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Wales adopts super-insulated, timber design for social housing

Western Solar
Photo: Western Solar

HOUSING INNOVATION: New housing designs in Wales use locally grown timber frames and cladding, together with high levels of insulation made from recycled newspaper – a combination that locks up atmospheric carbon in the building form.


The challenge of affordable housing is a global problem. In Wales, Western Solar has completed three innovative housing projects using its Ty Solar low-energy design. This was pioneered at Wales’ first solar village in Glanrhyd, Pembrokeshire, that we described in 2017

A $170 million Innovative Housing Programme is funding a range of projects to develop new solutions to the climate crisis and the urgent need for affordable and public housing.

To address these crises the government has also created a Public Sector Land Division to fast track the sustainable development of public sector land, especially to increase the delivery of more social housing. 

Passive house style low carbon homes

The Western Solar design features the use of passive house principles (although not Passivhaus certification) combined with locally grown timber frames and cladding, together with high levels of insulation made from recycled newspaper. This combination locks up atmospheric carbon in the building form.

The supply chain is very short, using local labour to assemble the frames in a nearby workshop, further reducing the carbon footprint. They are assembled on site in three days.

Animation of the construction of a Ty Solar home by Pentre Solar

The homes also sport solar PV panels on the roof, and batteries, providing the remaining heating requirements and much of the electrical power, and so they are low cost, low carbon homes to live in. They use around 12 per cent of the energy of a traditional home.

In a recent carbon audit by Wood Knowledge Wales, the Ty Solar house was shown to avoid 70,000 tonnes of CO2 over a 60-year life cycle when compared with traditional masonry construction. Pentre Solar’s residents have reported high levels of satisfaction with their homes.

Three sustainable projects

The three recent projects, all delivering social housing, are:

  • six highly energy-efficient dwellings on land at Clos yr Haul, Wind Street, Ammanford, delivered with Coastal Housing Group, on a former garage site that had been vacant for some years;
  • four homes at Bro Heulog at Trefin, Pembrokeshire;
  • a small hamlet near Square and Compass in North Pembrokeshire, with Pembrokeshire Housing Association.

Western Solar also plans to develop a 15-home scheme at Boncath, with 10 of the homes being affordable homes for families. The aim at Boncath is to create a garden village with all the homes benefiting from shared garden space as well as their own private spaces.

These homes will produce twice the amount of electricity they consume, and have electric car charging points, 10kWh battery storage and be fully three-phase enabled.

“Our homes have the lowest carbon footprint commercially available today,” says Western Solar’s founder/director Glen Peters.

“This development will include 6 apartments for the over-55s who want to downsize to a smaller house before their retirement age. They will have 75m2 with a target affordable rent of £80 per week,” says Peters.

At the time of writing, “it is to be owned by a Community Land Trust being specifically set up for it to hold the lease, and ATEB will administer it on its behalf,” says Peters. ATEB is a not-for-profit housing association.

Locally made homes

All of Western Solar’s homes are made in a small factory near Glanrhyd, Pembrokeshire.

“We’re using the same workforce that built Pentre Solar and taking on more apprentices. We have four apprentices, and six carpenters,” continues Peters.

An Innovative Housing project for 32 new affordable homes was going to happen in Burry Port, Carmarthenshire, on behalf of Croeso Cartrefi. However, Carmarthenshire County Council has decided to manage the project itself to a modified design. Western Solar is in dispute with the council to recover the substantial costs incurred in the design and planning consent.

New projects

“We get lots of enquiries, from the third sector and private sector, people who see sustainability as an important part of their offer,” continues Peters. “We’re also going to test five detached houses on the open market in 2020. We have already bought the land. We want to see how much the private sector is prepared to pay for sustainable housing. Is a wooden house attractive to private individuals?”

I reminded him that when we last spoke, he was more interested in working for the social sector rather than the private sector. 

“Yes, that had been the policy but we’ve been disappointed by the reaction of the public sector, the local councils. At Pembrokeshire County Council, for example, we have been trying to make the case for the last three years without success.

“These homes will hopefully help to subsidise the social housing activities. We’re a very small organisation so we can’t take on a huge scale. We’ll initially sell them on a cost-neutral basis. If we do expand in the social sector it has to be in conjunction with other contractors.”

Design evolution

I asked Peters how the design had evolved since the first homes.

“Since then, there have been new building regulations regarding the installation of sprinklers in new homes. There are stipulations about the water pressure for these. Utilities and housing associations like ATEB are demanding that developers absorb these costs.

“Also, housing providers discourage local processing of sewage ecologically on-site. Instead, we have to pay for connection to the sewage system, which adds considerably to costs.

“On the good side, we have been successful at locally sourcing our timber. In Boncath, most of timber for our houses is being sourced from Calon yn Tyfu Cyf, just a mile and a half down the road.”

The best timber to use, especially for the exterior cladding that was used in the earlier homes, is larch because of the way it weathers.

“However, we have to switch to Douglas Fir because larch has become scarcer due to an epidemic of disease that has been killing the trees.

“The structural walls have to be certified and we buy from a mid-Wales supplier. In future, we will also have to use sustainable urban drainage (SUDS), which also affects the cost.” 

The number of houses that can be built in a plot can be cut by up to 60 per cent, which affects the cost per house.

Solar power 

Again, on the positive side, “We’re putting 3-phase power into all houses to get more from the grid connection. We can put 7.5kWe of PV on all homes and convert the generated electricity into 3-phase and store it in 10kWh batteries in each home. Therefore, we will use as much as possible on site.

“The batteries give us enough capacity to enable a home to run for days in the event of a power cut. What’s more, if the government introduces differential pricing in future for peak hours these will be essential to reduce costs for residents.”

The lithium ion batteries are stored outside the houses with fire protection in their own sheds with their own fire alarms.

Heating is by passive solar from the south facing windows and traditional resistance heaters for night-time winter usage. 

Peters says that about 3000 kWh is taken from the grid for a three-bedroom house over the course of a year. He anticipates this will be halved with the use of battery storage.

David Thorpe is the author of Passive Solar Architecture Pocket Reference,  Energy Management in Buildings and  Sustainable Home Refurbishment.

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