Greenhouse/ Blackhouse is an exhibition that looks at sustainable development in relation to architecture and sense of place.
In many ways vernacular responses to the design of dwellings such as the Highland Black House were the ultimate in sustainable living, as of necessity they were built of local materials and used renewable energy sources for heat and light. However, despite being ‘at one with nature’, lack of choice also meant that they did not create an ideal internal environment. Until the recent acceptance of the negative impact that profligate use of the planet’s natural resources is having on the Earth, access to choice in the 20th Century resulted in an ‘international style’ that crossed many boundaries and arguably divorced people from the important role that local climatic and ecological issues played in shaping the built environment of the past. Greenhouse/ Blackhouse explores how a 21st century reappraisal of our connection with the planet could give us the best of both worlds: a new, sustainable vernacular, using resources sensibly that is a pleasure to live in?
Greenhouse/ Blackhouse introduces the current state-of the-art in sustainable housing design in Scotland and Europe. The aim is to provide inspiration by exploring new and innovative solutions alongside traditional methods – from selecting appropriate locations to build, through harnessing the climate and responsible resource use to issues of lifestyle and health. The exhibition’s centrepiece is a presentation of the entries to the Highland Housing Fair competition, which aims to create a new eco-community in the Highlands.
This exhibition formed part of the Six Cities Design Festival in Inverness in May 2007. It explored state-of-the-art sustainable housing design in Scotland and Europe alongside entries to the Highland Housing Fair Design Competition. Videos exploring issues surrounding sustainable housing were shown in the exhibition.
The exhibition explores the various issues that need to be considered when designing sustainable housing. These include:
Where do you want to live?
Location – the needs of people living in urban, rural or suburban environments are different. Buildings in cities, towns, suburbs or the country all look different from one place to another.
What kind of site is best? – we can reduce damage to the environment by building on a site that has been built on before – ‘Brownfield’ – rather than a previously undeveloped – ‘Greenfield’ – site. However, building on any site will have an impact on the existing and future ecology of that site.
Transport – there is always a need to travel to-and-from the place where you live. In some cases the mode of transport used allows a free choice, but in others the options are limited, e.g. some journeys are appropriate to make on foot, by cycle or by public transport (if available), others may not be.
Form and Orientation – make the most of the natural features of the site. It is important to consider certain aspects of the house design to help reduce energy use. The layout of the house can have a significant impact, a house with a compact plan will lose less heat than a sprawling plan with the same area. Controlled ventilation and draughts can be uncomfortable and can also lead to unnecessary heat losses, these can be reduced by adding porches or sunspaces to external doors. Plan your house so that all rooms can be naturally lit. You should be able to see the sky from all the main rooms. Building over more than one floor reduces the environmental ‘footprint’ of a building. Similarly, it is possible to make the most of the land around a house for complimentary activities to make the development more self-sustaining. A house should be easily adaptable to meet changing need and expectations. Enhance the surrounding area for neighbouring residents and take care designing the spaces in between buildings.
Energy and the Environment
Energy use and houses – all houses require energy in some form or another. Although the concept of Zero Energy Houses is appealing, it is not possible to produce houses without using energy in construction. The energy required to operate dwellings has to be provided either directly, by burning fuel, or by using other natural resources such as water or wind power, or indirectly in the form of electricity purchased from a supplier.
Energy use and climate change – burning any fuel material releases carbon dioxide (CO2) and water vapour into the environment, both of which are greenhouse gases – especially CO2, which are believed to contribute to global warming and other climate change effects, and which are depleting natural resources. Different fuels also release varying quantities of other compounds into the atmosphere, many of which are in themselves toxic. When choosing between types of fuel it is also important to consider depletion of the world’s resources, protection of threatened environments and the overall balance of carbon in the atmosphere.
Fossil Fuels – gas, oil and coal are called fossil fuels. They are the remains of living organisms that have been trapped in the earth for thousands of years and contain high levels of carbon. Peat is similar in this respect. Organic materials form part of a cycle in which carbon is released into the atmosphere from decaying or burnt organic matter, on land or in the oceans, and recaptured from the atmosphere by plant life across the planet. The burning of fossil fuels puts the balance of this ecosystem in jeopardy by introducing carbon dioxide into the atmosphere faster than it can be absorbed by plants.
