/ 9 September 2011

Innovative design and construction methods show the way forward

To mark the hosting of the 12th International Housing and Home Warranty Conference in South Africa, the department of human settlements and the National Home Builders’ Registration Council launched the Legacy Project on July 18.

The project is a model of high-density housing using eco-friendly and alternative building technologies.

“There is a dual purpose to the Legacy Project,” says Jeffrey Mahachi, acting chief executive of the council. “The intention is to showcase South Africa’s potential regarding sustainable human settlements and to provide a model for housing development that offers alternate solutions to assist with the housing backlog.”

In South Africa there are 2.4- million people who need homes. Mahachi says the department wants to eradicate the backlog by fast-tracking developments. If existing building methods are used, this will take 30 years. “It’s about considering alternative building materials and building processes,” says Mahachi.

Lerato Khumalo, a structural engineer at the council and the project manager of the Legacy Project, agrees: “In trying to meet the housing backlog, there are issues in terms of managing quality, cost and production. While the emphasis is on fast-tracking the process, there needs to be a balance between job creation, the cost of producing and what the product should be, among other variables. A house is more than a box with windows.”

Towards sustainable housing
The factors to be considered go beyond that of simply the structure and include the infrastructure and services (such as water, sanitation, energy and access) that supply the dwelling. The neighbourhood is also significant, particularly the availability and access to facilities such as educational institutions, hospitals and police stations.

The connection between housing and income generation is also important — housing needs to be close to work opportunities, with a convenient, safe and affordable means to travel to work. In the case of subsidy housing, erecting houses that don’t take economic activity into consideration has resulted in the sale or rental of these houses and the owners returning to informal settlements closer to economic activities.

Urbanisation is increasing and, Mahachi says, researchers predict that 70% to 80% of the world’s population will live in cities within the next 50 years. Rapid urbanisation impacts on land availability, creates pressure on urban services and infrastructure, increases congestion and results in environmental deterioration.

According to Mahachi, cities produce 80% of CO2 emissions, with buildings being a major contributor. The Constitution says that all citizens have the right to “adequate housing” and South Africa is committed to the Habitat II Agenda, which acknowledges the international right to adequate housing.

The emphasis is on sustainable human settlements rather than the mere provision of housing. “It’s about the triple bottom line of sustainability — socio-economic, technological and environmental,” says Khumalo.

An interim solution
The Legacy Project consists of eight units in four blocks, each comprising two semi-detached double-storey units of 60 square metres, with a footprint of 30m2 for each storey. The development is being built in Conifers Blue Down in Cape Town on four sub-divided erven and each semi-detached house costs R250?000. Construction began on July 18.

The Legacy Project does not attempt to be the blueprint solution to all of South Africa’s housing problems but it does, instead start a process towards improvement. This project is one of the building blocks in finding sustainable solutions. Government partners. The Legacy Project was initiated by the council but falls under the housing department.

Mahachi says the project is an example of a public-private partnership, a model that is being prioritised by the department. The Western Cape department of human settlements has made land and funding available and is providing consumer home ownership education to the beneficiaries.

The City of Cape Town, another partner, is fast-tracking the development processes. Electrical wiring services are being provided by the department of energy and Eskom. The department of agriculture is greening the Legacy Project.

The council, which plays a consumer protection role in South Africa and regulates the home-building industry, is managing the development and ensuring that the systems and technologies meet the required technical standards.

A sustainable development
Conifers Blue Downs is in a developed neighbourhood that is close to amenities. “Conifers is a lower-middle income area. The Legacy Project needed to fit into that context with a demonstration of sustainable design within the social housing category,” says Khumalo. “This category describes people who earn too much for government-subsidised housing but too little to obtain a substantial mortgage. It’s a fairly large market that usually rents.”

It was emphasised by the Western Cape department of human settlements that land for development in Cape Town is becoming scarce and finding solutions of maximising the use of the site was essential. It was decided that the four erven provided would be sub-divided into eight full-title stands to enable building eight semi-detached 60 square metre houses instead of four. Also, by reducing the footprint of the houses to 30 square metres building double-storey instead of single storey would provide north-facing units on east/west oriented sites and leave external living space for functions such as gardening.

“While there is a shortage of housing, the major problem is lack of employment. The vegetable gardens can provide a certain amount of sustenance and vegetables can potentially be sold or used to barter with neighbours,” says Khumalo. She emphasises that the Legacy Project is only a transitional solution to a larger problem. Even the paint colours were considered, with vibrant earth colours used to represent the African heritage. One wall surrounds all the units. Even though there are picket fences between the units, the intention is not to isolate neighbours.

Innovative technologies
The aim of the Legacy Project is to build houses that are energy-efficient, structurally sound and durable. “We looked at alternate building materials, as well as manufacturing processes that could provide benefits such as quality, economy, safety and durability. And also contribute to fast turnaround times,” says Mahachi. “One should be able to erect a structure within seven days, using sustainable building materials and with an environmentally friendly design.”

Lepa, a sponsor, provided sandwich panels that uselightweight concrete with expanded polystyrene beads. Although lighter thanbricks and mortar, it has better insulation and fire resistance and is quicker to build because of an interlocking tongue-and-groove method. Kusasa provided the light steel frames, with cladding from Knauf. Again, these are quicker to erect than traditional building methods.

Rehau South Africa is supplying the energy-efficient uPVC windows. The Concrete Manu facturers’ Asso ciation (CMA) is using modified traditional methods with two types of interlocking concrete blocks, one of these manufactured from recycled material. It is also making use of a high-strength, thin-bed mortar.

Khumalo says that the association’s solutions help eliminate some of the traditional problems such as incorrect mortar mixes and water penetration. The stacking of the blocks also prevents incorrect wall alignment and speeds up construction.

Geoplast South Africa is using modular plastic blocks, along with concrete and steel, to create a monolithic ventilated foundation that requires less concrete than traditional methods. Other sponsored materials and services include: solar water heating by the CEF Group and Tasol Solar; concrete roof tiles by CMA pavers; environmentally friendly paint from Midas Earthcote Paint; slimline water tanks from Jojo Tanks; and Group Five/Motlakar Cape is assisting with site management.

A large percentage of the funding is being provided by product and service sponsors, as well as British American Tobacco and the Canadian Home Warranty Council.

This article originally appeared in the Mail & Guardian newspaper as a sponsored feature