Green building interventions for low cost housing demonstrated by Cato Manor Green Street Project

Submitted by: Amanda Botes, Tuesday, November 6, 2012

<p>This street in Cato Manor was retrofitted with green building interventions prior to COP17. Residents have named their street ‘Isimosezulu (which means ‘climate’) COP17 Place’ (Image courtesy of  Willem De Lange GBCSA).</p>

This street in Cato Manor was retrofitted with green building interventions prior to COP17. Residents have named their street ‘Isimosezulu (which means ‘climate’) COP17 Place’ (Image courtesy of Willem De Lange GBCSA).

Substantial savings in water and electricity savings could be made and the quality of life for low-income residents improved, if the RDP houses built since 1994 were retrofitted with green building interventions like those implemented for the Cato Manor Green Street Retrofit Project, says Nick Alcock, of Khanyisa Projects.

The Cato Manor Green Street Retrofit Project is an initiative of the Green Building Council of South Africa (GBCSA) to green 30 low cost houses in one street in the suburb of Cato Manor in Durban. The project involved retrofitting existing houses with a number of different green building interventions for low cost housing to help reduce resource use by the households and enhance their quality of life.  

Alcock from Khanyisa Projects, the organisation that managed the implementation, says “the project was about changing people’s lives as well as doing research in terms of how well these different technologies worked in terms of reducing energy consumption and water consumption… they [the GBCSA] wanted to create a legacy, a place where learning could happen to … possibly influence policy for RDP housing going forward.”

Approximately three million low cost houses have been built by the South African government since 1994 but no attention has been given to energy efficient design of these houses, says Alcock. The Cato Manor Green Street Retrofit is an attempt by the GBCSA to demonstrate the social, economic, health and environmental benefits that can result from sustainable design and resource efficiency interventions in low cost houses.   

Green building interventions for low cost housing

The project involved the implementation of the following green building interventions in 30 low cost houses (30 square metres in size) in a single street in Cato Manor:

  • Solar water heaters and pipe reticulation systems were installed to supply hot water directly to residents.
  • Insulated ceilings with a thermal resistance value of one were installed to assist with the warming and cooling of the houses.
  • Dangerous electrical wiring was replaced and new reticulation to plug and light points was provided.
  • An average of four compact fluorescent bulbs was installed in the houses and an extra light installed above the entrance for safety.
  • A locally produced heat insulated cooker (Wonderbag) was supplied to each of the households which helps to reduce time spent cooking meals on a heat source. This saves on energy, improves the indoor air quality and reduces the possibility for fires and accidents.
  • Twenty seven of the houses received rain tanks which help to provide emergency water supplies in times of scarcity and can also be used to irrigate gardens or for laundry.
  • Food gardens were established for those that were interested and training provided.

Energy savings

Overall there was a slight increase in electricity demand after the intervention which could be due to the short measurement period of time and complexities related to the context of the area. Alcock elaborates on one possibility for the increase in electricity use “Cato Manor is a particularly strong example where there are at least 20-30% of people selling electricity to informal houses near them or they have built extensions which they rent out and they either include electricity in the cost or charge them separately, so it becomes complex to monitor electricity consumption…it cannot be assumed that residents are the only users of a meter in low cost areas.”

Overall the most popular intervention rated by the residents was the solar water heater which allowed residents to have access to hot water on tap.

Comfort levels

Installed ceilings have helped to increase comfort levels inside the houses(Image courtesy of  Willem De Lange GBCSA). The addition of ceilings helped to increase comfort levels inside the houses with a reduced temperature of between four and six degrees Celsius during the hottest time of the day. On two of the houses insulation roof paint was painted on the roof which assisted in decreasing the temperature by a further two degrees in summer. During the evenings, however, an increase in temperatures was experienced due to poor ventilation of the houses as residents closed their windows for security reasons. Ventilation will be researched in the second phase of the project says Alcock.

Improved health and safety

Because of the energy saving interventions there has been a reduced need for fuel such as wood, paraffin and coal. This has resulted in improved indoor air quality and reduced risk of fires and accidents.  Safe wiring has also prevented risk of electrical fires and shocks. Security has also improved because of the improved lighting at the entrance of the houses.


A number of residents were employed, and trained, to work on various aspects of the project including:

  • Installing rainwater harvesting systems
  • Planting trees and creating food gardens
  • Installing solar water heaters and plumbing
  • Installing ceilings
  • Electrical work
  • Clean up campaigns
  • Assisting with stakeholder engagement

Water use

Water usage was expected to increase with the installation of solar water heaters but a slight decrease was experienced which could be due to increased use of water from the rainwater tanks or because of training on how to use water more efficiently said Alcock.  

Food gardens

Food gardens and fruit trees were planted as part of the greening interventions (Image courtesy of  Willem De Lange GBCSA). A post survey revealed that most residents saw the value of having a food garden but many of the gardens were not well maintained. On the sustainability of the gardens Alcock says “We generally found that those that had gardens before the intervention maintained them, but those who had not left theirs to rack and ruin.”

Sustainable building regulations

Alcock was positive about the new sustainable building regulations that have been released by the South African government but was unsure if these regulations would be enforced in the low cost sector. “Government has recognised the need for more sustainable housing programmes in the new regulations that have come out … but it remains to be seen if the regulations will be enforced in the low cost sector” said Alcock.

The Cato Manor Green Street Retrofit Project was led by the GBCSA in association with the World Green Building Council. Khanyisa Projects were the project managers and received support from various departments within the eThekwini Municipality and the local councillor. The first phase was primarily funded by the British High Commission and the second phase will be funded by the Australian Government.

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Amanda Botes