TAKE A LOOK | SA engineers have built a 'living breathing building-organism'
- The Ridge commercial office development which has just been completed in the V&A Waterfront in Cape Town, features several 'firsts' for the green building and sustainability industry in South Africa.
- From a centralised core which was built to mimic the ventilation of an anthill, to timber and eco bricks, it has some surprising innovations.
- We got an exclusive tour to see how it works.
- For more articles, go to www.BusinessInsider.co.za.
A new Cape Town office block is one of the greenest buildings in Africa - its designers have dubbed it a “living breathing building-organism”.
The Ridge commercial office development, which has just been opened at the V&A Waterfront in Cape Town, has made full use of African inspired innovation.
What was previously a parking lot is now the home of accounting and consulting firm Deloitte and features several 'firsts' for the green building and sustainability industry in South Africa.
“We believe that this is one of the most unique green buildings in Africa, if not the world. This has been a fascinating journey for us, supported by Deloitte, who subscribe to sustainable and green building, and actively promote the United Nations' Sustainable Development Goals.” said Mark Noble, Development Director at the V&A Waterfront and project leader.
The building follows what its designers call biophilic architecture design - that connects building occupants more closely to nature through design. Its designers have built it to encourage occupants to open the windows and let the natural air and light flow through, instead of locking the air in behind glass and concrete.
“What we are trying to do is create a relationship with people and nature. We don’t want to run the air conditioner and live in an industrial glass fishbowl building that tries to keep the temperature at a steady 21 degrees when its freezing or hot outside,” said Sean Mahoney, owner of architecture urban design firm StudioMAS that helped design the Ridge. “By maximising natural light and temperature control we can reduce our impact on the environment.”
Among the innovations used in the building are eco bricks made from discarded plastic, which were sourced directly from trash in Cape Town; a specially designed centralised core which was built to regulate the temperature like the ventilation of an anthill; as well as making use of South African timber inside and outside the building to keep it cool.
The building was awarded a 6 Green Star Office Design rating by the Green Building Council of South Africa (GBCSA) and features a number of South African firsts for commercial building design, said Tessa Brunette, architect and building envelope designer at Arup Buildings group (engineers involved in the buildings eco-friendly design).
“We used South African pine, a cheap and sustainable material, sourced from certified plantations in George for the interior of the building. There is a special cavity of space between the internal and external wood which helps to keep the building cool. Over time the external façade is going to turn silvery grey as it was treated with a special Akoya treatment that heats all the sugar out of the timber, to prevent the bugs from being attracted to it.”
The sustainability measures could result in savings on utility bills of between R12–R18 per square metre per month for the 8,500m2 building.
Business Insider South Africa took an exclusive tour inside the building to see some of the cool things it does, here’s what we found:
The building breathes on its own.
The building is a 'living breathing building-organism'. A 16-metre-high atrium provides a chimney effect from the first floor, drawing air through 6 operable roof drums. The drums open and close automatically according to the ambient temperature in the building. During summer they will open for longer periods and during winter they will stay closed and keep the air in.
This enables temperature control inside the building much like the central column of a termite’s nest.
While most buildings try to keep air in, the Ridge wants its tenants to open their windows with a stop/go light system.
A light system advises employees whenever it is possible to open the windows to allow in the outside air in -which will naturally keep it cool. When the lights flash red, the building wants its tenants to keep the windows closed. If it goes green it means they can open them.
Blinds will also automatically close if the building sensors pick up too much direct sunlight entering the building. Tennants can override the system and lower them further for a period of an hour before it reverts back to its automatic state.
The building can operate in two modes. As a conventional sealed air-conditioned building or alternatively in a passive naturally ventilated mode in favourable weather conditions. When they do use aircon, they send it upward through holes in the flooring.
The air conditioning for the building is distributed in the void beneath a raised access floor. It circulates and then trickles upwards at low levels. This system allows for the air to require far less energy to heat and cool and requires far less energy to pump through the building.
To regulate the building temperature, it uses water pipes in the ceilings through a TABS system.
The building has a thermally activated building system (TABS) installed. It uses water pipes embedded within the concrete to regulate temperature by heating and cooling the actual building mass. With TABS operational, the natural ventilation potential inside the building is increased to between 75% and 88% of the occupied hours in the year, which represents a huge saving on air-conditioning operational energy costs.
It has a pinewood façade that zigzags to help with climate control.
A standout feature of The Ridge is the saw tooth ‘Zigzag’ exterior timber cladding. This is the first time cross-laminated timber (CLT) has been used in the façade of a commercial building in South Africa.
Extensive thermal modelling was undertaken by the engineers to determine the exact angle of the "saw tooth" design for the façade and the most favourable glazing solution.
South African pine timber was used to ensure strength, stability, and longevity. The designers say using timber lowers the carbon footprint more so than any of the other traditional cladding systems, including aluminium, glass, concrete and brick.
The Ridge harvests rainwater...
Built into the building's garage are rainwater harvesting tanks.
...and makes use of renewable energy.
The roof will harvest up to 150-160 kW of solar photovoltaic power via the placement of 461 PV panels on the roof facing the optimum direction. The overall building plans are for a 750 kVA power requirement and the PV power will be grid tied, but not expected to feed back into the grid. A backup generator in the basement will actively trigger when there is load shedding.
They used 12,000 ecobricks made from upcycled plastic as ‘void filler material’ replacing some 24,000 litres worth of concrete.
While you may not see it now, 12,000 ecobricks were used as void filler to take up the empty floor space of the central toilet areas of the building.
The ecobricks are made in 2 litre plastic bottles that were stuffed to the brim with discarded plastic collected from chip packets, candy wrappings, shopping bags and waste generated on site.
The result means 5.2 tons of plastic was upcycled into the building rather than seeing it go to landfill.
The ecobricks were sourced from actual waste collected by 4 local community projects in Cape Town. According to the project team, this is the first time a major construction has incorporated ecobricks in this way.
"Often, builders incorporate void-forming materials into concrete slabs. These are of a much lower weight than concrete. They are sometimes made of expanded polystyrene (EPS). Under normal loads, these voids do not undermine the structural strength of the slab. But they offer many other benefits, which is why we use them,” said David Green, CEO of V&A Waterfront.
The overall design has been influenced by best-practice examples of commercial office buildings such as Google, BskyB in London and Co-Op in Tokyo.
According to Marius Alberts, regional leader at the Deloitte office in Cape Town, the building also utilises the same technology as is used in their Edge building in Amsterdam South, one of the highest rated green building in the world, to make the Ridge even more efficient.
"The Edge building uses IoT connectivity to optimise its energy efficiency and promote employee mobility and wellness goals. So we incorporated this approach into our new office at the Waterfront Ridge,” said Alberts.
The block received a 6 star Green Star Office Design rating by the Green Building Council of South Africa (GBCSA) – one of only 9 given to buildings in SA.
“Six-star ratings are unusual in SA and is not an easy achievement for a design rating. Only nine other offices have achieved this accolade to date, either through our Design or As Built rating, or both, since 2010. It involves a committed client, a dedicated professional team and an integrated design approach by all” said Lisa Reynolds, CEO at the Green Building Council of South Africa.
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