The CMA House
Blueprints for sustainable housing
The Concrete Manufacturers Association (CMA) is offering architect-designed plans for a 40m² subsidy house at no charge to anyone wishing to use them. Dubbed the CMA House, it is an initiative which if adopted by the construction industry will improve the quality and building productivity of subsidised housing dramatically. The project was officially launched in September 2012. Modular masonry using concrete blocks forms the backbone of The CMA House.
The major difference between modular and non-modular masonry lies in the detail, especially in the plans and schedules. Besides the walls, doors and other dimensions, the plans detail each and every block used. This reduces the need for odd-sized units and the associated wastage of time and materials so prevalent in non-modular masonry. The CMA House or, more accurately, two houses, were designed by an architect using two different masonry units, one used largely inland and the other in coastal regions. The inland set is based on the 290 x 140 x 90mm solid block. The coastal set is based on the 390 x 140 x 190mm hollow block. The 140mm width of both units provides enough structural integrity based on the SANS 10400-K standard and is more economical than the 230mm width of a standard wall.
Each CMA-house plan includes: a full set of drawings; a normal raft foundation or an alternative Agrément-approved precast concrete hollow-core option; modular masonry; and concrete roof-tiles. The plans also include: schedules for block-cutting and for matching door and window frames to masonry units; recommendations on waterproofing external wall surfaces; and some energy-efficiency options.