CAT 1: BIODEGADABLE WASTE

OPEN-ENDED BRIEF: There is increasing concern about the impact of putting biodegradable waste into landfill sites, mainly because of the methane it then gives off. Design a way of dealing with biodegradable waste in a way that does not cause pollution and has a useful product.

Either A: Design and make a compost bin suitable for disposing of bio-degradable waste produced in your school.

or B: Design and make a compost bin suitable for disposing of bio-degradable waste produced in the home.

Before you begin:
Key questions for sustainable design and manufacture to ask yourself before you begin

(Note - not all the questions will be appropriate to your particular design idea or product)

• Is the product something that people want and need?
• Will it always be wanted and needed? Is it subject to the whims of fashion? Is it economically feasible to make the product given the whims of fashion and the marketplace?
• Who would benefit the most from this product given their available income and their local environment?
• Will production (and any subsequent repair, recycling) provide work to help people earn money?
• Which raw materials will be used? Are they renewable?
• What pollution is caused by the extraction and processing of the raw materials?
• How will the product be manufactured?
• What other materials are needed in order to use the product? (eg fixings, surface paints or varnishes)
• Can the product be made locally using local skills and local materials?
• How much energy is used at different stages of the products lifecycle?
• How will the product be packaged?
• How will the product be sold / transported to the shops?
• How will the product be promoted / marketed?
• How will it be used? Will it only be used for its intended purpose? How many times will it be used before being thrown away?
• How will it be disposed of after use?
• Could it be repaired? Re-used? Re-cycled?
• Can the product be easily repaired using local materials? How many parts can go wrong? How likely are they to go wrong?
• Materials can be selected to minimise their initial environmental impact.
• The issue of balancing this against the product life can be explored - early replacement simply leads to increased environmental load.
• Structural analysis can be applied to ensure that the size of all components is appropriately minimised
• Styling needs to be explored. There is no point in extending the life of a product in a ‘technical sense’ if it simply becomes redundant in a ‘fashion sense’. For a long product life, a ‘design classic’ is the target.

General background
Households in England and Wales produce 29.3 million tonnes of refuse every year and this is increasing by 3% a year. 82% of this goes into landfill sites (9% is recycled and 8% has energy recovered from it). The organic material in this refuse is 38%. When this organic material goes into a landfill site it decomposes anaerobically and produces methane which is a powerful greenhouse gas (20x worse than CO₂ per unit of gas).
The organic material in refuse consists of food, grass cuttings, other garden waste, paper, cardboard and wood.
These decompose at different rates. Woody wastes decompose very slowly and some plant material quite slowly.

The chemistry of composting
As plants grow, the process of photosynthesis uses CO2 and water to produce plant material and oxygen -
6CO₂ + 6H₂O = C₆H₁₂O₆ + 6O₂

In a compost heap oxygen is absorbed as the organic material is broken down into the carbon dioxide and water that we started with -
C₆H₁₂O₆ + 6O₂ = 6CO₂ + 6H₂O

However, in a landfill site there is no oxygen around for that to happen and methane (CH4) is produced -
C₆H₁₂O₆ = 3CH₄ +3CO₂

Issues to consider
• the type of materials to be composted
• the volume of material to be composted
• the optimal shape and size of the container
• where the container will be located
• the material used for the container itself
• removal of finished material to use on gardens
• avoiding smells
• dealing with rodents

The law and composting in the school
Food contamination in recent years has led to the introduction of regulations intended to minimise the risk of transmission of things such as BSE (ABPO - Animal by-products order). These apply to “catering” waste and therefore to the waste from school kitchens and refectories. The concern appears to be that animals or birds might pick up contaminated material, carry it somewhere else where it could be eaten by something that would carry it into the food chain. There is no evidence that compost heaps have transmitted problems in this way. The only materials that could cause problems are animal products.
The regulations say that “catering” waste can only be composted if it is in a closed vessel and the temperature reaches a high enough level for long enough. The composter has to demonstrate that the temperature levels have been reached.
If the vessel was completely closed the material inside would not get enough oxygen and would therefore produce methane. The smallest animal that would need to be kept out would be a small rodent.
The impact of this regulation is that food waste that was previously composted is now going into landfill sites. At the same time the Government have recently set the following targets -
at least 25% of household waste to be recycled or composted by 2005
at least 30% of household waste to be recycled or composted by 2010
at least 33% of household waste to be recycled or composted by 2015
Also the EC landfill directive (1999/31/EC) aims to phase out the landfilling of biodegradable waste.

