The concept of ‘green buildings’ is increasingly a topic of conversation, in line with the move to more environmentally-sustainable practices in our daily lives. A direct link exists between buildings, carbon emissions and the ability of the natural environment to absorb carbon dioxide. Globally, the built environment uses a substantial percentage of resources: 40% of energy, 17% of fresh water, 25% of wood harvested and 40% of material.
People often underestimate the environmental impact of buildings, while overestimating the perceived costs of green buildings. Reducing the amount of natural resources that buildings consume and the amount of resulting pollution is seen as crucial for future sustainability. And sustainability is central to green buildings.
But what does it take for a building to be green? Basic questions to ask in determining whether a building is green include: Does the building reduce its impact on the natural environment? Is it recyclable or re-usable? Does it improve the indoor environmental quality? Is it resource efficient and effective?
A building qualifies as ‘green’ when it is designed to make efficient use of resources such as energy, water and materials. Its impact on human health and the environment during the life cycle of the building is also taken into account. This is addressed through better design, construction, operation, maintenance and removal.
During construction, green architecture is geared towards reducing the waste of energy, water and materials. One should aim to reduce the amount of material going to landfills; well-designed buildings also help to reduce the amount of waste generated by people, for example, by incorporating the practice of compost bins.
Effective green buildings can:
- reduce operating costs by increasing productivity and using less energy and water
- improve people’s health through better indoor air quality
- reduce environmental impacts by, for example, reducing emissions..
Green rating system
The Green Building Council of South Africa aims to lead the transformation of the South African property industry to ensure that buildings are designed, built and operated in an environmentally-sustainable way. The council has introduced a rating system, which enables one to measure objectively how green a building is. The South African rating tool is based on the Australian Green Star system, customised for South African use.
The rating system sets out a ‘menu’ of all the green measures that can be incorporated into a building. Points are awarded to a building according to which measures have been incorporated, and after appropriate weighting, a total score is given that determines the rating.
SA’s first Green Building Handbook
To provide practical and applicable content and information for built environment professionals who want to build ecologically-sensitive buildings, Green Building Media launched South Africa’s first Green Building Handbook in 2009.
CSIR researchers contributed 12 of the 14 chapters in the handbook. Edited by Llewellyn van Wyk of the CSIR, the Green Building Handbook 2009 provides readers with practical insights into green building designs, technologies, materials and solutions relevant in the South African context, and their effect on the environmental impact of buildings. See extracts from the various chapters.
Green building materials
Energy in green buildings
||The construction industry is a multi-billion Rand industry, and the production and harvesting of raw materials for building purposes occurs on a world-wide scale. The environmental performance of the construction industry is coming under close scrutiny, particularly with regard to the availability and sustainability of certain materials, and the extraction of the large quantities needed.
Indoor environmental quality
||Legislation in South Africa will in future require buildings to be more energy efficient, with new standards on energy efficiency being developed by the South African Bureau of Standards (SABS). Some municipalities are looking at by-laws and incentives schemes to reduce energy consumption in buildings.
Water use in green buildings
||Indoor environmental quality (IEQ) refers to the environmental quality within a building, focusing specifically on the health and comfort of the occupants. This generally includes air quality, thermal comfort, artificial lighting and day lighting.
Large volumes of water are used in buildings on a daily basis. To enhance the green status of buildings, efforts should be made to develop water systems for water conservation. In South Africa, there is a move towards water-efficient taps and dual-flush toilets in new buildings, but we have much catching-up to do.