Architecture and Design Scotland is a key partner in Retrofit Scotland, a collaboration of organisations established to disseminate best practice in refurbishment within Scotland.
We have been involved in the refurbishment of Cultybraggan Hut One, a Nissen hut originally built for a Prisoner of War Camp in Perthshire. Through our Library of Sustainable Materials at the Lighthouse we were able to offer the project Architects assistance in securing a variety of innovative materials to showcase in the project. While the materials have been sourced from throughout Europe one of the project aims was to pose the question of which materials could potentially be manufactured in Scotland? Some of the materials explored in the project included wood-fibre insulation, hemp batts and clay plaster.
While innovative materials can offer a lot of potential, in some Retrofit Scotland case studies both cost and resource efficiency have been key factors, and re-using existing elements have both served to save money and reflect the building’s history. At Norton Park, in Edinburgh, a school building refurbished as workspaces, care was taken to salvage and re-use as many materials as possible, including wall tiles, radiators, doors and floorboards. Materials that were specified from outwith the building were from local, natural and sustainable sources, and re-claimed if possible.
While reusing materials at Norton Park was a purely functional endeavor, at the Glad Café in Glasgow it has been the playful re-use of materials that set the design apart, these innovations range from wooden floors which reveal the court markings from their former use in a sports hall, to off-cuts from a local sign writers which have become a prominent handrail.
The refurbishment of historic A-listed Acheson House, on the Royal Mile in Edinburgh, while a traditional refurbishment, also poses a question about which materials we should be focusing on in Scotland. A rare example of a stone tiled roof, it had become dilapidated to the state that only one third of the stone tiles could be re-used on the refurbished roof. The recently re-opened Denfind quarry provided a historically accurate and appropriate roofing material for this conservation project. The benefit of finding a source of an appropriate material in Scotland is twofold: it could open up opportunities as a future source for roofing stone, linked to local employment and development of new (old) skills, which are essential in the conservation of historic buildings, but which could also be adapted for use in new buildings.
Key to the Retrofit agenda is finding the best interventions for Scotland’s most predominant forms of housing stock. Through the upgrade in Sword Street, a tenement of 6 flats in Glasgow, Historic Scotland were given the rare opportunity to test a variety of insulation materials and thicknesses. The uniform façade was upgraded using a different vapour-permeable insulation material in each flat including: hemp-board; wood fibre-board; blown cellulose; bonded polystyrene bead and two different thicknesses of aerogel board. Following refurbishment the improvement in the U-Value of the wall was measured in each flat. The material in the study to make the best improvement was 80mm of wood fibre-board, a fact which may help answer the original question posed by the refurbishment of Hut One.