Let’s Talk NET ZERO CARBON

GBCSA’s technical team weighs in on net zero carbon – what it means, why it matters, and how local buildings are stepping up to meet it.

The journey towards net zero carbon in the built environment is something that I am personally very passionate about. I’m delighted to share that passion with you in this article.

GBCSA’s suite of Net Zero rating tools is proudly built on African soil, for an African construction sector, and we are starting to see exciting results from the local developers who’ve stepped up to its standard.
But what does net zero carbon really mean for a building? And why are we working so hard to achieve it?

Defining Net Zero Carbon

In simple language, net zero carbon means that when a project is measured over some time, say a year, the sum of all its carbon emissions – and the actions that it has taken to remove carbon from the atmosphere – should equal zero. The negatives, like using energy from a coal-powered grid, are balanced by the positives, like energy generated from renewables.

Net zero carbon traditionally refers only to the operational phase of a building’s lifecycle. In other words, the energy used to keep the lights and air-con on. In reality, however, carbon is also generated in the construction phase of a building. For example, the concrete and steel used to build tall offices require energy to be manufactured and transported to site. To account for the whole life carbon impacts, we use a holistic approach, where both carbon emissions from operation and the embodied carbon from construction must be accounted for. This sets a stiff challenge, particularly in countries like South Africa with a national grid currently so dependent on coal.

To avoid the idea of net zero carbon becoming a “castle-in-the-clouds” concept, reserved only for elites, GBCSA has provided industry with clear pathways, aligned with international best practice. Because we believe that South Africa’s green story is everyone’s story, we use a stepped approach to net zero.

This approach starts with pursuing energy efficiency as the first principle. Energy efficiency is something that all projects can and should be targeting. It benefits everyone, from the REIT looking to increase the net operating income of its portfolio of offices, to the social housing resident looking to reduce the cost of utilities. It’s the first step on the net zero pathway for a reason!

The next step or pathway option is reviewing opportunities to generate renewable energy on site, typically done with solar PV (and thermal solar water heating for residential or hospitality applications). However, most tall buildings in our city centres have limited roof space to meet their operational demands, and hence there is a technical limit to how much on-site PV will help them reach net zero carbon.

For the energy needs that can’t be met on site, off-site renewable energy can be considered. Given South Africa’s energy supply reality with Eskom, the recent wheeling opportunities and IPPs greatly benefit this pathway, which will need to be used by most commercial buildings.

Finally, to close any remaining gaps, sustainably sourced offsets can be explored to take a building to true net zero carbon champion status. Carbon offsets are seen as the last resort, once all other options are fully explored, to support the transition to net zero carbon. For GBCSA, it is a requirement that any carbon offsets come from trusted and third-party accredited sources.

Why Net Zero Carbon matters

The built environment, through construction and operation, contributes approximately 37% of the planet’s greenhouse gas emissions.¹ It’s also one of the most effective sectors, rand for rand, to spend on to reduce emissions, as identified by the Intergovernmental Panel on Climate Change (IPCC), the World Resources Institute (WRI), and South Africa’s own Greenhouse Gas Mitigation Potential Analysis.² As such, buildings, as a sector, are positioned to lead climate action and deliver scaled solutions. The question is how to support the sector in doing this?

This is the value of the accessible net zero carbon pathway. It supports spending on emissions mitigation in one of the most critical and most effective sectors, and it starts with a focus on energy efficiency, which is supported by such a clear and intuitive business case, no matter the type or scale of project.
This is how GBCSA sees climate transformation in the built environment: clearly incentivised and universally relevant, moving forwards, sometimes incrementally, but always together.

There is a cost to moving too slowly, however. Net zero carbon buildings, as a share of total buildings and of new buildings, are critical climate-change mitigation milestones. Internationally, the Paris Agreement, which South Africa is a signatory to, uses data-driven models and predications to determine the emissions reduction we need to limit warming to 1.5°C.

If we don’t reduce emissions in line with these goals, we have a much better chance of a higher temperature increase. This would be disastrous for the planet, but especially for us in Southern Africa, who are expected to experience warming at twice the average rate. There are several excellent sources of research that detail what we are likely to face locally as temperatures rise.³

In a nutshell, we can expect an increase in extreme weather, a decrease in agricultural yield, changing microclimates and biodiversity loss. What this would mean for us is huge costs in loss of life and damage to property from storms and floods; a hit to economic growth and a rise in poverty and hunger; diseases like malaria spreading beyond their usual reaches; widespread health effects from heat and drought; and ecosystems that have played a role in tourism and other industries being lost forever.⁴ By being complacent around emissions reductions, we are almost choosing this future.

Climate action might feel like it makes doing business hard right now, but the impacts of inaction will make doing business infinitely harder.

How are we stepping up?

The Paris Agreement clarifies ways that we can act. Globally, one of the goals for the built environment is to aim for all new buildings to be net zero carbon by 2030, and all buildings to be retrofitted to net zero carbon by 2050. Globally, we remain quite a distance from these goals.⁵

That’s where the net zero pathway concept comes in. Since the Net Zero rating tool was introduced by GBCSA in 2019, we have seen local developers pioneering processes, products and perspectives to achieve it.

Over time, the numbers show that more and more buildings are grappling with their emissions profile, targeting first energy efficiency, then renewables, to achieve buildings that meet their own needs and mitigate their own impacts. These buildings are focused on energy balance within the operational phase, rather than the complete carbon picture, but they are our trailblazers; tangible demonstrations that good action is possible and happening!

Some of the buildings whose stories have most excited me are:

1. Green Barn at Greencreek – a lifestyle centre within a residential estate, this building combined world-class energy efficiency, achieved through detailed modelling, with renewable energy to achieve its net zero certification. Read more at the GBCSA project directory here.
2. Headquarters of Fuchs Lubricants – this office building boasts a 100% electrification strategy that eliminates its Scope 1 Carbon emissions (see +Impact issue 21).
3. Bracken Nature Reserve Visitor Education Centre – a public building that tells the story of Cape Town’s Bracken Nature reserve, this structure relies on cutting-edge passive design to eliminate all of its cooling needs and meet the remainder with an on-site photovoltaic system (see +Impact issue 25).

Their stories are our lighthouses, showing us what we can achieve, and marking the way forward for future projects to take net zero even further.

We’re also in the process of taking our Net Zero tool further. Much has changed, here in South Africa, and across global construction markets, since its 2019 launch. It’s time for us to bring it line with cutting-edge research, new best practices, and the urgent climate ambitions of a warming world. Watch this space, and GBCSA’s website for updates.

I’d like to end off with an invitation. The most important thing, and sometimes the biggest mental challenge, in any journey is the first step. Whether you are a regular green certifier, or considering certification for the first time, and whether your project is an office park, a public building, or a residential estate, we at GBCSA would be honoured to start you on the net zero path towards a sustainable climate future.

References

1. https://www.unep.org/resources/report/building-materials-and-climate-constructing-new-future
2. https://www.dffe.gov.za/sites/default/files/docs/mitigationreport.pdf
3. https://cer.org.za/wp-content/uploads/2021/09/Climate-impacts-in-South-Africa_Final_September_2021.FINAL_.pdf
4. https://web.csag.uct.ac.za/~cjack/South%20Africa_FINAL_22%20Jan_ONLINE.pdf
5. https://www.wri.org/insights/climate-action-this-decade-sectoral-emissions