Case Study 5 – Creagan Gorm


Alexanders Timber Design
Inside Housing Sustainable Housing Awards 2009, Sustainable Smaller Social Housing Project of the Year
Roses Design Awards 2009, Bronze Award for Sustainable Design
Timber technologies
The cottages were constructed using SC16 grade locally sourced Scottish Spruce. Externally the houses are clad in semi-durable and untreated Larch (heartwood of European Larch). It is well protected from the weather by overhanging eaves, and care has been taken to ensure the cladding is well ventilated.
The heartwood of European Larch is a class 3 durability timber. It cannot be affected by decay unless it is constantly in a moisture condition of above 23% moisture content. Provided the façade is ventilated and detailed correctly this cannot occur, even in Fort William! The large overhanging eaves offer further protection to prevent excessive moisture contact with the boards.
In exposed conditions the cladding boards can lose approximately 1mm every 15 years. Once 4mm has been lost fixings could become loose and boards may be affected by board length splits. They can then be recycled by chipping for bio fuel, or reused in other less demanding uses.
Special timber-related features
Over time the Larch cladding will turn silver grey in colour. It will last at least 20 years before more exposed boards need to be replaced.
The lifespan of the timber structure is at least 60 years, however, if it is maintained properly it should last far beyond that.
Background to building
Creagan Gorm Cottages provide functional, robust and affordable social housing for key workers in the heart of the Cairngorms National Park.
This project was a pilot scheme, designed to examine how to maximise the use of Scottish timber and minimise energy use throughout the construction and occupation of the homes.