Websites & other resources
www.defra.gov.uk/environment/waste/strategy
The government’s current strategy for dealing with waste in England and Wales.

www.wastewatch.org.uk
Wastewatch run Schools Waste Action Clubs (see the “school” section on their website). Their website also has a list of educational resources (including the free pack Wise up to Waste) and information sheets on waste topics (both in the “information” section of their website)

www.wasteonline.org.uk
Work at Waste at School is a Wastewatch practical guide available to download on the Waste on Line website, which is intended to be a one-stop source of information, resources and organisations useful to schools.

www.compost.org.uk
Search for Animal by-products order for details of the regulations.

www.cylch.org.uk
The organisation in Wales co-ordinating work on waste. Centre for Alternative Technology, Machynlleth SY20 9AZ
www.cat.org.uk [email protected]

About Managing Waste
Book with a great deal of useful factual information and separate teachers notes. It contains sections on What is waste?, The history of waste, What happens to waste?, Designing to reduce waste, Conserving resources, Recycling in practice and What about the future? £5.99
Waste and Recycling
One of the Issues series. Contains short, illustrated articles by a number of different organisations, giving a broad perspective. Photocopiable.
£ 6.95 available from CAT

There are a great variety of compost bins on display and in use at CAT, including a number of commercial ones and ones made from waste materials, ranging from car tyres to old freezers. There are also a variety of “recipes” for the contents.

CAT 2: MOVING WATER

OPEN-ENDED BRIEF - Moving water from one place to another, particularly lifting it, has been an engineering challenge for millenia and very many different methods have been used to do this over the centuries. Design and make a system for moving water for a situation of your choice.

SPECIFIC BRIEF - There is an ever-growing interest in gardening and many people are building ponds in which they want to have some sort of moving water feature. There are issues of energy and water consumption involved. Design and make a system which will provide moving water in a low impact and low cost way.

Before you begin:
Key questions for sustainable design and manufacture to ask yourself before you begin

(Note - not all the questions will be appropriate to your particular design idea or product)

• Is the product something that people want and need?
• Will it always be wanted and needed? Is it subject to the whims of fashion? Is it economically feasible to make the product given the whims of fashion and the marketplace?
• Who would benefit the most from this product given their available income and their local environment?
• Will production (and any subsequent repair, recycling) provide work to help people earn money?

• Which raw materials will be used? Are they renewable?
• What pollution is caused by the extraction and processing of the raw materials?
• How will the product be manufactured?
• What other materials are needed in order to use the product? (eg fixings, surface paints or varnishes)
• Can the product be made locally using local skills and local materials?
• How much energy is used at different stages of the products lifecycle?
• How will the product be packaged?
• How will the product be sold / transported to the shops?
• How will the product be promoted / marketed?

• How will it be used? Will it only be used for its intended purpose? How many times will it be used before being thrown away?
• How will it be disposed of after use?
• Could it be repaired? Re-used? Re-cycled?
• Can the product be easily repaired using local materials? How many parts can go wrong? How likely are they to go wrong?
• Materials can be selected to minimise their initial environmental impact.
• The issue of balancing this against the product life can be explored - early replacement simply leads to increased environmental load.
• Structural analysis can be applied to ensure that the size of all components is appropriately minimised
• Styling needs to be explored. There is no point in extending the life of a product in a ‘technical sense’ if it simply becomes redundant in a ‘fashion sense’. For a long product life, a ‘design classic’ is the target.

