In December 2011, Studio Negri featured on RTE Television architecture show About the House.
Presenter Duncan Stewart, a leading avocate of sustainable architecture, followed a project to retrofit a house in Dundrum, Co. Dublin. The house had a building energy rating of G, but the owners required an A rating. The house was an 1940s bungalow in Dundrum, Co. Dublin with an inefficient heating system. Could it be done?
Building Efficiency and Heating Challenges:
- No insulation
- No central heating
- It had a G Building Energy Rating (BER). This is the lowest BER rating.
The house would have to be extensively remodelled. The kitchen, living and bedroom spaces would have to be radically changed and there would be an extension into the attic. The owners also wished to gain a BER A-Rating. The achievement of such would reduce the running costs of the house to one tenth of what they were.
There was going to be a lot to accomplish.
There were also other crucial challenges:
Challenge 1: Compromise between Attic Headroom and Top Quality Insulation
There was not enough space in attic to convert it into comfortable living space but instead there was an opportunity for a lot more storage space. In order to achieve optimum headroom and yet have high quality insulation a lot of compromise was required. Roofing felts do not typically breathe well so its necessary to leave a ventillation layer. The first solution considered was to remove the existing roof tiles, use external insulation, and then reuse the tiles. This proved to be much too costly and might also break planning regulations.
In the end, it was decided to highly insulate and airtight the floor space of the attic and make the attic space seperate from the thermal envelope of the rest of the house. The double height area of the house would have 270 mm of insulation.
Challenge 2: Compromise between short term investment and long term heating costs:
The owners had initially budgetted for 100mm of external insulation. The owners accepted that it was worth spending an additional 5% to have 150mm external insulation – and ultimately Studio Negri encouraged them to agree to 180mm of insulation.
But the extra insulation also created additional challenges. This is semi-detached house and it would mean a line of 300mm difference between the neighbour’s house and the retrofitted house. Also the restructuring of the gable eaves would be quite complex.
Both problems were solved. The eaves on the gable were managed by putting an additional channel of aluminium preventing any water over-hang happening
Challenge 3: A combi-boiler or solar panels?
The owners wanted a combi-boiler and solar panels. The combi-boiler provides instant hot water. But they discovered that combi-boilers do not work with solar panels. The combi-boiler was their priority, but without solar panels its unlikely the house could get an A-rating
After much research a solution was found: There is a system from Alpha that uses a solar panel in conjunction with a combi-boiler. The solar panel collectors feed into a buffer tank that directly heata the showers and hot taps, but if this water is not hot enough a thermostatic valve diverts the pre-heated water to the combi-boiler which boosts it to the required temperature.
The owners have got what they wanted. An A3 BER rated house and a house for life that will never have to remodelled again.
You can watch the show here on RTE Televison.
See more photos of the dundrum retrofit
RTE Television About the House: http://www.rte.ie/tv/aboutthehouse/2011_prog5.html , and this particular show can be seen at:http://www.rte.ie/player/#!v=1125557
Builder: Elia Cassandro, ARES Construction, Website: www.ares.ie
Windows: Grady Joinery, Website: www.gradyjoinery.com,
Kitchen: Per Ploug, Danish Kitchen Design, Website: www.danishkitchendesign.ie
Bathroom: Stephen Kelly, H&V Bathrooms & Tiles, Website: www.hvbathrooms.com
Floor: Alan Byrne, Website: www.brooksgroup.ie
BER Assessor: Ann-Marie Fallon (Graduate Architect & Passive House Designer), Email: firstname.lastname@example.org