22 – March/April 2012 – EnvironmEntal managEmEnt

SuStainable conStruction

CapeNature’s flagship tourism facility, the Oudebosch cabins at Kogelberg Nature Reserve, was launched in early February 2012. The reserve, known for its extraordinary botanical wealth and endemism, is considered to be the heart of the Cape Floral Region which is a World Heritage Site – and with its history of previous good management and declaration as a reserve in 1987, its floral wealth has been protected. The Kogelberg Biosphere Reserve of which the Nature Reserve is the ‘core zone’ was the first biosphere reserve to be declared in southern Africa and is part of UNESCO’s world-wide network.

An element of CapeNature’s Tourism Strategy is the commitment to environmental best practice in all new tourism developments and upgrades. This involves the avoidance or mitigation of negative impacts, while optimising the use of ‘green’ building technology. Oudebosch received an Acknowledgement Award at the 3rd International Holcim Regional Awards for sustainable construction with architectural excel-lence at a public ecotourism facility, for designers Justin Cooke and Jessica Cohen of Architecture Co-op.

The judges’ citation was as follows: “The Kogelberg Nature Reserve is home to the most complex biodiversity on the planet and as a con-textualised feature Oudebosch is a commendable example of good practice – balancing tourist needs and preservation aspects. The project offers a thoughtful approach to building design and showcases durable, recyclable and renewable materials, and through energy-efficient design extrapolates the visitors’ experience of the reserve to the structural level”.

Biosphere reserveThe biosphere reserve concept incorporates local communities, farmers, conservation agencies and local government in the protection of priority landscapes and biodiversity. Sustainable utilisation is key to a biosphere reserve. Such reserves which comprise three zones aim to unite and benefit both the natural environment and communities living in and around it. The Kogelberg Biosphere Reserve is some 100 000ha in extent and reaches from the sea to the mountain tops, with the highest peak at 1 265m.

The core zone which in this case is Kogelberg Nature Reserve is an undisturbed, biologically rich and legally protected area. The biological diversity is conserved but recreational activities that do not impact heavily on the environment, and

educational initiatives and research, are acceptable in this zone. Visitor numbers need to be limited. Recreational activities at Kogelberg Nature Reserve include trails for hikers at several levels of fitness; kayaking during the winter season on the Palmiet River for competent kayakers; tubing and rafting excursions on the river; and two mountain biking routes.

The buffer zone of a biosphere reserve comprises less ecologically sensitive but still mostly natural areas where sustainable use activities may occur – here the combined efforts of land owners are crucial to achieve the buffering function. The transition zone allows a variety of more intense land uses but there is need for the building of a conservation ethic within communities and activities need to be undertaken with ecological

processes in mind. Sustainable conservation cannot happen

without the involvement of local communities and the Kogelberg Biosphere Reserve has invested ±R 3,5 million in employment opportunities for the surrounding local communities. This has funded such activities as alien plant clearing, firefighting, footpath and road maintenance and cleaning, as well as the provision of gate services at the reserve. The reserve also helps to stimulate local economic development by promoting tourism to the area. The People and Parks Programme is an initiative of the National Department of Environmental Affairs and it was established to ensure compliance with the Protected Areas Act. Its objective is to promote the sustainable use of protected areas for the benefit of people.

Oudebosch cabins at Kogelberg Nature Reserve

features

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ABOVE: “In all aspects, the wooden-framed cabins have been designed to minimise environmental impacts in this protected area while maximising the tourism experience,” commented CapeNature CEO Manana Moroka.

LEFT: The cabins are adorned with roof gardens planted with appropriate indigenous species which serve to insulate the structures and allow them to blend with their environment.

BELOW LEFT: Nivenia stokoei (Bush Iris) – one of the many striking fynbos species of the rocky sandstone ridges of the Kogelberg Mountains. It has an underground fire-resistant woody rootstock and brilliant blue flowers which are pollinated by long-tongued flies.

BELOW: The Palmiet River which flows through the reserve near the cabins and is known for its dragonfly diversity.

Courtesy of CapeNature

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This benefit must be attained in a manner which will conserve the ecological character of the protected area and include participation of local people in the management of the areas.

“Public support is essential for the successful implementation of the aims of the biosphere reserve, and every resident and visitor is a potential asset.” Kogelberg Biosphere Reserve by Amida and Mark Johns.

Flora and faunaThe great diversity of plants in the Kogelberg (amongst the highest recorded anywhere) is related to the high variability of terrain, and changing chemical and moisture conditions in the soil. The reserve presents the finest example of mountain fynbos in the Western Cape with a species list of over 1 500 plants of which about 150 are endemic (found only in the Kogelberg area and nowhere else in the world), along with three patches of relict Afro-temperate forest at Louwsbos, Platbos and Oudebos. There are an extraordinary 120 Erica species found in a 240km2 mountain area, amongst the huge range of other plants.

