Affordable homes in Devon development require no heating
An affordable housing scheme in Exeter has exceeded expectations for being environmentally friendly.
The development, which was designed to use a combination of natural materials and sustainable technology, was built to passive house standard and it turns out that residents are saving even more than expected on their energy bills.
In fact, some households never have to turn their heating on at all. The level of thermal insulation in the homes is so good that residual heat from people, lighting and other devices is enough to keep the homes cosy on even the coldest winter days.
Passive House Plus reports that when Exeter City Council decided to build the Knights Place development in 2010, it was a "brave move". The local authority hadn't built anything in two decades and the project was set to be among the earliest and largest passive house developments in the UK.
The two blocks comprised 18 one- and two-bedroom flats and cost £2.1 million. Features of the homes included:
- 250mm of thermal wall insulation
- Clay roof tiles
- Roof insulation with vapour check and air tightness layer
- Concrete floor slabs and floor insulation
- Triple-glazed windows and doors
- Electrical duct heating
- Solar thermal water heating
- Ventilation and heat recovery system
In addition, all timber was FSC certified, while ceramic roofing. Floor and wall tiles were all locally produced, natural or mineral paints were used throughout the properties, all light fittings were energy efficient and water-saving methods were used.
Commenting on the project, Emma Osmundsen, housing development manager at Exeter City Council, explained that the new homes were primarily for people over the age of 55 - and that was one of the reasons the passive house design was originally chosen.
"We were acutely aware of fuel poverty issues and we were also very keen to build homes that promoted the health of our tenants. So we felt that the passive house standard was a good starting point," she said.
In 2012, the development won the Eco Building of the Year Award, and this justified the council's decision for sustainable housing. However, the council also wanted data on the project, which would help them to make future decisions about specifications for new housing in the region.
So, the council engaged their tenants and monitored the energy performance of the buildings. The research provided information about how residents lived in the properties and helped the council to set a high benchmark for new housing in the city.
It also gave them an opportunity to improve the efficiency of the homes even more. Since none of the tenants had ever lived in a passive house before, this gave them the chance to make the most of the low-energy features.
Ms Osmundsen explained: "Every season, we would visit all of the tenants and take them through what to expect in that season in terms of how best to use their home. Because some of the tenants are older, quite often we would see them on a one-to-one basis."
She noted that in the beginning there were "psychological issues" that the tenants had to overcome. Since there are no conventional heating systems the tenants couldn't see fires or radiators, so they reported feeling cold, even though the temperature sensors indicated comfortable temperatures.
Despite a few hiccups and some, overall tenant feedback for the passive houses was positive. In nine out of the 18 units, occupants reported that they haven't used the heating - and the monitoring period covered one of the coldest winters on record.
Thomas Gartner, lead architect on the project, says the first floor and ground floor units are the best protected and are the ones that aren't using the heating. He added that the units on the perimeters are using small amounts of energy.