Reliance on fossil fuels to power our buildings and cities is damaging the health of our people and environment, but this can be overcome with a move to net-zero carbon buildings. They are completely viable today and crucial for the future.
The GBCSA defines a net-zero carbon building as “a building that is highly energy-efficient, with the remaining energy requirement generated
from renewable energy, preferably on-site, or off-site where necessary”.
The critical mass of net-zero carbon buildings is required to meet political and planetary climate goals. The built environment currently produces one-third of the world’s carbon dioxide emissions. This sector must drastically reduce the amount of CO2 it generates and it has the potential for significant greenhouse gas emissions reduction at a lower cost than other sectors.
It is possible and imperative for us to achieve net-zero carbon buildings, and with determination and enabling building standards, policies and legislation, it can be implemented far and wide.
The biggest challenges facing the uptake of net-zero buildings are those of perception (when people think it’s more difficult than it is), technical challenges as well as financial challenges. All of these are being
The main aim when targeting net zero is to drive the energy consumption of a building as low as possible. This is done by addressing the main consumers of energy such as heating, cooling, lighting and equipment.
Using passive design strategies that work closely with the prevailing climate and context, not only helps to create comfortable buildings for people but also ones that are energy efficient.
Building performance simulations make it easier than ever today to understand and predict the way a building will operate, allowing us to intervene and ultimately design and construct the best spaces possible. Once simulations and cost-effective passive design interventions have driven energy consumption from heating, ventilation and cooling (HVAC) and lighting as low as possible, advances in technology can be used to ensure that the active equipment required in the building is as energy efficient as possible with the use of on-site renewable energy.
If this cannot be achieved on-site (for example in buildings with limited roof-space in relation to floor area), then off-site renewable energy can be explored.
With the focus on new and existing commercial buildings, mainly offices, with some reference to the residential sector, the guide provides useful efficiency targets to aim for and offers guidance and practical tips on how to achieve them – from identifying the right people to have on your project team, to the actual energy-use intensity of lighting and mechanical equipment that should be targeted in a commercial building. Furthermore, it highlights renewable energy considerations to bear in mind on your project.
The guide features numerous case studies, showcasing projects that have already achieved net-zero carbon status. These projects inspire and share learning to motivate those seeking to make net-zero carbon a reality.
It also emphasises that building energy-use intensity should be about one-third of current standard practice in South Africa and details the most effective passive design strategies to use in the local context. And when implementing active systems such as air conditioning, it gives the pros and cons of different systems and guidance on choosing the most effective ones for particular regions in South Africa. Finally, the guide highlights some of the intricacies of the renewable energy landscape in our country.
ASHRAE South African Chapter (American Society of Heating, Refrigerating and Air-Conditioning Engineers). This is a volunteer-based society of built environment professionals, striving to improve and share building sciences and related industries.
C40 Cities Climate Leadership Group (C40) South Africa Buildings Programme. Connects 96 of the world’s greatest cities to take bold climate action, leading the way towards a healthier and more sustainable future. Representing 700+ million citizens and one-quarter of the global economy, mayors of the C40 cities are committed to delivering on the most ambitious goals of the Paris Agreement at the local level. The C40 South Africa Buildings Programme is delivered in partnership with Sustainable Energy Africa (SEA). It includes embedded expert advisors working in each city, to develop net-zero carbon building policies and bylaws as part of a roadmap to achieve net-zero carbon new buildings by 2030.
The Green Building Council South Africa (GBCSA). Promotes sustainable development and property industry transformation through green building programmes, technologies and design practices. The GBCSA has developed comprehensive environmental rating systems for buildings, including Green Star, Energy Water Performance and Net Zero/Net Positive.
The guide to developing net-zero carbon buildings in South Africa