Members of the Protea family include the endangered Marsh Rose (Orothamnus zeyheri) which was once believed to be on the brink of extinction and is now known to occur only on a few almost inaccessible peaks. It was brought back from near-extinction in 1967 by means of a series of controlled burns in the reserve which regenerated the populations and emphasised the importance of fire in fynbos. The Marsh Rose was once favoured as a cut flower – the pink bracts enveloping the flower resemble the petals of a rose – and it is likely that indiscriminate harvesting along with environmental factors were the cause in its near demise.

The area is also home to the highest concen-tration of Mimetes species in the Cape with the endangered M. hottentoticus (Matchstick Pagoda) confined to the southern slopes of just two peaks in the Kogelberg range and the rare M. capitulatus (Conical Pagoda) found only in isolated clumps.

Faunal species at Kogelberg include some leopards, Cape Clawless Otter, smaller antelope

species including Klipsringer and Grysbok – and an abundance of baboons, dassies and hares. Peregrine Falcons, Verreaux’s (Black) Eagles and Fish Eagles hunt and nest in and around the reserve. An endemic freshwater crab and endangered micro frog also occur in the area. The rivers of the inner valley of the biosphere reserve with their pristine riparian vegetation are trout-free and have been declared a ‘hotspot’ of dragonfly diversity.

Sustainable tourism facilityOudebosch comprises five glass fronted, two bed-roomed, self-catering cabins with closed combustion fireplaces, an eco-pool for the accommodation and a small function venue. The stilted cabins are light-weight and adorned with roof gardens and were designed to blend in with the pristine surroundings. Boardwalks weaving through the indigenous landscaping link the individual buildings.

The location of the new facility is a ‘brownfield’ site from which existing cabins were removed and the positioning of services was carefully planned so that they would have a negligible impact on local ecosystems. A comprehensive environmental team including a hydrologist, botanists, ecologists and other scientists, as well as reserve management specialists, worked together to produce a comprehensive Environmental Impact Assessment of the site.

The building materials optimise the balance between low carbon production and durability, so that lifetime greenhouse gas production associated with construction is minimised. Most materials were

sourced locally and virtually all of the materials used could be re-used if the buildings were ever to be decommissioned.

The buildings are framed with local timber and clad with fibre-cement board, Nutec. The use of fibre-cement represents a small fraction of the energy embodied in a conventional brick and mortar structure and also greatly minimises transport emissions.

Gabions or stone baskets have been used for fire protection in a fynbos environment. The latter were also used to construct the eco-pool, as well as to provide durable and attractive bases for some of the structures. The stone baskets represent a high mass but the stone was sourced from local quarries and tones in with the environment.

CapeNature has taken what was considered the most responsible route to reduce carbon emissions from the utilisation of the buildings and this was to use technology that was freely available to eliminate the largest sources of energy use. This was considered a wiser option than to attempt to go entirely off the Eskom grid. CapeNature comments that “…as an organisation we achieve greater overall carbon emissions reduction through the use of these technologies, rather than by going all out to achieve zero emissions at one site”.

All the units at Oudebosch feature the following:- Passive heating and cooling: proper orientation

and size of windows and doors, combined with high levels of insulation and sealing, virtually eliminate the need for active heating and cooling by means of electric heaters and air conditioners.

- High efficiency, clean wood-burning closed

ABOVE: The eco-pool does not make use of any chemicals for disinfecting the water. The water moves through appropriate plants and a filtration substrate in an adjacent lined overflow pool and this serves as a filter.

TOP LEFT: The cabins at Oudebosch are largely constructed of locally sourced timber and stones, and clad with fibre-cement board, Nutec, which represents a small fraction of the energy embodied in a conventional brick and mortar structure and greatly minimises transport emissions.

LEFT: Looking out onto the splendid landscape over the timber trestle dining table in the communal area of a glass-fronted cabin.

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combustion fireplaces: use of alien invasive trees for heating in a properly designed fireplace is a win-win situation. An open plan design means that a comfortable temperature will be maintained throughout the common area.

- Locally manufactured solar geysers for water heating could result in an overall saving of 60-80% of total energy use, compared to a conventional geyser in a guest house situation.

- Gas cookers: direct heat production from Liquefied Petroleum Gas (LPG) allows far more efficient cooking in comparison with electric and even modern induction stoves.