Issues -
What do people want from a water feature?
• In a large deep pond there is sometimes a need to aerate it, to get oxygen into the water or to agitate the water to deal with pollution. In a small garden pond that is not usually a problem, except perhaps in the winter.
• For some it is aesthetic. They like the look or sound of moving water.
What form of effect would be appropriate - fountain, flow, waterfall, other?
How much water needs to be moved and when - all the time, randomly, on demand when people want to see or hear it?
What are the options for an energy source -
manual,
electricity from the mains,
windpower directly moving a mechanism
windpower generating electricity to run a pump
solar power generating electricity to run a pump
water power
Consider what each source needs to work (e.g. not a very sheltered spot for windpower)
Where is the water going to come from (mains, rain, the pond itself?)

Resources
Books
3 books on the history of pumping and wind and water power -
Wells and pumps - John Vince, Sorbus - describes how the water pump evolved (£2.95)*
Windmills and how they work (John Vince) (£2.95)*
Wind and Water Power - Martin Watts (£7.99)*
Energy post 16 (TEP) - Designing a solarimeter, anemometer and wind turbine, written for A-level*
Pupil’s Guide to Windpower - CAT (£3)*
Pupil’s Guide to Solar Power - CAT (£3)*
Teacher’s Guide to Solar Electricity Projects - CAT (£4)*
An introduction to Photovoltaic Power Factsheet - CAT (£3)*
CAT Tipsheets -
Solar Fountain (50p)*
Hydraulic Ram (50p)*
CAT Resource Guides (lists of organisations, equipment suppliers and publications) -
Water Supply, Treatment & Sanitation (£3)*
Components of Renewable Energy Electricity Systems (£2)*
Wind Power (£3)*
Solar Electricity (£3)*
Photovoltaics in the UK: An introductory guide for new consumers - Environmental Change Institute, University of Oxford (£6)*
Water Pumping Devices - Peter Fraenkel, ITDG (£19.95)
Windpumps: a Guide for Development Workers - Barlow et al, ITDG (£14.95)
A Manual on the Hydraulic Ram for Pumping Water - Simon Watt ITDG (£7.95)
Six Simple Pumps - VITA*
Building a Domestic Windpump - Jim Barr (£5.99)
* available from CAT mail order www.cat.org.uk 01654 705959
www.bwea.com The British Wind Energy Association
www.itdgpublishing.org.uk
www.cat.org.uk
www.windpumps.co.uk
www.itpower.co.uk
www.marlec.co.uk
www.vergnet.fr
www.intersolar.com
www.bp.com/bpsolar
www.oceanarks.org

Examples of manual, wind and solar pumps and a hydraulic ram can be seen in use at the Centre for Alternative Technology, Machynlleth, Powys SY20 9AZ
www.cat.org.uk

CAT 3: FOOD AND SUSTAINABILITY

OPEN-ENDED BRIEF - The food we eat has a huge effect on the environment. In the UK it represents about a third of our total impact on the planet, as measured by the ecological footprint. Much of that impact is caused by the processing, packaging and transporting of the food.
Design one or more food items which will have a low impact on the planet, or a positive impact of some sort.

SPECIFIC BRIEF - School dinners often include a lot of processed and ‘quick’ foods, because of the pressures of cost, convenience and producing things that pupils will eat. Design a meal or menu for school dinners that is low impact, interesting and healthy.

Issues to consider
Food footprints
Food in season
Fair traded ingredients
Organic growing
Food and health

Sources of information

Food for All- John Madeley
The Hunger Business - John Madeley
Sharing Nature’s Interest, ecological footprints as an indicator of sustainability - Chambers, Simmons and Wathernagel ( £13.95)

Issues books - titles include -
Food for thought
Vegetarianism
The ethics of Genetic engineering
Forestry and Farming Litvinov, Heinemann. £5.99,

www.bigbarn.co.uk
Big Barn is an organisation which gives information about sources of local food and lists what is in season
www.hdra.org.uk The organic association - info for the general public and the Schools Organic Network
www.soilassociation.org info on organic growing, including healthy school meals
www.sciam.com article in the January 2003 edition of Scientific American - “Rebuilding the Food Pyramid” on the latest version of the pyramid of a healthy diet.
www.newint.org New Internationalist magazine (the magazine may be in your school library) and website (search the back copies for food issues). -
www.yorkfootprint.org For footprint data on food - Technical Report of the Eco footprint of York (also Sharing Nature’s interest)
For information Fair Trade -
www.fairtrade.org.uk
www.bananalink.org.uk
www.divinechocolate.com

www.foodandfarming.org.uk
www.grab5.com this is the alliance for better food and farming’s project to encourage kids to eat more fruit and vegetables
www.sustainweb.org

www.wiredforhealth.gov.uk
The Healthy Schools Programme is part of the UK Governments’s drive to improve standards of health and tackle health inequalities. Its aim is to make children, teachers, parents and communities more aware of the opportunities that exist in schools for improving health. There is a newsletter and, a young people’s network.

