Foundation (engineering)
Foundations are designed to have an adequate load capacity depending on the type of subsoil/rock supporting the foundation by a geotechnical engineer, and the footing itself may be designed structurally by a structural engineer. The primary design concerns are settlement and bearing capacity. When considering settlement, total settlement and differential settlement is normally considered. Differential settlement is when one part of a foundation settles more than another part. This can cause problems to the structure which the foundation is supporting. Expansive clay soils can also cause problems.
Bodrifty
In 1999 Fred Mustill, a local smallholder, built a reconstruction of a roundhouse at Bodrifty Farm after receiving a small grant. The task of building the replica required the shifting of granite rocks weighing several tons, felling, shaping and lashing hundreds of feet of timber, and hundreds of hours' work cutting reeds for the roof. Mustill had previously researched typical roundhouse architectural structure and surveyed other reconstructions in Cornwall. Traditional rab (granite sub soil) was used for the mortar and woods such as oak, ash, holly and hazel for the roof. Mustill was keen for the house to be showcased as an educational aid for local children and others interested in history and archaeology, and hoped it would become a registered charity, though as of August 2011 it was being used for "luxury camping".