Why is it important?
Shelter is important for providing safety from natural and human threat, for offering privacy and for creating a sense of ownership and belonging for its occupants. Sound shelter design incorporating environmental considerations is concerned with materials, location, and design for use. Shelter has a significant impact on the environment particularly through the use of natural resources but also in transportation of materials (embodied energy).
- Do you understand the environmental issues (have you carried out a rapid environmental assessment) and that you know of local environmental sensitivities?
- Can you show that the design incorporates traditional and local building knowledge?
- Will you use local materials and local labour?
- Can you show an awareness of the environmental impact of your choices of construction materials e.g. embodied energy.?
Inappropriately designed shelters will reduce the standard of living of people served by humanitarian organisations. This directly contradicts the humanitarian imperative to reduce suffering.
Resource Depletion & Greenhouse gas emissions
Shelter location and design can impact the extent that passive heating or cooling takes place. Insufficient heating or cooling can lead to an increase in energy consumption as fuelwood or charcoal is used for heating and electricity for refrigeration or the use of fans. Increased energy use can lead to excessive fuelwood harvesting which leads to deforestation, loss of habitat, soil erosion, emission of greenhouse gases and impacts respiratory health. Use of electricity from fossil fuel sources via generators also contributes to the carbon footprint of the site (see Energy section for more information).
If the site selected does not provide sufficient ventilation, this can lead to reduced indoor air quality as fumes from indoor cooking are not being extracted effectively and can lead to increased internal temperatures.
More Resource Depletion
Energy efficiency is the goal of minimising the amount of energy needed to to do a specific task. If using a fossil fuel derived fuel source this directly reduces the amount of greenhouse gases released to the atmosphere. Whereas if using energy derived from renewable sources this reduces the load on the energy producing system. A classic example is that of using insulation to reduce the amount of energy needed to heat a building.
Increasing energy efficiency reduces demands on local energy supplies such as forestry (mitigating deforestation) or imported fuel sources. Energy is often derived from fossil fuels, using large amounts of energy increases greenhouse gase emissions.
More Greenhouse info
Greenhouse Gas Emissions
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect which maintains the stable temperature of the Earth.
Since the Industrial Revolution there has been a 40% increase in greenhouse gases in the atmosphere which is believed to be contributing to a change in the Earth’s climatic systems. Changes in this system is increasing the vulnerability of many populations.
The selected site also needs to provide effective draining. Its absence can lead to increased water logging which deprives the soil of oxygen and prevents its use for agricultural purposes.
Shelter construction and waste disposal can damage sensitive local environments (see Construction). Settlements can be in use for several years and as they become upgraded, and shelter potentially more permanent, significant amount of waste can be created from shelter deconstruction which can lead to pollution if not disposed of appropriately.
More Environmental Degradation Info
A break down synopsis of the entire degradation section would be useful here.
Environmental impact assessment can be undertaken to determine and hence reduce damage to local environment by settlement construction.
Utilising local knowledge
Assessment of local building traditions should be conducted, and cooperation with local organisations and involving of community to understand how a site can provide the most effective adaptation to the local climate.
Furthermore, designing and building structures which are locally appropriate will normally lead to cost savings through local material choices and will provide employment for local artisans. Both of which can have a favourable impact on local economies.
Choosing appropriate materials
Ultimately, materials should be sourced sustainably, as much as possible recyclable or reusable, and enabling shelter upgrade with minimal waste.
This, however, is not always possible in humanitarian situations. But designing with environmentally appropriate materials in mind is. Factors to bear in mind when choosing materials are:
- Embodied energy – how much energy is required to produce and transport the material?
- Transport distances – can the material be sourced closer to site?
- Resource depletion – is the material being sourced sustainably, for instance is timber procurement causing deforestation, is soil or aggregate procurement increasing the risk of landslides or having an impact on water management?
- Will the population accept unusual materials – for instance, the affected population may not want to live in compressed earth buildings, no matter how environmentally friendly and will look to construction from brick or concrete in the future.
An entire lifecycle analysis of materials would be helpful but not always possible. Considering material choice using a ‘systems approach’ where all of the inputs (energy, water, raw material, etc) and all of the outputs (GHGs, non-recyclable waste, water pollution, etc) will be of assistance.
For more information see the ‘Material Information’ sheet here.
For hot climates
For hot climates, agencies should aim to minimise solar heat gain and maximises passive cooling measures such as:
- steep roof angles (minimises solar heat gain)
- building form (low surface to volume ratio for hot dry climates)
- Considering solar orientation over the year
- building form that maximises air flow
- allow cross ventilation (such as horizontal openings in walls)
- use wind catchers
- Landscaping: Vegetation and running water can cool the airflow;
- Insulated roofs to minimise heat gains BUT no insulation in the walls if the building is not air-conditioned
- wall surfaces with high thermal resistance
- shading and glazing considerations such as external shading devices (overhangs etc.)
For cold climates
For cold climates, shelter design should minimise heat energy losses through measures such as:
- Using existing buildings or geography, building orientation and site layout to protect from cold winds
- Considering use of rooms and arranging heated rooms close to each other;
- If livestock is kept, consider proximity of barns etc. to make use of body heat;
- Maximisation of solar heat gains through orientation;
- Ensuring compact building forms;
- Insulating well (consider environmental/health impact of insulation materials);
- Minimising windows opposite of the equator; and
- Keeping ventilation rates low to minimise heat loss. However, consider necessary ventilation to avoid health problems from indoor air pollution and excessive moisture.
Regarding ventilation, for:
- Hot and humid climates: choose maximum constant ventilation at high air velocities to maximise sweat evaporation
- Hot and dry climates: choose constant airflow at lower velocities
- Cold climates: choose minimum airflow to avoid heat loss. Buildings should be ventilated strongly in a short time.
WWF and American Red Cross – Green Recovery and Reconstruction Toolkit Module 5 – Green Guide to Materials and the Supply Chain.
Practical Action – manufacturing and process industries.
SKAT – building material leaflets, 2006.
URD and UNEP – training about environment throughout the project cycle.
The FSC has produced timber certification here.
The FAO has produce guidelines for forestry management.
The British Geological Survey has information on the environmental impact of quarrying here.
The Natural Resource Institute has information on the environmental impact of small scale mining here.
The UNEP have collated information about land and forest management here.
UNHABITAT – Building Materials and Health.
The International Standards Organisation has produced ISO 14000 international standards for environmental management.
The Pro Act Network and Shelter Centre have produced a brief guide to construction waste.