For hundreds of years there has been little revolution in the construction industry in terms of design and materials. As Professor Mitch Gohnert of the University of Witwatersrand (WITS) states, “to change the way we build we need to consider both the design and materials”. WITS masters student Vanja Bulovic took these words to heart and decided to do her thesis on sustainable low-cost housing with different materials and not necessarily using conventional designs.
Since some 30% of the building cost in standard houses is spent on the roofing structure, which does not add to living space, Bulovic theorised that it would be possible to reduce the cost by also using roofing space for living space. This led her to designs featuring an inverted catenary curve to produce a curved roof that holds its own weight under perfect compression.
In practice she was able to produce the design by using Hydraform interlocking blocks. This resulted in still more cost savings through the shorter construction time and only needing mortar in 30% of the structure. The Hydraform splitter brick was then used to build the curved roof structure.
The house Bulovic constructed at WITS has an area of around 75m2 – almost double that offered by current lowcost housing. As it stands, and without factoring in labour and finishings, the dwelling cost just under US $10 000 to construct. The dwelling is being tested for thermal efficiency and is expected to perform significantly better than conventional brick-and-mortar structures.
Hydraform’s hope is that, once fully tested, the WITS Hydraform house can be replicated in any developing country. Further cost advantages could be gained by involving communities in the production of blocks and construction, thereby also creating jobs.
We’ve all been faced with this situation before. You need equipment or a spares part, you’re a bit low on cash…and it becomes very tempting to take the easier, ‘cheaper’ route and get non-original parts. You save time, and money… right? Wrong!