CAT 4: SOLAR WATER HEATING

OPEN-ENDED BRIEF -
The potential for using solar water heating systems in Britain is enormous, with 40,000+ already in use in homes. Design and make a solar water heating system for a context of your choice.

SPECIFIC BRIEF
Either A: Design and make or model a solar water heating system suitable for use in a home similar to your own.

or B: Design and make or model a solar water heating system for use when camping.

Before you begin:
Key questions for sustainable design and manufacture to ask yourself before you begin
(Note - not all the questions will be appropriate to your particular design idea or product)

• Is the product something that people want and need?
• Will it always be wanted and needed? Is it economically feasible to make the product?
• Who would benefit the most from this product given their available income and their local environment?
• Will production (and any subsequent repair, recycling) provide work to help people earn money?
• Which raw materials will be used? Are they renewable?
• What pollution is caused by the extraction and processing of the raw materials?
• How will the product be manufactured?
• What other materials are needed in order to use the product? (eg fixings, surface paints or varnishes)
• Can the product be made locally using local skills and local materials?
• How much energy is used at different stages of the products lifecycle?
• How will the product be packaged?
• How will the product be sold / transported to the shops?
• How will the product be promoted / marketed?
• How will it be used? Will it only be used for its intended purpose? How many times will it be used before being thrown away?
• How will it be disposed of after use?
• Could it be repaired? Re-used? Re-cycled?
• Can the product be easily repaired using local materials? How many parts can go wrong? How likely are they to go wrong?
• Materials can be selected to minimise their initial environmental impact.
• The issue of balancing this against the product life can be explored - early replacement simply leads to increased environmental load.
• Structural analysis can be applied to ensure that the size of all components is appropriately minimised
• Styling needs to be explored. There is no point in extending the life of a product in a ‘technical sense’ if it simply becomes redundant in a ‘fashion sense’. For a long product life, a ‘design classic’ is the target.

Sustainability issues
• The energy source used to heat most hot water used in Britain is a fossil fuel. Burning fossil fuels adds to Climate Change and air pollution. The Royal Commission on Environmental Pollution has stated that “The government should now adopt a strategy which puts the UK on a path to reducing carbon dioxide emissions by some 60% from current levels by about 2050”.
• Heating water accounts for about 22% of energy used in homes in Britain (not including central heating).
• On average commercial solar water heating systems produce about 50% of the hot water needs of a home over the course of a year.

Other issues
• How much hot water is needed?
• What temperature does it need to be?
• When is it needed?

Sources of Information
Energy post 16 (TEP) - Designing a solarimeter and solar water heating system, written for A-level*
Pupil’s Guide to Solar Power - CAT (£3)*
Solar Water Heating, a Resource Guide - CAT (£2) Comprehensive list of organisations, suppliers and manufacturers.
Tapping the Sun - a guide to solar water heating - CAT (£3.50)
Solar Water Heating: a DIY guide - CAT (£5.99)
Solar Energy Factsheet - CAT (£3)
The Practical Solar Handbook - Bushell (£6.95)
Solar Water Heater - VITA (£8.95) guide for the construction of a portable solar collector and storage tank.

www.solartradeassociation.org.uk The solar Trade Association aims to maintain standards within the industry and to promote the use of solar power.

www.ecoconstruct.com Construction Resources is a builders merchants specialising in ecological materials, including solar waters panels. 16 Great Guildford St, London SE1 0HS

Examples of a variety of solar water heating systems can be seen in use at the Centre for Alternative Technology, Machynlleth, Powys SY20 9AZ
www.cat.org.uk

Manufacturers of panels and solar products
www.filsol.co.uk.
www.solartwin.com
www.solardesign.co.uk
www.thermomax.com
www.aessolar.co.uk
www.solarmatt.com
www.specialmetals.com Manufacture an ultra thin black oxide nickel foil for high absorption and low emittance of infra red radiation.

