Grand Designs ‘Cob Castle’ Features Polypipe Heat Recovery System

Kevin McCabe is the leading living exponent of the ancient art of cob building – building houses out of clay, sand, straw and water.

Kevin built his first cob house in 2002, but his dream was to build the world’s largest cob house – at 10,000 square feet, more castle in size! – to the highest environmental performance targets ever set.  The aim is to meet Code 6 of the Code for Sustainable Homes and use less than 5kw to heat the entire building.

Based in East Devon, Kevin started his dream project in 2012 and by the end of 2013 has created a truly unique property formed of two vast curved cob roundhouses, the largest of which is inspired by the natural geometry of a snail shell.

The houses are connected by glazing and topped with undulating wild-flower meadow roofs to mirror the surrounding countryside.

The property is constructed from concrete foundations with blockwork on top, then a mind boggling 2000 tonnes of cob clad with polystyrene and lime rendered for insulation.

The property is extremely air tight and super insulated, so therefore requires adequate levels of ventilation.  Kevin opted for Polypipe Ventilation’s Mechanical Ventilation with Heat Recovery and Radial Ducting Systems throughout the property. 

As Grand Design’s presenter Kevin McCloud explains “for the system to work a blue spaghetti of ducting needs to be threaded through the entire building.... each tube will lead to a heat recovery unit in the plant room.

Stale air from the bathrooms and kitchen will be extracted through the appliance and then get blown outside the building, whilst incoming cool fresh air is pulled in.  The key is the separation of the air layers creating lots of surface area, whilst it transfers the vast majority of heat from one air flow to the other”.

The cob house is an ongoing project for Kevin McCabe, who is currently waiting for a buyer for his existing house in order to get the funds to complete this dream project.

For further information, please contact Polypipe Ventilation on 03443 715523