Redefine’s ambitious goal of achieving Net Zero across its entire portfolio started with a pilot project involving three existing buildings, namely 2 Pybus and 90 Rivonia in Sandton, and Rosebank Link in Rosebank. These were built several years ago and already have Green Star New Building Design and As-built ratings as well as Existing Building Performance (EBP) ratings. These three Redefine buildings are the first in South Africa to achieve a Net Zero Carbon Level 2 certification based on actual measured energy consumption data during operations.

Rosebank Link

Says Anelisa Keke, chief sustainability officer at Redefine:

Being certified as net zero provides an objective confirmation to our key stakeholders that our certified buildings have been benchmarked against global best practice efficiency standards. A sound climate change resilience strategy ensures that our capital investments are safeguarded against manageable climate risk exposure and create long-term value for our key stakeholders.

We will take the successes achieved from these three buildings to enhance energy efficiencies broadly across our portfolio, which benefit Redefine and its tenants, in line with our purpose to create and manage spaces in a way that changes lives.

90 Rivonia Road

What does Net Zero Level 2 (measured) mean?

Marloes Reinink reveals more about the Net Zero certification process:

Let’s start with the GBCSA’s definition of a Net Zero Carbon Building:

A building that is highly energy-efficient, and the remaining energy use is from renewable energy, preferably on-site but also off-site where absolutely necessary, so that there are zero net carbon emissions annually (Net Zero).

The Net Zero Carbon Certification is categorised into five different levels of which only two are currently open for certification, with the third certification level (Embodied Carbon of Construction Materials) being developed.

90 Rivonia Road

Level 1: Building Emissions (Modelled)

This level is for buildings that are in the design/construction phase; it covers the base building energy consumption (excluding tenant loads) and is calculated through a simulated model. This certification is for developers/owners who want to market their building as Net Zero early on in the design/construction process. Tenants must be aware that the tenant load is not included in the calculation. Certification is valid for three years, after which the certification must be renewed as Level 2 (Measured). This certification encourages building owners/developers to design their buildings with energy efficiency in mind and allow for on-site renewables.

2 Pybus Road

Level 2: Base Building Emissions + Building Occupant Emissions (Modelled OR Measured)

This level covers the entire building consumption including tenant energy consumption. This can be done during the design/construction phase through simulation modelling OR based on actual operational consumption figures (measured). The measured route is the ultimate certification you want to achieve if you have Net Zero ambitions – this is the real deal.

2 Pybus Road

How do you do it?

A three-pronged approach was adopted: firstly, improving energy efficiency in the buildings, secondly, maximising renewable energy opportunities, and finally, as a last resort, resorting to carbon offsetting through the purchase of carbon credits.

The Redefine buildings are existing buildings that achieved Green Star ratings in the past, demonstrating that they were designed to be green buildings and energy efficient. In order to get them Net Zero certified, Solid Green followed the following steps:

1. Assess the current energy consumption: we requested 12 months of energy data (electricity and diesel) from the facilities team at Redefine. We analysed the data and calculated the kWh/m2/annum and ranked the three buildings in terms of energy efficiency.
2. On-site renewable energy: we deducted the solar energy that was generated by the solar panels installed on the buildings.
3. Off-site renewable energy: because wheeling or feeding back into the grid is currently not a solution in Johannesburg, we could not make use of any off-site renewable energy generated. This is however a strategy of Redefine’s in the future, and we might be able to include this in year 2 of the certification.
4. Carbon Offsetting: this includes the purchase of carbon credits for the remainder of the energy. The Net Zero certificate notes the percentage that has been offset via carbon credits: 2 Pybus Road 11.5%; 90 Rivonia 56.3% and Rosebank Link 32.9%. Considering these are large commercial office buildings, this is a good achievement.

What’s next?

Redefine has achieved the offset for the first year and committed to maintaining the certification for the next three years, after which the evidence must be submitted to the GBCSA for re-certification. So, in the coming year, Redefine is focussed on further improving the energy efficiency of the buildings (Step 1 above), as well as exploring off-site renewable energy (step 3) through wheeling, which looks like a very promising opportunity.

Redefine is committed to defining their Net Zero pathway to guide their business approach towards transitioning to a low-carbon economy. Their strategy focuses on assisting their tenants to reduce grid-based energy consumption and cost, and on improving renewable energy generation for self-use. These three Net Zero certifications were part of an exciting pilot study with the intention to include more buildings in the near future to support a low carbon economy.