67 is a traditionally built 1960’s bungalow, cavity walls, suspended floors and tiled roof. Purchased in 2010 the property had gas central heating, old uPVC windows, minimal loft insulation.
Watch our Short Film of Chafeys Avenue Here:
67 Chafey’s Avenue also features on the National Self Build and Renovation Centre NSBRC website here. Congratulations to Alan!
WHOLE HOUSE VENTILATION AND HEAT RECOVERY SYSTEM
During the winter of 2010 problems occurred with mould forming in the unused bedroom and generally the air quality in the house was not good. Research into house ventilation led me to Whole House Ventilation and eventually to a unit from Villavent ( now Systemair) https://www.systemair.com
In a bungalow this was a straight forward job and within the capability of any good DIY-er. Unit installed VR 250 ECH/B. Now replaced with a VTR 150/ B. Purchased as a complete kit and installed in 2 days. The only maintenance required is an annual filter change, the units operation is automatic.
From the time it was switched on we noticed an improvement in air quality and sufferers of hay fever do well in the house.
CONSERVATORY
In early 2011 a south facing gable end conservatory was constructed and adds good solar gain and warmth in mid winter.
SOLAR PV.
November 2011 saw the installation of a 4 kw PV system by Dorset Energy Solutions https://www.dorsetenergysolutions.co.uk/ Our installation was the first they installed on both an east and west facing roof. This installation has exceeded the Governments figures for this type of installation.
In March 2020 we had the system upgraded and the bungalow reroofed. The original 4 kw system was relocated to the east facing roof and a new 5.2 kw system installed in the west facing roof. In addition to this new array a 8.2 kw battery was installed to store our surplus PV generation for use later in the day. https://www.givenergy.co.uk/
The house is now at the maximum potential export level our electricity supplier will permit (around 8 kw). Both arrays are now “in roof”.
September 2022 another 8.2KW battery was added to the system giving us 16.4 KW.
June 2024 a 3rd 8.2 KW battery added, the system is now 24.6 KW.
INSULATION
Cavity wall insulation has been installed.
The loft originally had just 75 mm of insulation this is now nearer 500 mm.
The suspended ground floor has been insulated using 100 mm of Celotex. This was a major job involving the removal of the flooring. Not for the faint hearted.
2024. 90 mm of external wall insulation installed on the east, north and west elevations of the bungalow. This work has more than halved our heat loss through these walls and also given the building a facelift.
Work was undertaken by a local contractor. https://www.swliquidscreed.co.uk/
WINDOWS
Changed to A++ windows supplied by Polar Glaze. https://www.polarglaze.com/
LIGHTING
LED lights are used through the house and have been upgraded as better lights have come available.
RAINWATER HARVESTING
All of our rainwater is collected in 2 x 1100 litre IBC’s and then pumped to supply garden watering and car cleaning. Future upgrade would be connection to the toilet for flushing.
TRANSPORT
Having owned a self charging hybrid 4 years ago we took the plunge and went for full EV in 2020. Three years on and now both our cars are EV’s.
The car charger was upgraded to a smart charge in September 2022. A Myenergi Zappi https://www.myenergi.com/ This charger enables us to use our surplus PV generation to charge the cars. The amount of charge varies depending on the available PV generation and demand from the house but on a good summer day a maximum charge of 7KW can be achieved
Locally we cycle using electric bikes.
WATER and SPACE HEATING
Over the previous 2 years I have been looking at the various ways we can heat the house and supply hot water. There are now a good number of systems available to replace a gas boiler and in the end we opted for an Air Source Heat Pump (ASHP). A Mitsubishi Ecodan 6 KW unit https://www.les.mitsubishielectric.co.uk/ has been installed https://www.evergreensw.co.uk/ along with a 220 litre hot water tank. The house became gas free in June 2024.
An ASHP works well with the 9 KW of PV and this means the house can be heated for “free” on the sunny days spring and autumn. Mid winter we do not generate enough power but are able to buy in using an off peak tariff and storing this in the 3 batteries for later use.
The EDDI solar diverter https://www.myenergi.com/ is connected to the water cylinder making the best use of our surplus power to heat the water.
THE FUTURE / PROJECT SUMMARY
June 2024 saw the end of the major house upgrades with the external wall insulation and ASHP install.
In September 2022 we achieved an EPC of A and now in June 2024 I do wonder what the rating is now, certainly a good few points above the 108 scored back then.
The retrofit has taken 12 years and is a sum of its various parts which can be taken as a whole or parts and applied to any house.
The major parts of this retrofit have been completed although I am sure we will undertake a few updates.
The video below was filmed in 2023 before the external wall insulation and ASHP.
If you wish to visit this exceptional house at times outside the open event please email Alan