- Highest efficiency refrigerators: in many households, fridges are the appliances that use the most energy. The Kogelberg units contain the most efficient retail fridges available on the South African market and use less than 0,8 kW hours per day.

- Oudebosch features carefully placed light fittings, the use of high-efficiency diffusers (such as frosted glass) and the use of low energy lighting.

With all these features, it is expected that a unit occupied by four people will consume around 2 kW per day (that is around 60 electricity units per month at 100% occupancy). This represents 10% or less of the typical electricity use of a middle-class South African household.

The facility aims to eliminate the use of toxic

chemicals and to minimise water use. South Africa is a water scarce country and responsible water use is a priority, particularly considering that Oudebosch’s water is sourced from the reserve. The design of the water supply system reduces water use from the small and sensitive Oudebosch stream by taking the additional minimal amount required from the larger Palmiet River. The installation of flow control and the use of low-flow showers and faucets has reduced water use to only 3% of the previous facility’s usage. Low-flow shower heads also reduce water heating requirements and associated energy use, allowing solar heating to do nearly all of the work. Reedbeds are used to treat grey water.

The single central eco-pool uses no chemicals, as filtration is done by indigenous wetland plants in an overflow pool in conjunction with a biological filter. Use of toxic pool chemicals and the energy associated with their production is thereby eliminated and the utilisation of a pool pump should be greatly reduced. The water in a properly managed, balanced eco-pool system has none of the detrimental effects of chlorination. The natural pool provides the added benefit of attracting various birds, dragonflies and amphibians.

Composting toilets, while not widely known in South Africa, are internationally recognised as a modern alternative that can greatly reduce water use. These toilets are completely hygienic and odour free. As Oudebosch is not connected to

municipal sewerage lines, the composting toilets are also a key design element that helps to protect the wetlands from degradation, since nutrient outputs are associated with even the best small water-borne sewage treatment plants. This toilet system ensures that nothing is released into the ground and obviates the need to deal with raw sewage by drying waste through a combination of heat and air circulating through the system.

Rehabilitation and roof gardensThe previously occupied bare piece of land was rehabilitated according to strict ecologically sound principles. Locally indigenous species were propagated from plants in the reserve and its surrounds. Plant material, bulbs and seeds were collected from the Kogelberg area during late 2009 and early 2010 and stored or propagated by Sean Privett at the Fynbos Ecoscapes nursery.

The ‘landscape design’ layout was developed by Fynbos Ecoscapes in conjunction with the architects. It includes wetland plantings, the creation of roof gardens, areas of natural bush clumps to provide screening in key places and low, fire resistant, planting close to the buildings. The newly planted areas need a couple of months to establish but should soon reach their full splendour.

The existing lawn surrounding the original cabins was removed. Rock drainage lines were built to collect excess water entering the site, including water from roofs and the natural filter

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beds that were installed to clean grey water from the cabins. These drainage lines were built using local sandstone rocks and form an important structural feature across the site.

Wooden soil-retaining boxes were designed and constructed on the roofs of the cabins.

Coconut fibre and compost were added to the soil mix in these boxes to retain moisture. ‘Soil saver’ material was used to hold the soil in place while the plants establish. The roof gardens were planted with a high proportion of hardy succulent material (that will also produce bright flowers) and a background cover of indigenous grasses. The roof gardens are another architectural feature that serves to gently integrate the cabins with their pristine surroundings. They are also a

natural way of insulating the buildings.The exterior slatted tables and chairs will

be left to weather and fade to grey along with the exposed decks and walkways of the timber cabins. The simplicity of the rustic timber trestle

table in the dining room is complemented by custom-made, locally manufactured chandeliers consisting of recycled beer bottles. The handcrafted scatter cushions in the open plan lounge were made by Learn to Earn, a community based non-profit organisation in Hermanus. Cabin

themes such as ‘Marsh Rose’ and ‘Fire Lilly’ reflect the rare plant species of the surroundings.

Construction World magazine’s Best Projects Awards gave construction company GVK Siya Zama Building Contractors a special mention in the category ‘Specialist Contractors and Suppliers’. The company was also the overall winner at the AfriSam Innovation Awards for Sustainable Construction for their work on Oudebosch.

Article compiled by Carol Knoll from information provided by CapeNature

Photographs by Andree Neser and Courtesy of CapeNature

Email CapeNature for reservations: reservation.alert@capenature.co.za

FAR LEFT: Low-flow shower heads and faucets reduce water use. The shower water drains out through the floor and is filtered by reedbeds.

LEFT: Composting toilets ensure that no nutrients are released into the ground, as the waste is dried by means of a combination of heat and air circulating through the system.

Andree Neser

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