Tre Ifan | Caergeiliog
Development of six semi-detached low energy dwellings utilising homegrown Welsh timber MMC.
Realised as part of the Welsh Innovative Housing Programme, Tre Ifan is the first multi-unit social housing scheme to be built in Wales using Welsh timber-based, volumetric construction.
Located in the Northwest of Anglesey, Tre Ifan sits within the small village of Caergeiliog, which lies under the RAF Valley flight path, between the astonishing backdrop of Eryri National Park and the beautiful, exposed and harsh coast of the Irish Sea. Although an Area of Outstanding Natural Beauty, the built environment of Anglesey itself, particularly in the immediate context, is simple and unremarkable: pebble dashed modest mid-century housing focused specifically on responding to the harsh environment with robustness. Tre Ifan forms an infill site within an existing estate of council owned homes.
The scheme forms 3 pairs of 2 bed, 4-person, semi-detached, affordable homes, designed to meet the Welsh Design Quality Requirements and attain exceptional fabric performance whilst also employing low carbon materials. Each property comprises 5 offsite fabricated modules, incorporating bathrooms, kitchens and primary living and sleeping spaces.
Originating as an R&D project led by the Welsh School of Architecture and woodland management charity Coed Cymru, the roots of Tre Ifan set a compelling aspiration to make better use of homegrown timber resources and the Welsh timber supply chain to create high quality, high value products capable of supporting and enabling a robust and sustainable natural woodland resource.
Despite the challenges of Covid, the project set out and delivered extremely high aspirations. In design we set out to advance our understanding of designing for volumetric – both in space planning within the tight constraints of the Welsh Design Quality Requirements, and resolving technical challenges. These included complex issues around foundations and ground junctions, airtightness and the integration of mechanical and electrical systems, particularly whole house MVHR – always a challenge even in ideal circumstances.
On the manufacturing side, the transition from a 2D component facility to a full volumetric housing factory was a major achievement. This involved extending the existing factory, developing new lifting strategies for both in-house operations and onsite installation, and assembling a multidisciplinary team capable of working within a factory environment to deliver exceptional levels of detail and quality. At every stage, the project prioritised sourcing local, low carbon materials and developing sustainable supply chains.
Manufactured entirely in a factory setting, the volumetric solution delivers significant reductions in both upfront embodied carbon and construction waste, compared to traditional masonry builds and 2D pre-manufactured components (Category 2 MMC). Each pair of homes was installed onsite in a single day as a weathertight structure, with factory based quality control ensuring extremely low levels of construction related defects – demonstrating the clear success of the approach.
The project combines homegrown timber with recycled newspaper insulation; triple glazed windows and doors; and locally sourced homegrown timber and natural slate finishes to the exterior and interior. The fabric was designed to minimise acoustic disturbance from the RAF flight path and delivered impressive high efficiency and performance levels as listed below:
Construction type
Off-site volumetric timber
Airtightness
<0.6m3/hr/m2
U-Value
0.12 – 0.15W/m2K
Energy Management
MVHR, space heating and Photovoltaics
EPC
93A