New eco-friendly social homes for rent in Denbighshire are to be heated by warmth stored 450 feet deep in rocks laid down 350 million years ago.
The first new homes built by the Council in Denbighshire for almost 30 years are being erected by Brenig Construction at Tan y Sgubor, off Henllan Street, in Denbigh, and will be among the ‘greenest’ in Wales.
The 22 properties will feature sophisticated insulation and heating drawn from deep underground where the limestone, dating from a time when the area was a warm tropical sea, is at a constant 12C.
Brenig have had nine boreholes drilled by Kensa Drilling, each between 400 and 450 feet deep but just a foot wide and housing pipes filled with a mix of water and anti-freeze feed heat exchangers which do the rest, raising that temperature to a perfect 22C in the houses with water heated to 60C.
Brenig Construction Director Bleddyn Jones said: “These 22 homes are being built to very sophisticated, energy-saving Passivhaus standards for Denbighshire County Council.
“It is a landmark scheme because these are the first homes to be built by Denbighshire council since the early 1990’s and so far it has gone very well and everything is on schedule for completion by next spring.
“The timber construction is being made off-site and assembled here but the roofs will be made on-site in Denbigh.
“It’s really good to be involved in an important project like this where everything is special and this is the third project we have had across North Wales to feature Passivhaus specifications.”
The drilling rig has been operated by the Bedfordshire-based ANTS Group but lead driller Stuart Evans is on familiar territory – he is from Llanfair DC, near Ruthin.
He said: “It takes about two to three days to drill down each shaft. We’re on limestone here and it’s gone fine.
“The temperature down there is about 12C all the time and the pipes feed up to the heat exchanger in each house.”
Brenig Construction will build 18 two-bedroom and 4 four-bedroom semi-detached houses on the site, all certified to the energy-efficient Passivhaus standard, and part of the Council’s target to provide 170 new council houses by the end of 2022.
The frames and walls will be made off site in North Wales by Creating Enterprise, a subsidiary of Cartrefi Conwy, using the Beattie Passive Build system and assembled on site.
As well as the ground-source heating system each property will also be fitted with a second source of green energy with solar panels on the roofs.
Funding for the project is from Denbighshire County Council and the Welsh Government’s Innovative Housing Programme.
Cllr Tony Thomas, the Council’s lead member for Housing and Communities, said: “The Council is delighted work is progressing on these new council homes, the first to be designed and built for the county in 30 years, and we are pleased to be working with our partners on this project.
“Ensuring there is housing available to meet the needs of Denbighshire residents is a priority under our Corporate Plan.
“These homes will help meet the housing needs of residents by providing quality homes that are affordable as well as offering the highest levels of insulation to reduce energy consumption and energy efficiency to minimise carbon emissions and reduce household bills.”
Brenig Construction Joint Managing Director Howard Vaughan said: “We are becoming specialists in the constriction of these advanced and highly sophisticated homes which use very little energy.
“This is the third Passivhaus scheme we are involved with and it is definitely the housing of the future with sophisticated insulation and advanced building techniques and materials to cut carbon use.
“They can reduce energy bills by a third and here much of that energy is being produced from renewable sources in homes that are modern, comfortable and pleasant to live in.”
The Brenig Construction Group, based in Mochdre, near Colwyn Bay, has announced a current order book bulging with £60 million of work including plans for 300 new homes in the next four years.