Researchers at Stellenbosch University (SU) have found that South Africa has sufficient log resource options for a sustainable wood residential market.

SU Department of Forest and Wood Science's Dr Philip Crafford says the research study showed that, with the use of wood resources currently exported as chips, as well as planting trees in areas that have been earmarked for afforestation, “it will be possible, in the long term, to sustain a future residential building market where all houses are built with wood”.

Crafford and his colleague, Dr Brand Wessels, investigated the country’s log resources and the potential global warming impact of an increasing wood-based residential building market.

The researchers wanted to determine whether local forest resources would be able to supply the required wood for substantial growth in wood-based residential development in South Africa, and in order to do this, they analysed the residential housing footprint in the country; available log resources for wood-based buildings; and the likely environmental impacts of such a building system.

“[Owing] to the limited forest cover in South Africa, the perception is often that significant increases in the market share of wood-based buildings are not possible, at least from local wood resources. Our study showed that this perception is not correct,” Crafford says.

He adds that, when considering only the current available wood chips as a resource, 39 646 wood-based homes (30 523 houses and 9 123 flats) could be built yearly, meaning that, with afforestation resources, 55 314 homes (42 586 houses and 12 728 flats) could be built each year.

This is 1 203 more than the average new buildings in the past 17 years, according to a statement released on September 28.

Considering both wood chip and afforestation resource potential, close to 95 000 wood-based homes (172% of current supply) could be built yearly.

Crafford says that, excluding imports and current pulp, board and other log resources, there could be an estimated 6.2-million cubic metres of log resources available for wood house components in the future.

“This clearly indicates the resource potential for an increased wood-based construction market in South Africa,” he states, noting that, despite this potential, only 1% of new houses in the country are wood-based, compared with more than 90% in countries such as the US, Canada and Australia.

South Africa’s industrial round wood production, however, is mainly to produce pulp and board products (51%), sawn lumber (24%) and chip exports to Asia. 

Regarding the environmental impact of a wood-based building residential market, Crafford says numerous studies have shown that timber is not only renewable, but is also the best performer across most environmental impact factors when compared with alternative building material such as steel and concrete, with particularly good performance in terms of greenhouse-gas emissions.

“Our basic modelling analyses shows that, if 20% of new houses were to be built with wood, the amount of energy/fossil fuels required for production and the global warming potential of the residential building sector could decrease by 4.9%,” he explains, adding that, if all new constructions were wood based, this could decrease by up to 30%.

“This is quite a significant decrease if one considers that in South Africa, it is estimated that the energy used in the construction and use of buildings is responsible for about 27% of the country’s total man-made carbon dioxide emissions. Wood-based building materials can help to reduce the environmental footprint of our residential buildings.”

However, considering that South Africa does not have a culture of designing and building with wood, Crafford stresses the need for further research that includes other impacts such gross domestic product generation, job creation and social and economic comparisons with regard to an increase in wood-based building.