Putting sustainability into action by building a residential home that serves its environment.
The built industry is an exciting sector, especially as developments and advancements in technology continue to spark the implementation of anything and everything that is new yet practical. Closely aligned to this are the rapidly evolving demands for sustainable and environmentally friendly manufacturing processes and post-consumer practices in terms of products specified.
For these very reasons, it is extremely exciting to investigate and explore local projects that are ‘green’ and sustainable. The end goal of such projects is not only to ensure that current regulations are complied with and certifications achieved, but also that they go the extra mile to ensure that they are playing a prominent role in ‘living’ green and, in turn, setting industry standards.
One such example is the residential home in Lynnwood, Pretoria East, belonging to Nadine Engelbrecht, founder and director of Nadine Engelbrecht Architect (NE). This sustainable project was inspired by its landscape, a mostly undisturbed site that contained a significant piece of rock rising three metres above street level. “The site’s gradiënt and elevated level allows for privacy and phenomenal views over Pretoria,” enthuses Nadine. “The site also borders on Faerie Glen Nature Reserve, therefore key influences to the design included the integration of the house with its surrounding natural landscape. Open-plan design and large glazed openings allow a fluent transition between the interior and exterior and further enhance the views over Pretoria and the nature reserve with its game.”
According to Nadine, she followed the green route in its entirety to ensure a sustainable, low-maintenance and cost-effective construction from the core of the design. “Throughout my design career I have considered sustainability and context-driven design as crucial aspects in architectural design,” she explains.
The following elements were used to achieve Nadine’s sustainable objectives, which she pointed out were designed prior to the new regulations coming into effect:
Passive heating and cooling
The high thermal mass of the stone, brick walls and exposed concrete floors absorb the sun’s heat during winter days and very effectively releases that stored heat during the cold winter nights. Combined with this the limited depth, open plan design and intentional placement of openings the house takes advantage of the dominant wind direction and allows natural cross-ventilation to cool the building during summer months.
Water collected on the roof surface flows into a water storage tank in the basement. This water is used to flush the toilets and irrigate the garden.
Solar hot water heating
The house is fully sustained by solar-heated water requiring no additional electrical heating during summer and most winter days.
Green urban footprint
Small planted balconies are provided on top of the service areas (scullery and storerooms) in order to limit the environmental impact and restore some of the “green” urban footprint. Only indigenous, low-water plants were planted to minimise water requirements. In addition the natural vegetation and rock outcroppings on the street frontage are retained to preserve the natural character of the site.
Local materials and labour were used in the construction as far as possible. For example, stone removed during the excavation of the basement was reused as stone walls and for landscaping. Locally sourced pine planks were used for concrete shuttering and later reused for ceilings and as feature wall cladding.
Natural daylight and artificial lighting
The design allows for optimal natural daylight and by utilising only compact fluorescent and LED lights for artificial lighting at night the energy usage of the building is minimal.
Special storage space was provided in the basement to separate household waste for recycling.
Nadine highlights that she specified polished concrete floors as a continuous finish throughout, comprising 350m² including the garage, concrete stairs, bathrooms, showers, living areas and extending to the exterior patios.
“Polished concrete floors were chosen for their raw, durable qualities,” says Nadine. “Since the structural material becomes the finished product, material waste is reduced, adding to the sustainable benefits of polished concrete as a floor finish.” She reiterates that concrete floors also assist in passive heating during winter months when the exposed concrete absorbs the sun’s heat during daytime and releases the stored heat at night.
In addition, a 15m² pure wool carpet was installed in the main bedroom into a recess cast within the concrete floor. Nadine is of the opinion that the soft-textured carpet generates a warm, welcoming ambience in the private rooms, contrasting with the cool concrete floors of the adjoining public spaces.
Nadine concludes by emphasizing that multiple exposed concrete surfaces make for an extremely difficult construction. “When floors, walls and ceilings are off-shutter concrete, there is no tolerance for mistakes,” she adds. “The details and planning need to be immaculate and the sub-contractors must be well experienced and precise in their practice. All plumbing and electrical work must be done correctly the first time as chasing afterwards is not an option.”
As this unique project clearly demonstrates, sustainability can be effectively achieved and implemented while stringent regulations and/or certification requirements are met. However, this success is dependent on a mixture of creativity, passion and an unwavering belief that the end result will not only serve the occupants, but ultimately the environment too.