Five must-know terms associated with sustainable housing

Sustainable building

With an ever-increasing focus on sustainability in all aspects of development, the conversation is well and truly underway. To fully grasp the concept, an understanding of some of the terms used most frequently is helpful. If you’re a beginner, here are five terms that could be of immense help to you.

Green building

A green building is a carefully designed building that minimizes site disruptions, uses energy and water more efficiently while providing greater levels of thermal and visual comfort to occupants. It focuses on minimizing environmental impacts during its construction and operation. It also reduces the energy needed to operate it by incorporating daylighting and passive heating, cooling and ventilation. What’s more, a green building seeks to generate less waste, and recycle/reuse some of the waste generated, both solid and liquid.

Net-Zero/ Nearly-Zero energy building

A Net-zero energy building is a building that produces all the energy the building needs for operation on-site from renewable sources. In some cases, the energy produced by a Net-Zero energy building is more than what is required to operate the building. This excess energy is then exported to the regional/national grid.

A nearly-zero energy building is a building with a very high energy performance such that it requires very little energy to be run. This very low amount of energy (nearly zero) should be supplied by renewable sources, whether this is generated on-site or off-site.

HVAC System

HVAC stands for Heating, Ventilation, and Air-Conditioning. It involves all mechanisms that are required to enhance thermal comfort of users in a building. This could be natural, like openings or through the use of blinds, curtains, etc. They could also be mechanical, in the form of heat pumps, boiler or furnace based heating systems, chilled-beams, air-conditioning systems, and cooling towers.

Life cycle assessment

This considers the entire lifespan of a building, from cradle to grave. It starts with the design, site selection, construction, operation and maintenance, renovation, and demolition. A life cycle assessment could be done in respect of the cost of the building (life cycle costing), or the economic benefits or savings that a building could bring. Sometimes, a life cycle assessment is done on the building materials to be used for the construction.

Grey & black water

Greywater refers to wastewater from bathing, washing, and water from wash hand basins. Blackwater consists of wastewater from the toilet and sometimes from the kitchen sink. One key mechanism for managing wastewater on-site is the installing of a trap in the plumbing system. These traps contain water which prevents foul air from moving back into the appliance.

Greywater re-use is encouraged after it is recycled and treated. For obvious reasons, the same level of enthusiasm is not given to black water. Depending on the quantity generated, some form of treated is first carried out on-site before being it is finally discharged into sewage systems.

So there you go. By no means is this list exhaustive. But it is certainly a good primer for the uninitiated. What other points do you think were left out?

Photo by bantersnaps on Unsplash

Boat Sekyere

Boat Sekyere

Boat is a valuer fascinated by sustainable urban land use planning. He was recently selected as a Local Pathways Fellow of the UN Sustainable Development Solutions Network (SDSN Youth) - a global Fellowship of 128 young leaders who will champion SDG 11 in their cities. When he's not reading another e-book, he's out photographing an event (@rsbpictures) or cycling in his hood, binge listening to his favorite podcasts. Say hi at

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