PAVING THE WAY towards higher sustainability standards
Conveniently located in Midrand, Gauteng, The Precinct Luxury Apartments development is changing both the market and the mindset of middle-market residential tenants, one unit at a time. When the project started between 2017 and 2018, it soon became clear that only a few minor changes were needed to achieve EDGE (Excellence in Design for Greater Efficiencies) Advanced V2 certification – and the rest is history. The first four phases of the project, consisting of 1 388 units, boast 41% energy and 37% water savings, and the materials used demonstrate 35% less embodied energy.
It’s built for rent, enabling the owner to ensure that the project stays its course. “Our teams understand what is going on inside the units, and as tenants move out and in again, the teams do a thorough check of the status of the unit,” says Douglas Eva, Site Operations Manager at Century Property Developments. “If all those units were sold, and different owners were doing different things inside the unit, it would be a lot less manageable.”
EDGE Auditor and owner of Inside Out Consulting Yvonne Pelser highlights other challenges typically faced with these types of developments: “Energy usage is mostly at night, the number of solar panels are limited for optimum efficiency, and battery systems are not ideal, due to their complexity in apartment buildings.”
Century Property Developments decided to take these challenges head on – and although The Precinct Luxury Apartments is rated under the previous EDGE version, the project is constantly evolving, and even drives market transformation.
To achieve EDGE Advanced V2 certification, the project had to demonstrate minimum energy savings of 40%, minimum water savings of 20% and at least 20% less embodied energy in materials. It took time, and a higher initial expenditure. “You must really work through your design, unit by unit,” says Quantity Surveyor Executive at Century Property Developments, Japie Vos. “Get everyone – your architect, your XA calculations expert [SANS 10400 XA is the South African National Standard regulating energy efficiency in building design], your electrical consultant – to sit with the EDGE expert. Look at all the elements and do the small tweaks on specifications. You must go through the design development to get here.”
Here is how they did it:
41% ENERGY SAVINGS
Reducing energy usage was achieved through specific design processes and structural elements. It included a reduced window-to-wall ratio of 17.78% which, according to Pelser, compares well with the EDGE base for the middle-market segment (30%). The roofs are insulated with cellulose, consisting of 80% newsprint waste, and internal spaces are fitted with LED lights. But what happens when the globes or other added elements break? “We have well-equipped maintenance teams for each development, with a very good understanding of the specs of all the fittings, to keep tenants from performing maintenance themselves,” says Eva. He adds that the teams have access to a warehouse that stocks a large amount of all the different elements required in the buildings, so maintenance teams can pull stock when something needs speedy replacing.
Power is supplied via a 428.4kWp PV system, mostly placed on carports and rooftops, and generates 16% of the total energy used, providing each of the 1 388 units with 0.3kWp. Solar power also plays a big role in the combined methods of water heating.
The first phase of the development was fitted with electric geysers and dedicated solar panels. In phase two, heat pumps with a COP (coefficient of performance) of 3.45 were installed. In phase three, a pre-heating solar system was added to the heat pumps to ensure water is heated before it is sent into the system, culminating in a combined average COP of 4.
All these energy-efficient initiatives and designs are tied together with smart metering, to which tenants have access. It forms part of the billing system for electricity and water, which is displayed on a tenant’s mobile application, so they’re able to monitor their own consumption. “The landlord also benefits from this,” says Pelser. “It can help them identify leaks, overcrowding, tampering and other problems. So, by monitoring the peaks and the troughs, you can see if there are any issues in the way the building is running.” Eva and Vos add that the collection of data helps inform better decisions at each phase – citing the water heating system as an example where notable changes in energy consumption are visible. “There’s better efficiency from an energy point of view, it reduced capital expenditure on installations and it’s an easier installation,” elaborates Eva.
Pelser highlights another contributor towards energy saving: “Sustainable water use is linked to electrical consumption because a lot of the water you use in the shower is hot, which requires electricity. So water flow rates, for example, can also help reduce your electricity consumption.”
37% water savings
Low-flow showerheads and tap fittings in both kitchen sinks and wash basins aided this achievement. According to Pelser, Hansgrohe taps, already fitted with restrictors from the factory, helped the team go beyond the EDGE base case flow rate. “Showerheads run at 5.7 litres per minute, in comparison to the base case of 10 litres per minute. Kitchen taps run at 7 litres per minute as opposed to 8 litres per minute, and bathrooms taps compare at 5 litres per minutes to the base case of 8 litres per minute.
Another prominent water saving feature is the dual-flush water closets, and installation of Geberit Abalonas in lavatories. “The base case is 8 litres on the first flush, and six litres on the second flush,” says Pelser. “Here, it’s 4 litres for the first flush, and 2.6 litres for the second flush.”
35% less embodied energy in materials
Although many materials used throughout the project only meet the base case requirement, they have been carefully considered with the future in mind. According to Vos, the long-term lifecycle cost of the project plays a key role in sustainable developments because “the higher your maintenance cost, the higher your lifecycle cost”.
Aluminium window frames are a base case requirement, explains Pelser. They are, however, most suitable in the long run considering the harsh Gauteng climate, resulting in what Eva describes as a “maintenance nightmare” – wood would have to be treated almost biannually. Along with that, cored face brick has been used throughout the different phases, also meeting the base case requirements. “The creation of face brick uses less material and it’s lighter to transport. You don’t have to worry about plastering it when there are cracks, and you don’t have to repaint it,” says Pelser.
The residential blocks are all four storeys high, some with internal lofts. The floors consist of 150mm hollow-core precast slabs, topped with porcelain, which complies with the base case, but again, Pelser maintains this kind of flooring is more durable from a long-term maintenance point of view. The roofing pushed some boundaries. Instead of the base case of concrete, timber rafters were used, covered by 0.5mm steel sheets. Although steel is generally considered a less ideal material of choice, Pelser says it was considered and utilised owing to it durability and thinness.
Going the extra mile
The buck doesn’t stop at meeting EDGE Advanced V2 requirements, says Pelser, who describes the developers as being highly pro-active. This is evident in the constant evolution throughout various developments, and some of the spill-over effects that weren’t necessarily considered in the official certification. Their choice of skirtings, made of recycled materials, helped encourage market transformation. Eva elaborates: “When the company came to us, it cost more than timber, but because we needed such large quantities, the company we purchased it from has now expanded with an entire range of different skirtings and products. It’s grown in size as a company, and the price of its recycled material skirtings is now lower than that of timber.”
In addition, Century Property Developments is considering the certification of other projects, including schools and a distribution centre, slowly but surely paving the way towards a more sustainable future.