Environmental Goods & Services (EGS) News
High performance / green office building - 3 December 2008
Designed by Michael Orchard of New Earth Architecture, this compact new office building in the historically sensitive Dorp st precinct of Stellenbosch, aims to be the first GBCSA (green building council of SA) green star rated building in the Cape winelands.
A previous proposal by a different architect had been rejected by the Heritage/ aesthetics committee of the town for being "boring", as it merely mimicked historical style. It was decided that a bold minimalist-contemporary idiom would be an appropriate design intervention as the building is set back 20m from busy Dorp st, screened by old oak trees, as well as setting up an interesting dialogue or contrast between itself and the surrounding historical buildings. References are made to the vernacular architecture in the white masonry walling, charcoal grey steel and timber sunscreen slats which refer respectively to the old grey thatched roofs and corrugated metal roofs, and timber doors and windows. It was decided to omit the top storey so as to minimise the building's bulk and ensure that the new addition would be sensitive to its venerable cape dutch neighbours.
Many people are starting to use the term "high-performance building" instead of "green building" as they wish to emphasise what is gained from these projects, not what is given up. A high-performance building is one in which energy and water efficiencies are high, indoor air quality is high, recycling rates are high, etc. This is a much easier concept to explain to decision makers than "green building", which still sounds somewhat like tree hugger terminology. High-performance buildings are those that save at least 50% of the energy use of a standard building.
The new office incorporates passive solar design which lessens the buildings reliance on mechanical systems of heating and cooling, leading to energy savings and lower running costs. Door and window openings on the North facade are shaded with timber sunscreens and pergolas to exclude summer sun, but enable solar penetration during the winter months when the sun is lower in the sky. "Thermal mass" is utilised whereby winter sunlight is stored in the walls and floors of the building to be released during the night. The west facade has small openings to exclude late westerly sun in summer.
Natural ventilation & improvement of internal air quality is achieved through the introduction of fresh air through bi-fold doors along the east and southern edges, as well as through a large raised rooflight. These large door openings take advantage of spectacular views over oak trees to the Helderberg mountains, as well as giving occupants access to cantilevered balconies on three sides.
The emphasis on daylighting & natural ventilation has been shown in numerous studies to markedly increase worker productivity & wellbeing, as well as greatly lessen absenteeism due to sick leave.
Construction materials will be sourced within a 50km radius of site as far as possible, to lessen the burning of fossil fuels. Doors , windows and timber sunscreens will be made from recycled and certified sustainably harvested timber. High insulation value glass or double glazing will be utilised on the North and west facades. The roof will be insulated using a recycled eco-insulation (recycled PET plastic) in conjunction with a natural fibre cellulose composite insulation layer, which can in turn be re-cycled or composted at the end of their respective life cycles. Construction waste will be minimised to lessen pressure on already full landfill sites.
Solar vacuum tubes for water heating, are positioned alongside photo-voltaic panels for energy generation , on the roof. Should there prove to be sufficient wind, a vertical axis wind turbine will be added to the renewable energy systems on the roof. Rainwater will be harvested & grey water recycled for use in wc's and for irrigation purposes. Low flow taps, shower head & wc's reduce water usage, whilst highly efficient low energy LED lighting will be utilised throughout to lessen electrical consumption by up to 40% over compact fluorescent lights (CFL). An "electrosense" energy management system will further contribute to electrical savings of between 50 and 80%.
All materials with demonstrated toxicity to humans will be avoided, such as Formaldehyde, heavy metals, PVC etc. Natural fibre carpeting free of VOC (volatile organic compounds) off-gassing will be installed, while all timber will be sealed with natural plant oil based sealers which penetrate and nourish the wood and are non-toxic to the environment and occupants. A natural non-synthetic paint will be specified for all walls, which "breathes" leading to a healthier indoor air quality and humidity control.
Finally, the covered parking area is to be paved with permeable pavers, thereby lessening stormwater runoff to the street, stormwater drains, rivers and ocean often contaminated with grease and oil.
New Earth architecture are also currently designing a guest house for the Sustainability Institute in Stellenbosch, which will be constructed using rammed earth technology, as well as a new green residence in Tulbagh, and an eco-house in Noordhoek making extensive use of Hemp fibre as a rapidly renewable resource, alleviating resource depletion.
For more information contact:
NEW EARTH architecture
Michael Orchard : 084-707-7700
Sandy Adams : 082-533-3177