SuperHomes Case Study 3: Yvonne Doyle
Yvonne Doyle’s detached four-bedroom family home that she and her husband built near Templemore, Co. Tipperary, in 2004, was never warm enough in winter. The small sitting room with sun-room was off limits unless the fire was on, and the guest bedroom above was always cold. The house was draughty from a warped front-door, two open fireplaces, worn window seals and poorly sealed down-lighters. There was some dampness in the main bathroom and the small sitting room, as well as a build up of condensation. The original 200mm attic insulation was inconsistent. The 210 square metre two-storey timber frame with block work house had underfloor heating throughout fuelled by a standard oil boiler. “We were never achieving the heat that we expected,” says Yvonne. The building energy rating (BER) was C3.
Over the years Yvonne and her husband had talked about how to improve their house and their environmental footprint. “But we never really knew where to start or how to get good value for money,” she says. All this changed in September 2015 when she saw a SuperHomes promotion on twitter. “I immediately sent it to my husband and he got straight back to me saying: ‘This fits everything for us’.” Yvonne set the ball rolling and, after initial discussion, Tipperary Energy Agency, which administers the scheme, sent out an engineer to assess the house in detail.
Yvonne and her husband signed up to SuperHomes within a couple of weeks. “For us what really sold it was the knowledge that Tipperary Energy Agency had. We trusted them. Also the fact that they would manage the whole project.” “We went with every one of their recommendations,” says Yvonne.
• replacement of the oil boiler with an air source heat pump
• airtightness retrofit and test
• replacement of the existing front door with a low energy door
• installation and taping of fireproof covers for down-lighters to reduce draughts
• installation of demand controlled ventilation
• insulation of attic to a coverage of 300mm throughout
• replacement of the hot water tank with a 200l cylinder
• installation of wood burning stoves in place of both open fires
• a full window service
• replacement of all light fittings with LEDs
• removal of 24 down-lighters and replacement with a central light rossette.
A key part of SuperHomes is the replacement of fossil fuel heating systems with a renewable energy source. As a significant portion of the energy produced by air source heat pumps is considered renewable they are recommended for replacing oil boilers. Air source heat pumps use the same physics as a fridge. Heat is taken from the air but, instead of being vented off, for instance at the back of a fridge, it is used to heat the water that heats the house, in this case through the under floor heating. Yvonne’s oil-fuelled boiler was replaced by an 11.2kW outdoor Mitsubishi Ecodan air to water heat pump. A flow temperature controller that includes intelligent room temperature control was also installed. As part of the switch to an air source heat pump system the hot water tank was replaced with a larger cylinder with a low temperature coil. “We have constant hot water because the heat pump automatically tops it up. I haven’t touched an immersion switch since,” says Yvonne.
Despite all their windows being double-glazed with a low U-value, draughts had developed in some due to lack of maintenance. After a full window service as part of the SuperHomes retrofit these draughts were eliminated. The warped front door was also replaced with a new low energy door. Previously their “big square hallway” was always cold in winter. “Now you don’t know how cold it is until you go outside,” says Yvonne. Draughts from the attic were eliminated from around the upstairs down-lighters by the installation and taping of fireproof covers above each opening.
The closing of the two fireplaces in the large family room and the small sitting room and installation of wood stoves also contributed to the improved air tightness.
More useable space in winter
Since the SuperHomes retrofit Yvonne says her children, aged five and seven, use much more of the house throughout the year, including the hall, the small sitting room and the guest room. “In the past we would have closed the doors to these rooms. Now it’s 18 degrees upstairs and 20 degrees or warmer downstairs. “We light the stoves for ambience and three pieces of timber would send out enough heat.” The SuperHomes process was very simple, says Yvonne. “There was a little bit of paperwork. The disruption was minimal. If we had any queries the contractor was fantastic which was very reassuring. I have to say it was totally painless.” Once the works were completed (within a couple of months) Yvonne says: “We saw the benefits immediately. We had the most comfortable winter.”
The total cost of the bespoke retrofit was €26,500 including VAT, of which the grant was just under €8000. Prior to the SuperHomes retrofit Yvonne and her husband’s combined oil and solid fuel costs were approximately €2000. Yet the house wasn’t comfortable in winter.
Their electricity bill was €1000 per annum. Post retrofit, and with the new system in place for 12 months, the electricity bill has increased to €1756. “But we have no oil cost and we haven’t even made a dent in the €270 of logs that we bought.” This represents an annual financial saving for heating and lighting of over €1000. More recently Yvonne and her husband have installed 1.5kW of solar PV panels on their roof, bringing their BER to A3. Yvonne is delighted with her retrofitted home. “It’s wonderful,” she says.
You can apply for SuperHomes 2017 here