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Renovated 1920's Semi deatched house

The House

Our house is a 1926 semi-detached house of a very familiar type seen throughout Britain. It has cavity walls constructed of clinker blocks. We moved into the house in 1989 and it was then in need of general refurbishment. 

Our first steps were to update the bathroom, and restore the kitchen using the original units. With our household comprising two adults and three children, and our house being of a very familiar housing type, we hope our experience shows what can be done readily and effectively through the implementation of existing measures for all houses of this age.

With a growing family we constructed a large extension and sought to conserve heat and reduce energy usage through a series of renovations, which included double-glazing the existing porch at the front of the house and adding a small unheated conservatory to the rear of the house to act as both sun trap and draught lobby.
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Vital Statistics

This property was built between 1920-1960. It is a semi-detached house with 4 bedrooms, located in a suburban area in Wales.The household is parent(s) with children, with an average occupancy of 5 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

We are Derek and Tracey Cozens. We live in Barry with our three children. 

We do value the modern lifestyle, we like living in the centre of a town and Derek loves cars, especially a prized 1950’s Bentley. However, we are also concerned about waste and environmental issues and became involved in local recycling schemes. From there we found ourselves as the ‘poster family’ for the local council, and through this have become enthused about promoting green lifestyles.

Heating and Power

We installed a condensing boiler, doubled the capacity of our radiators and deployed insulating foil and TRVs.

We used an A rated Feroli condensing gas boiler, and doubled the capacity of the radiators. Insulating foil has been placed behind all radiators with Thermostatic Radiator Valves (TRVs) fitted throughout. We also have the capacity for additional space heating which is provided by an ‘art deco’ wood burner. It runs on waste wood and friends and neighbours leave wood for us on our drive.

Power Generation

We have opted for wind power generation, and possibly PV arrays, to reduce our consumption of fossil fuels.

As Barry is a seaside town with strong winds and ideal for domestic wind generation. Our house will shortly be one of the first in Britain to be fitted with a Windsave “plug and play” wind generator. The company has already used a picture of our house in their publicity. We are considering installing PV as a further project.


Through double-glazing and multiple forms of insulation we have endeavoured to cut down the amount of heat that escapes from our house.

The original leaded windows were all replaced with new double glazed units.

Through a council scheme we installed 270mm of glass fibre over the 60mm of mica granules already in the loft. All cavities in the orginal house were insulated with injected foam, and the cavities in the extension was insulated to current building regulations. Insulation has also been installed above the ceiling of the bay window, all around the bath (inside the casing), and all accessible pipes have been similarly insulated. 


From light bulbs through ventilator fans to Sava plugs we have adopted as many small scale (but fairly high impact) methods of reducing our consumption of energy.

All light bulbs are low energy compact fluorescents. There are heat exchanging ventilator fans in the kitchen and bathroom. Sava Plugs are fitted on the chest freezer and fridge freezer

With three kids we always have clothes to dry. In winter we hang clothes in the utility room on a “kitchen maid” and run a dehumidifier fan on slow speed. This uses far less power than an electric clothes drier, and is gentler on the clothes too. 


To accommodate our growing family we built a large extension along the side of the house.

This extension more than doubled the floor area of the house. We realised that the heating bills could increase substantially as a result and this spurred us to seek environmentally-focused efficiency improvements in all areas. We thus double-glazed the existing porch at the front of the house and added a small unheated conservatory to the rear of the house, accessed through the double patio doors that originally led into the garden. The conservatory functions as a draught lobby and sun trap.

Obstacles and How we Overcame Them

Our intention to install a wind generator proved to be the most contentious issue.

Although the wind turbine had been granted planning approval by the Glamorgan Borough Council it faced initial objection from the Barry Town Council, which has the power to challenge planning decisions, who feared it might set a precedent - which, of course, is the whole point! The installation of the wind generator has been long delayed and prices have been increased to cover the cost of bringing installers down from Scotland - these are perhaps some of the perils of being a 'pioneer'. 

Otherwise the problems we have faced have been those common to building projects in general: delays and some issues with installers.

Information Sources

Researching, networking and talking to experts have been key to enabling our eco-renovation.

We spent a lot of time researching on the web and talking to experts including the Centre for Alternative Technology. We have now built a particularly close and valuable relationship with the council’s energy officer, promoting the council's schemes and receiving advice and some funding in return.

Building work continued through 2005, during which time energy consumption rose, as is usual during building work. It will be at least a year before the full performance of the changes can be known and of course allowance will need to be made for the sizeable expansion of the size of the house and its high level of occupancy. The local authority energy officer is monitoring energy use. We are not intending to sit on our laurels though and are already planning another wave of energy saving ideas.

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Top Tips

Make it a family affair, be in control and be pro-active.

- Switch it off with your fingers! Every day is different and you can’t predict energy use, so it makes best sense to control your own system. We always turn off lights when we leave the room and turn off all heating when the family leaves the house.
- Be pro-active when looking for funding. We have very actively pursued every grant, subsidy and discount we can, offering to use our 'pioneer status' to strongly promote the products.
- Involve your kids. If you have children, eco-renovation can be very educational for them. They learn a lot and acquire new values.

© Climate Outreach Information Network, 2006-2007
Design - AHG