The Concrete Manufacturers Association (CMA) is offering architect-designed plans for a 40m² subsidy house, at no charge, to anyone wishing to use them. This initiative is seen by the CMA as one which, if adopted by the construction industry, will improve the quality and building productivity of subsidised housing significantly. Dubbed ‘The CMA House’, the project was officially launched by CMA director, Hamish Laing, at the South African Housing Foundation Conference in September last year.
Laing says the use of modular concrete masonry 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 to be used. This reduces the need for odd-sized units and the associated wastage of time and materials so prevalent with non-modular masonry.”
The CMA House or, more accurately, two houses, were designed by an architect using two different masonry units, one that is used largely inland and the other in coastal regions. The set of drawings for the inland house 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 that provides for a normal raft foundation or an alternative Agrément-approved precast concrete hollow-core option, the use of 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.
Laing says a double-storey version of the CMA house is also on the cards and two experimental houses based on this model have already been built: they formed part of the Housing and Home Warranty Conference (IHHWC) Legacy Project constructed in Cape Town last year.
Both sets of drawings for The CMA House are available on the CMA website.