in a low maintenance Aquatron centrifuge. The liquids drain into the sewer and the solids are deposited in a large composting chamber. This has not yet needed emptying in five years. Our plans for the future include recycling liquid sewage in a garden reed bed.

Tags: Grey Water, Water Conservation


To substantially improve the thermal performance of this 'heat leaking' house we opted for extensive insulation. The front street-facing walls were internally insulated while external insulation was applied to the side and rears walls.

Insulating every external wall in the house has (for obvious reasons) been our largest challenge. However as the thermal performance of the walls has been improved by a 860%, this undoubtedly was a necessary and extremely effective undertaking.

As is common in Victorian and Georgian buildings, the best quality bricks are on the walls facing the street. It was to maintain their appearance that we insulated these walls internally with plasterboard backed with 100mm of phenolic insulating foam. We took great care with detailing to reduce cold bridging- with careful fitting around corners and additional insulation at the base of walls.

The less attractive rear and side walls were insulated externally with 140mm of an eps foam insulation system supplied by Sto, and then rendered. The decision to use standard insulation materials was not an easy one but we eventually took it on the grounds of cost. It would have taken us so long to save the money for eco-insulation that we would have lost any of the benefits.

We have insulated the loft with 400 mm of Warmcel insulation made from recycled newspaper, giving an insulation value nearly four times greater than current building standards. We also insulated the floor over the cellar with 100mm of sheepswool between the joists held in place with fibreboard.

After much pondering, we decided to not replace the existing PVC double-glazing as it cannot be recycled. Instead, for the new windows we fitted timber frames holding triple glazing with a krypton gas fill.

Tags: Loft, Cavity, Solid Wall, Alternative Materials


We have used a very wide range of ecomaterials for our interior finish.

These include clay, reed and hessian as an alternative to plasterboard in the bathroom; eco paints using self-mix casein powder, or soya or citrus based emulsions; lino and sisal carpet on floors; and salvaged materials and furniture.

Obstacles and How we Overcame Them

Funding and the government's Clear Skies programme both proved to major problems.

The main obstacle was funding the project. We had to implement our plans in instalments as we saved the money to pay for it, and we found ourselves living for years in a semi-finished house.

We had a very positive experience of our dealings with our local authority (Ruchcliffe Borough Council), which was very supportive. However, we did have a major struggle with the government’s Clear Skies programme, which offers substantial grants for biofuel heating systems. The registered installer imposed by the scheme as a condition of funding recommended a boiler that was not recognized under the Clean Air Act. This meant we found ourselves fighting a test case which may well be the price we pay for 'being freaks'. We ultimately won because the local authority, which implements the clean air legislation, approved the wood burner. Clear Skies had clearly not given any thought to the policy details for implementation and had recommended an installer that was inexperienced in domestic installation of this kind of system.

Information Sources

Although we already have fairly extensive contacts with other eco-renovation specialists and pioneers we still found we had to do a great deal of research.

We found the Green Shop and Construction Resources were a great help for advising on materials, and would recommend the Autonomous House by Robert and Brenda Vale as theoretical reading, ( There was a very limited range of products available in the UK, almost all of which were imported from Germany, Sweden or the Netherlands, when we embarked upon our eco-renovation. The product range however has increased dramatically during the past few years.

Low Carbon Lifestyle

So, what were the improvements in energy performance or the carbon savings?

Before the changes, all space and water heating was electrical. If supplied from conventional grid electricity this would have represented very high emissions of nearly 19 tonnes of CO2/year. Improved insulation and air tightness halved the heating load. Once the solar and wood heating is factored in, the house energy emissions fell to 2.9 tonnes CO2/year, an 85% fall in emissions.

Top Tips

Finding the builders and getting a big house...

1. Finding the builders. The Association for Environmentally Conscious Building is a good source of specialist builders. Sustainable Energy Action in London runs a ‘green register’ of construction professionals who have attended its two-day intensive course in environmental building. It is an excellent place to find people who understand the basics and have the interest and commitment to do a good job. Failing this, we recommend another course of action – finding an inexperienced but willing ‘jobbing builder’ who was happy to be trained by us on the job.

2. Get a big house. We found that it made sense to buy a large house so that we could live in one part of the house whilst work is carried out in another and, once refurbished, generate a long-term income from lodgers.

© Climate Outreach Information Network, 2006-2007
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