Cornish Sea Salt

This scheme was designed in two phases for a new company producing culinary sea salt using an innovative process. The completed first phase houses the production plant, and the second phase will provide offices.

After a long search, the disused quarry at Porthkerris was identified as the ideal site, even though a number of difficult planning issues had to be resolved. These included local and national planning policies regarding development in rural areas, use of brownfield land, visual impact and the provision of local employment.

Transportation issues included difficult site access through narrow country lanes. There were also significant environmental issues to resolve as the site is adjacent to the Fal and Helford Estuaries SAC, and is within a SSSI with national geological importance. An Environmental Impact Assessment was produced by Spalding Associates and this informed the design work, resulting in support from the Local Planning Authority and all consultees. The special qualities of the site and the unique production process required a design solution incorporating significant sustainability concepts to minimise the impact of the building and processes on the landscape.

The building is highly insulated with cellulose, and the office areas will be heated with waste heat from the production process. Rainwater is harvested for re-use, there is no mains water supply, and foul drainage is treated by a packaged treatment plant.

The form of the building is shaped by consideration of the process plant, sunlight, shading, rainwater collection and rockfalls. The process plant itself is highly efficient. Materials are locally sourced, renewable and eco friendly, mostly self finished with low embodied energy. Aggregate was sourced from the site and the timber cladding is recycled.

The design of the building aims to minimise its visual impact on the site, using dark cladding on a laminated timber frame to blend with the cliff face behind, and placing the building so that it screens the service yard from view from the sea. Castria managed the entire design and procurement process and completed the building on time and to budget using a two stage tender and a JCT Private with Quantities building contract, 1998 edition.