James Jones Group's showcase sawmill is hosted at their Lockerbie site. Their new visitor building at the site boasts a huge amount of their timber products, but keeps functionality, flexibility and accessibility in mind.
The idea for the visitor building recognised the need to provide increased office accommodation, better visitor facilities, and the opportunity to host on-site training courses and industry meetings, which previously had to be conducted offsite.
The brief for the building was part functional and part aspirational. At a functional level, there was a requirement to provide office accommodation for up to 10 staff, a meeting room capable of holding up to 30 people theatre style, with the flexibility to hold classroom sessions and industry meetings and, in addition, a smaller meeting room, kitchen facilities and a reception area for visitors.
James Jones & Sons held a design competition between two architectural firms and the winning team was Konishi Gaffney from Edinburgh, led by Kieran Gaffney.
Being based at a sawmill, the building has a high timber content, using as many of James Jones’ product as possible, complete with a view across the Lockerbie site allowing visitors the opportunity to see the sawmill in operation.
The completed building’s structure acts as a demonstration project, almost entirely erected from James Jones & Sons own products with an approach to minimising the use of steel and maximising timber. Loadbearing glulam beams were used throughout the building, while an unprocessed tree trunk provides loadbearing support to the backbone of the building; a nod to the timber processing cycle.
The building takes the form of two offset pitched volumes: a single storey office wing to the north and a two-storey volume to the south which houses the reception, meeting rooms and the conference space above. A simple, unheated, glass link building connects the new building to the old office. The 1st floor is raised to give panoramic views across the timber yard and over the constant stream of unprocessed logs to the mill, which is directly below this space.
The walls are formed with an innovative double-leafed, offset structure, using James Jones & Sons proprietary timber JJI joists, to minimise cold bridges. These extra thick walls, at 430mm deep, allowed sufficient depth to use environmentally friendly insulation, with excellent thermal performance. It also facilitated a deeper articulation of window reveals in an area of Scotland known for its high rainfall. The remainder of the structural timber is James Jones’s C16 graded spruce to demonstrate the usability of British grown C16 timber in the majority of construction projects.
Internally the material palette is restrained; white plaster, black framed Crittall-style doors and whitewashed oak flooring (the only hardwood in an otherwise softwood building). Douglas Fir has been extensively used in the interior for its stability and characteristic pink hue. The pitched roofs feature closely centred and very narrow Douglas Fir rafters, 160mm deep by 25mm wide that bring rhythm and warmth to the spaces. This pattern is echoed in the overclad reception wall and the balustrade to the staircase, top-lit by the full-length roof light above.
Externally Scottish larch was specified with black stained, narrow, vertical cladding on the lower storey of the building. Above this, the horizontal larch cladding is finished with a water-based silicate treatment that preserves the timber while accelerating and evening out the weathering.
Taking all the timber elements into account, the building fabric has almost 40 CO2TE within it. The building’s environmental agenda goes beyond the extensive use of timber: an air source heat pump provides a renewable source of heating and summer cooling to the building. The various vents and ducts for this system, the bathrooms and kitchen are carefully expressed in the timber cladding on the South Elevation. Electric car charging further demonstrates the company’s commitment to its inherently green credentials.
First published on James Jones Group's website