Renewables – renewable energy is a broad term covering all sources of energy, which do not involve burning fossil fuel or the use of nuclear power. There has been a lot of pressure to classify waste as a renewable, however any batch of waste will only be as ‘renewable’ as the individual items of waste it is made up of – think of the contents of your dustbin! Renewables include: biomass (it is important to consider the source of biomass and a ‘clean burn’ to ensure less toxic by-products), solar (solar photovoltaic cells or solar thermal panels), wind and water power, ground source heat pumps, hydro-electric power.
Energy saving – a way of reducing energy demand is by using insulating materials in the home, ground floors, external walls and roofs can be insulated with a variety of materials. With this insulation it may only be necessary to heat the house for a few months of the year. Other ways to reduce energy is to make the most of natural lighting, use low energy light fittings, Eco-labelled electrical fittings and install responsive and easy to use heating.
Pollution and toxic substances – many of the processes used to make building materials involve processes that pollute the environment, e.g. the manufacture of PVC for the frames in windows and doors. Other building materials are poisonous or hazardous, such as lead or asbestos. Some materials will also become more problematic when the building is finally demolished – e.g. asbestos and preservative-treated timber.
Energy and manufacturing – the processes used to manufacture some materials use very high levels of energy and produce large amounts of CO2, e.g. almost a tonne of CO2 is produced in the manufacture of 1 tonne of Portland cement. There is an argument for using materials that are made using less energy.
Energy and transport – construction site deliveries also contribute to greenhouse gas emissions – the further each material or product has to travel, the more energy is used in transporting it. The ‘embodied energy’ in a material can therefore be reduced by specifying locally produced materials and products where possible.
Local products – there can be many advantages in sourcing good quality building materials locally. Using local materials reduces transport costs and saves on the energy that would have been used to import the materials from further away.
Recycling and re-use – many building materials can be re-used and there is a market for good quality second hand building materials. Often these are more sought-after than the nearest new alternatives. Second hand Scottish slate or old hand-made bricks for example are very desirable.
Design for deconstruction – buildings can also be constructed so as to facilitate future dismantling and demolition. Building materials can be chosen which can be re-used or recycled in the future.
Home working – home computers widen the possibilities for home-based working. To allow this, a house requires space for a home office or workshop.
Self sufficiency – any food grown on site will also reduce your ‘food miles’ – that is the distance that you have to travel to where you purchase your food.
Consuming less – before throwing away and replacing old equipment and furniture we should ask – can it be repaired or modified? This will reduce the use of the earth’s resources and energy needed to manufacture and transport goods.
Sharing skills and assets – look at possibilities for car pooling or car rotas with neighbours or work colleagues.
Permaculture principles – create a more productive landscape ¬¬– use the land around your house for complementary activities to make the development more self sustaining, e.g. allotments, woodland, wildlife areas or renewable energy generation.
Ecological footprint – how much of the planet’s resources do you need to maintain your lifestyle?
Toxic substances in buildings – small traces of toxic substances can cause serious health problems over a long period of time. Since we spend more of our time at home than in any other building, we must take seriously the health implications of the materials used in house-building.
Heating – all combustion appliances must be properly ventilated. This usually means a chimney or flue, as if there is not enough oxygen then the fire or boiler will give off poisonous carbon monoxide gas.
Insulation – insulation has to be properly installed to work effectively. Poor or inadequate insulation in walls or ceilings will also create cold spots where condensation forms, and this can create an environment for mould to develop.
Ventilation – a well insulated, draught-free house still needs fresh air for people to live healthily. Some forms of ‘breathable’ construction allow air to permeate slowly through all the component parts of the wall or roof.
Durability and maintenance – buildings should be designed and built for a long useful life and to keep maintenance requirements to a minimum.
Life cycle costings – different parts of the building, and different components, will need repaired or replaced at different times during the life of the building. It is a good idea to plan ahead for what is most likely to be required and when, and how much future maintenance work is likely to cost. This is what is meant by ‘life cycle costing’.
Access for maintenance – the parts of the building that will need cleaning and maintenance more frequently include windows, roofs, gutters, paintwork, drainage and service installations and any mechanical apparatus. Gas boilers for example require a yearly inspection. These parts of the building should be easily and safely accessible.