Clip fins for solar collectors are available from CAT mail order.

CAT 5: USING TIMBER SUSTAINABLY

OPEN-ENDED BRIEF - When chosen and used with care, timber can be a very low impact material to use for furniture. Design and make a piece of furniture which uses timber in a sustainable way.

SPECIFIC BRIEF - Design and make a piece of furniture using locally grown timber from a source where replanting has happened or where a tree was not cut down.

Before you begin:
Key questions for sustainable design and manufacture to ask yourself before you begin
(Note - not all the questions will be appropriate to your particular design idea or product)

Issues
• The extraction of tropical hardwoods is frequently extremely damaging to the environment. To fell one mahogany tree loggers fell a considerable area of other timber which is left to rot. Deforestation is adding to problems of Climate Change as forested areas are ‘carbon sinks’, which have absorbed carbon dioxide. In many cases when trees are felled they are not replaced.
• Importing timber produces carbon dioxide through the energy used in transport.
• Composite boards make use of small sections of timber but often contain damaging substances in their adhesives.
• When trees are felled and replaced by young trees the carbon cycle can continue.
• Using a certain amount of timber creates a market for it and therefore a value in maintaining woodland.
• A monoculture of conifer trees can be very damaging to the local environment. Planting mixed forestry of indigenous species creates habitats for wildlife and very pleasant woodland for leisure pursuits.

Sources of information
www.coedcymru.mid-wales.net
www.forestsforever.org.uk
www.trada.co.uk The Timber Research and Development Association
www.fscoax.org The Forest Stewardship Council
www.greenwoodtrust.org.uk
www.foe.org.uk friends of the Earth have produced The Good Wood Guide and Stop the Chop - new guide to buying wood without wrecking forests
The Whole House Book - CAT, info on timber and other materials

CAT 6: ECOLOGICAL HOUSING

Ecological Housing

A few committed designers and builders are gradually extending knowledge and practice in energy efficient, ecological methods of construction. Design and make a model of an energy efficient, pre-fabricated house or alternative building, or a component for such a house. It should use ecological materials and renewable energy systems, as affordable, and be appropriate for use in the UK.

INTRODUCTION

Alongside increasing concern in this country that we need to be minimising our use and wastage of resources, and moving towards more sustainable building generally, there is a huge demand for new housing to be built throughout the country. The government has projected a need for 4 million new homes in the next 20 years. This is partly due to demographic fluctuations in the size of family units. There are of course environmental arguments that we could be making better use of existing building stock, with eco-renovation and conversion projects.  However, we will look at new build here for simplicity.

‘About half of the total national energy bill goes into servicing buildings…Of this figure, about 60% is used by domestic buildings, or 29% of the total.’

From The Whole House Book.

The ecological building market and industry in this country is currently small and limited in its skill base.  It relies on a few committed designers and builders to experiment and increase knowledge about energy efficient, ecological methods of construction.  These businesses tend to be small, poorly financed, generally involved in one-off designs.

If sustainable construction is to become more widespread, these skills obviously need to become more mainstream.  One  suggestion to promote this is that small regional factory units could produce pre-fabricated house units. In this way, the skilled design and construction methods would reach a wider market.  There would be more interest from developers and mass house builders, since they would be more able to commercially afford the mass produced units. On site construction time would be reduced, and the level of detailing required to produce energy efficient housing would be partly carried out under factory conditions, minimising reliance on hard-to-monitor site workmanship.

This is in line with current trends in the building industry, in the UK and mainland Europe.

The environmental costs of the transport to bring the components to site would be offset by reducing the daily transport costs of tradespeople to site, since the on-site construction period would be much reduced.

GENERAL CRITERIA

The house design should take into account the ecological criteria outlined in the General Reference Section.

