Last year Patrick reported on the progress of 10x10, the social housing project launched by Cape Town's Design Indaba with the aim of approaching ten of the world's best architects to help build 100 new homes in the Freedom Park district of Mitchell's Plain, one of the many townships that make up the vast area known as Cape Flats. On Saturday, Luyanda Mpahlwa, the architect behind the first series of houses to be built for the project showed the 2009 Indaba guests some finished examples: one of which, shown above, is now a new home to Mrs Jonkers and her family; the first inhabitants of Mitchell's Plain to see the benefits – and illustrate the potential – of the 10x10 project...

Luyanda Mpahlwa addresses the 2009 Indaba guests

As the 10x10 initiative rolled out, architects such as David Adjaye, Thomas Heatherwick, Tom Dixon and Shigeru Ban submitted designs developed in conjunction with South African-based firms for the project.

But it's MMA, Mpahlwa's Cape Town-based architects firm, who are the first to see their designs through from planning stage to building site. Their aim, as Mpahlwa put it during the talk he gave at the Indaba conference, is "to create dignified social spaces" that will end up "empowering future generations".

Some of the essential materials in building Mpahlwa's houses include timber frames, right, that will support walls of sandbags. This forms part of a locally-produced system known as Ecobeams

Two of the completed houses (the orange one is Mrs Jonkers')

To construct the walls for the houses, sandbags are assembled inside timber frames and then plastered over, with strong wire attached to the corner sections. The interior 'ring beam' carries the weight of the upper floor and is, Mpahlwa explained, their only concession to concrete in the build.

The houses are modest in size, at 15m long by 7m wide, but in order to help redistribute the knowledge involved in their contruction, the designs for each are available as open source materials for other architects to use.

Sandbags are harnessed together in a timber frame to create the walls. This is then plastered over and painted

The essence of the 10x10 project, Mpahlwa explained, was about "changing the mindset in South Africa – to see if we can find ways to use different materials. Sand, for example, has a very good thermal quality and doesn't let moisture through."

The speed at which the project has moved has increased over the last few months as the builders and engineers become more familiar with the materials. "The last eight houses were put up in twelve weeks," Mpahlwa added. "Once you know the craft, it gets easier."

Inside, the thick sandbag walls mean that the temperature remains cool

Another shot of the ground floor. Upstairs has another two rooms

After his ten houses, Mpahlwa's next development is set to be a high school. Yet his main concern is that the lessons being learned through 10x10 may be being ignored by the very people who need to listen. "The South African building industry does not support alternative methods," he said. "Ours is just an office of 20 people and we had an opportunity here – but it requires a broader involvement." The current budget for each house stands at ZAR 74,000, or around £5,000.

But what of the materials to hand – while sand is in plentiful supply and the locally-made Ecobeam framing method works perfectly for houses of this size, are these exposed buildings able to perform against the harshest of Cape Town weather systems?

"Water is an issue," Mpahlwa considers. "But sandbags have been used during floodings and they are a solution that works. During the storms last August, while Mr Jonkers' house was completed, this green one was half-finished. After the storms I phoned our builder, I was in such a state, to find out if it was still standing. It was."

Consideration has even been made for a terrace to be erected on the beams over the entrance at a later date