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Architects: Feilden Fowles
- Year: 2009
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Photographs:David Grandorge, Fergus Feilden, Edmund Fowles
Introduction
Situated in the midst of the Brecon Beacons, this linear Greenfield site in the village of Trallong has a southerly aspect and fine views towards Pen Y Fan. The rich local vernacular inspired the concept of a modern 'long house', following the contours of the land, embedding itself in the slope of the hill and responding to the prevailing conditions. We spent two years researching and developing this design through site visits, models and prototypes. The design evolved into a crisp extrusion using skilled craftsmen to deliver a high-tech building. This period was used to procure local materials, research and to develop our Welsh vernacular adaptation. The typology of the long house leant itself to a passive solar plan, enhanced by the topography and aspect of the site. Contemporary construction techniques have delivered a thoroughly modern and high performance building, which responds to the landscape. The design was environmentally driven throughout. The passive solar design strategy uses every natural energy source available, and is supplemented with active features such as the log boiler.
Project History/ Background
Ty Pren was first conceived in 2005 by our clients, Gavin and Vina Hogg, committed environmentalists responsible for managing the Penpont Estate (recently awarded the Forestry Commission’s ‘Wales Business and Sustainability’ award), with the desire to create a uniquely environmental building drawing strongly from the Welsh vernacular. They placed their faith in Feilden Fowles, a young design team straight out of Part 1 and embarking on our first major project. This precedent of mutual trust and good will, underpinned by a shared commitment to sustainability and green design, was shown by the entire design and construction team. This enabled the delivery of an exceptional building, small in scale but with huge ambitions. The client, acting as a construction manager, had a holistic environmental approach that facilitated the efficient delivery of a sustainable building within a tight budget, and ensured both the design and its delivery remained under continued scrutiny. The embodied energy of materials remained under constant review and often took precedent over cost.
Design Approach
Due to the particularly sensitive location, situated on the edge of the Brecon Beacons national park, discussions on the vernacular were numerous throughout the early stages of design. Phrases like ‘sense of space’ and ‘local identity’ are abundant in the current debate regarding Welsh Architecture. Mathew Griffith’s suggested in ‘About Wales’ that ‘...the concept of ‘place’ is located at the heart of a fresh way of doing things. We need to be more effective in defining both the character of places and the value and significance that people attach to them...’ The real strength and identity of the Welsh culture is found in their simple plain chapels and vernacular buildings embedded in the countryside, gradually added to and elaborated. We were keen to take reference from these while avoiding simply reproducing an explicit version of the historic vernacular, an approach that would devalue the original. Instead we hoped to reinterpret, not necessarily by imitating historic details or using authentic materials, but through a subtle reinterpretation of familiar forms and ideas coupled with an holistic approach to environmental sustainability.
Materials
Ty Pren translates literally as 'House of Wood', as timber drove the design strategy throughout. The building was clad in larch, sourced and felled from the client’s estate two miles away, and subsequently milled on site. The untreated cladding has a predicted life of 25 years; eight larch trees have been planted on the client’s estate to replace this when necessary. The removed cladding will be burnt to heat the house. Recycled welsh slates from derelict buildings on the estate wrap over the roof and down the exposed north wall. The east, south and west ‘Solar Elevations’ incorporate a more filigree larch skin. The use of Structural Insulated Panels (SIPs) coupled with the high performing windows has resulted in a super airtight building. Secondary insulation (Thermafleece) made from a sheep’s wool blend was used to reach a U-Value of 0.15W/m2K in the walls. Internally locally sourced oak was used on the fit-out, and the entire north wall constructed from sustainably sourced birch-faced plywood. Lime based plasters and paints from Ty Mawr lime were used throughout. These natural materials are non-toxic and have a low embodied energy.
Exterior
The low embodied energy, flexibility and character of larch lent itself perfectly to this environmental house; particularly given that the client, an arboriculturalist, was able to source much of the timber from within his woodlands. The larch was felled just two miles away and sawn on site with a mobile sawmill. It was fitted green in order to naturally weather to a silver-grey, complementing the moorland backdrop. New trees were planted within the client’s woodland when the original cladding was felled, starting a rolling 25-year timber life cycle. The discarded cladding will then be burnt to heat the house, harnessing the last of its energy.
The solar facades include deep-set window reveals that prevent excessive solar gain, while sliding shutters avoid overheating to the first floor spaces. The larch was sawn into chamfered battens, mounted 10mm apart and set out on 100mm vertical studs. This improves ventilation, produces a filigree appearance to the rain screen cladding and incorporates flush eaves details that emphasise the crisp 'long house' typology. Larch boards are inserted into the window reveals, covering the window frames and highlighting the punched openings.
Interior
The plan is modernist in its simplicity, set out on a 1.2m grid, driven by the standard SIP panel and sheet material size. The continuous birch-faced ply north wall incorporates all the services and utilities, including bathrooms, stairs, pantry, storage and solar thermal store. This wall is articulated by home-grown oak studs with shadow gaps running along the datum lines of the house. The pop fit doors deliver a seamless and subtle wall, structuring the space. The stair is recessed into the depth of the back wall, emerging on the viewing gallery with direct views north, west, east and framing Pen Y Fan to the south. Welsh oak floorboards run the length of the upper gallery and throughout the lower ground floor expressing the linear design.
