What are the thermal/insulation properties of cob?
A. Cob is well know for being a very comfortable material in which to live; in part this is due to its excellent thermal properties, being a combination of high Thermal Resistance and Thermal Storage and good humidity regulation. However, from a building regulation point of view (in the UK) only Thermal Resistance is taken into account. An 860mm thick cob wall, lime plastered and rendered, bringing the total thickness to 900mm, [which is much thicker than a traditional cob wall] will give a thermal resistance of 0.45w/m/k. In practice in a new build situation it is usually necessary to put extra insulation in the plinth to compensate for this perceived inadequate value.
