Developer James Kearney has chosen a site in Headford Co. Galway to construct a house which showcases a range of sustainable technologies. Standing on three-quarters of an acre, the house has been built to exceed current and future building regulations by some distance, yet retain a traditional look and achieve its ends using locally available products and expertise.
With a total usable floor area of 372 square metres including the basement, the house features a rainwater harvesting system, solar water heating, a wood pellet stove, wind turbine and photovoltaic electricity generation, a heat exchanger as well as a high insulation spec. Built with the technical guidance of Peter Keavney of Galway Energy Agency, the house, says Keavney, is special because it’s not so special. “There’s nothing unusual about this house…Yes it has a basement, but it’s still a typical two storey house in the countryside, but what we’re doing is introducing insulation and heating products that are available cost effectively at the local level. The point we’re making is because it’s cost effective and available locally, the opportunity and the potential for replicating this is immense.”
Under the European Water Framework Directive, domestic water charges are set to be re-introduced into Ireland within the next four years (and are tipped to be introduced after the General Election next year—Ed.). With this in mind, Kearney took the decision to design and install his own rainwater harvesting system. The water is collected in the usual way from the roof, then channelled via filter into a tank in the garage. “This is the primary tank.” Kearney explains. “The water in that will be used for toilets and any overflow from that will go into an overflow tank which is outside and which can be used for any outside use.” Approximately 50% of the water used in any domestic setting goes on things like watering the garden, washing the car and flushing the toilets and so does not need to be potable. Using the clean water available on the roof, household water consumption (and future bills) can be drastically reduced.
A series of Solar Panels provided by Nivektron in Spiddal looks after the home's hot water requirements
Inside the house, the first thing to consider was the insulation. In the walls, a wider cavity – 150mm – is pump filled with a platinum polystyrene bead. On the floor, there’s 100mm of polyiso, while the roof is insulated with 300mm of Warmcell cellulose fibre. Ecobead in Oranmore supplied and fitted all the insulation which delivers a U value of 0.2 for the walls, 0.13 for the roof and 0.18 for the floor. “If you take the walls, the outside value for building regulations is 0.37.” says Peter Keavney. “It’s similar for the floor and it’s actually 0.25 for the roof, so we’ve halved values basically, plus we’ve put in a product that’s available here in Galway that’s actually cheaper than fibre glass. Also, the contractor that’s installing the roof insulation is the same one that’s doing the walls so therefore he was in a position to buy the floor insulation and offer an overall insulation package to the contractor.” A supply and fit contract has the advantage of ensuring a better insulation performance through the use of qualified installation technicians, plus using one contractor for the entire spec offers a more cost effective solution.
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