An architect-designed home in Foxrock is part of a contemporary twin set that capitalises on free heating tapped from rock 600 feet beneath the surface, writes Mark Keenan
STILLWATER House at Hainault Road in Foxrock is hot to the core and rocks when it comes to saving money. It taps free heat obtainable from deep down in the depths of the earth via a geothermal heating system and, in the process, saves joint owner Bernard O'Beirne and his family thousands in annual bills.
"Geothermal heating is a technology which works like a fridge in reverse," says O'Beirne, of Maloney O'Beirne Architects, who usually specialises in designing buildings and interiors for the disabled.
He designed Stillwater – along with its almost symmetrical twin next door – in 2005. Now his life and work circumstances have changed and he's selling up.
"The earth has a natural heat stored deep below the surface and you can tap into it by sinking a conductive probe down into the warmer depths, which heats a brine liquid, which in turn heats your home."
Geothermal technology has traditionally been expensive to install – it requires drilling to vast depths – in this case two shafts totalling 1,000ft were required.
However, because there is such dense granite bedrock in Dublin 18, O'Beirne only had to sink two boreholes rather than the normally required four for the twin homes.
"For each drilling we went down 570ft through the rock before we hit water, and this was perfect for the geothermal system." It seems Foxrock has the best hot rock.
For the punter utilising a geothermal system, it means massively slashed heating bills. Stillwater's have been cut by thousands compared to what it would cost to heat a house its size (3,000sqft) on a regular boiler system.
The only additional cost is that attached to running the electrical pump which brings the heat to the surface.
The end result is an additional cost on the electrical bill of about 20pc above average for the sake of heating a home all year round.
The geology of the 'hot rock' is also interesting given that much of the natural heat in the Earth's core has been stored in there since the original formation of the planet – caused by the natural radioactive decay of minerals.
Heat comes around the area of the tectonic plate boundaries where volcanic activity comes closest to the surface.
But there's even more to Stillwater's revolutionary heating system than that. The house also uses the steam from the bathroom and the showers to reheat itself via a heat exchange system – now becoming standard in many one-off homes.
"Just by living in our homes we generate plenty of usable energy which is most usually wasted," says the architect who has recently placed the Foxrock home on the market for €1.385m.
Stillwater was designed by O'Beirne in 2005 and completed in 2006, the same year he sold the identical home next door to help retrofund the overall dream home project.
"We acquired the site and knocked down a dormer bungalow that was vacant for 25 years to build it. But quite early on we realised that we would need additional income to finish our dream house just as we wanted it.
"So we decided to split the site and build two homes. It seemed like the best idea to build a mirror version next door so one would reflect the other."
Designed for the modern family, Stillwater uses glass to ensure that light flows through the property at all times of the day. It also means that the light generated inside the house at night also carries.
The house has a custom kitchen designed and manufactured in Italy by Valcucine. The worktops and splashes are in white Paloma stone, there's a five ring Smeg piano hob, Gutman extractor and a large capacity Miele oven.
There's a dining area, a sitting room with a 50-inch television concealed behind a remote picture lift, and a "dancing flame" gas fire.
There are four bedrooms and the master chamber has an en suite, a bath with a TV over it and a dressing room. The family bathroom has a Jacuzzi and outside the garden comes with an ornate pond.
Enquiries to Hunters on 01-2897840