POSSIBLE DETAILED STUDY SUBJECTS

1. CONTEXTUAL STUDY

For such pre-fabricated housing to have any chance of success with the UK public as permanent desirable housing, it needs to be long-lasting, substantial in its materials, attractive, and possibly fit in to a regional character. This is alongside all of the benefits to comfort and health, and the sunny attractive interiors that the above sustainable design criteria will bring.  To facilitate these qualities, a study might include looking at the following;

• Look at past or current examples; for example, 1,000’s of pre-fab. houses were put up after World War 2, and some still remain standing, albeit renovated. There are also examples of these in some of the open air museums, i.e. Avoncroft and Chilterns Open Air Museum.  Recent well-known examples of pre-fabricated houses include the ‘Castaway pods’ for the t.v. programme of the same name.
• How are the houses built in your area? Commonly, the ‘brick’ houses filling new estates all round our towns are theoretically timber framed houses, with the brickwork solely providing a substantial rainscreen, and that desired impression of masonry construction.  A lot of these new houses may include pre-fabricated wall and roof panels and trusses.
• Choose an area of the country for the design; a hebridean island or an infill site in Birmingham would bring contrasting ideas to inform the design
• Study weather patterns of the area; rain, sun and wind. The nature of the exposure of the site will inform the type of materials chosen
• Create a profile of a typical user; this could vary enormously from an independent self-builder working co-operatively with a small group to build a small estate of detached dwellings, or a developer building a terrace of houses
• Study regional typical build costs,
• Look at materials of the region (vernacular); how can the new houses fit in with these. Can the design be adapted to have a steep clay tile roof in Northumberland, and a parapet design in regency Cheltenham, for example.
• Are different cladding of the walls possible to encourage this variation

2. STRUCTURAL / CONSTRUCTION STUDY

• Study the different types of construction used to build houses in the UK; post and beam, stud framing, masonry – solid or cavity wall.
• Which systems are most appropriate for pre-fabrication
• What type of materials can maximise the pre-fabrication process; i.e. is a frame made in the factory and clad on site, or are wall and roof panels prepared and insulated in the factory etc.
• How do these processes work on site; what equipment is needed for construction; how are panels or components joined together ?
• How is airtightness of the construction, etc. ensured ?
• Once a building is super-insulated, it is vital that ventilation for fresh air internally is through controlled openings, i.e. windows and trickle vents in windows, and mechanical ventilation. Great care has to be taken in the construction to avoid uncontrolled air leakage between elements of the construction, e.g. between window frame and structure.

3. MATERIALS STUDY

• Look at health of materials
• Look at the sources of current conventional building materials, and compare their embodied energy with that of more ecological materials. Generally speaking, materials have less embodied energy if they are natural, unprocessed, involve simple fixing on site, and minimise transport.
• This may involve looking at new technologies to produce insulation and board materials from plant and organic fibres and wood; flax, straw, hemp, sheepswool, wood fibres etc.
• Recycled materials may also lead to knowledge of existing techniques or of new possibilities; re-use of car tyres, glass, crushed concrete etc.

4. TECHNOLOGY STUDY

• Look at solar hot water heating, wind turbine technology, photovoltaics, water saving technology, biomass district heating etc.
• Compare the types of technology used in current example projects around the country; ‘Castaway pods’, Taransay, Scotland; ‘House for the Future’ at Welsh Museum of Rural Life, St.Fagan’s,Cardiff; Integer House, BRE site, Garston,Watford; various houses at the Centre for Alternative Technology, Machynlleth, Powys.; Eco-House, Leicester Ecology Trust,Leicester etc.
• Survey current technologies and decide what may be appropriate (i.e. user-friendly and easily maintained) and affordable for householders.
• Focus in on one element of your designed system, and design and make a particular component.

SUGGESTED WORK PRODUCED

• Plans, sections and elevations, and 3-D drawings of the house, 1.50 metric scale or larger
• Model of the whole or parts of the construction, 1.50 or larger; this could be a roof truss that could be easily tested by weighing down with water; or a section of wall construction showing the layers of rainscreen, sheathing boards, insulation materials, structural components, and internal lining materials
• Full scale model of a particular component, using the actual materials of construction.
• Separate reports in the different study subjects, showing how this research information has informed the design and make project chosen.