QUAKER GREEN ACTION
The Witness of Our Buildings
Information sheets to help Friends make our
buildings less damaging to the environment
I. ENERGY CONSERVATION
As explained in information sheet II. Sources of Energy for Heating etc our consumption of fossil fuels is leading to serious damage to the earth. For most buildings, heating is the largest consumer of fuels and it is only in very modern, well-insulated buildings that the consumption for hot water, lights and electrical appliances may be larger. The primary focus of this sheet is thus heating.
The amount of pollution we generate from heating with fossil fuels depends on three factors:
- The fuel we choose
- The efficiency of the boiler and heating system
- The ability of the building to retain heat
This sheet addresses the second and third of these, for the first factor see information sheet II.
The efficiency of the boiler and heating system
For older buildings the most critical component in the heating system, in terms of the effect on the consumption off fossil fuels and the resultant carbon dioxide pollution, will be the boiler efficiency and the controls fitted.
We are lucky that now the Government has created a freely accessible internet listing at containing the tested efficiency of all boilers in the UK, both new and old.
This allows comparison of the performance of different boilers on an equal basis. Before these standards were agreed, manufacturers would often quote the peak rather than seasonal average efficiency for their products, and worst still, use different bases for the calculation, making effective comparison very difficult.
All boilers that are listed have a SEDBUK rating (short for “seasonal efficiency of domestic boilers in the UK”). This figure is representative of the likely efficiency to be found in practice with UK heating systems and weather variations. The figure ranges from around 55% to 92% for the most efficient boilers (see table below). For convenience, all boilers are divided into seven bands, A to G, in a very similar way to the labelling of fridges, freezers and washing machines.
Energy Conservation (April 2002))Page 1
SEDBUK rating / EFFICIENCYA / 90% and above
B / 86% - 90%
C / 82% - 86%
D / 78% - 82%
E / 74% - 78%
F / 70% - 74%
G / Below 70%
The new building regulations that came into force in April 2002 mean that effectively boilers in categories E, F and G are no longer allowed to be installed in the UK, and it is expected that manufacturers will stop making these boilers. However, that still does leave a tremendous range from the bottom of band D (78%) to the top of band A (92%).
Energy Conservation (April 2002))Page 1
It is recommended that all boiler replacements are taken from band A only. This will be a modest extra cost for homes and meeting houses (say £400), but will produce savings in fuel use and hence pollution and cost, of around 15%, before considering any extra savings from controls.
There are three rules for heating system controls:
- There should be a room thermostat and a time switch for the heating, and similarly a cylinder thermostat and time switch (or programmer) if the system also supplies hot water from a cylinder.
- The controls should have “boiler interlock” i.e. the boiler should not fire unless there is a call for heat. This sounds just good practice, but it is estimated that there are around 25% of central heating systems in the UK that do not have this feature
- The systems should be fully pumped, that is gravity circulation should be replaced as it is inefficient.
The savings that are typical from upgrading controls to these standards are of the order of another 15%.
If hot water is supplied by the central heating boiler there are several points to consider.
Hot water cylinders should be insulated and hot water pipes should be lagged. Putting an insulating cover on an uninsulated cylinder will save money.
If the cylinder is to be replaced make sure that it is replaced with a cylinder marked to BS1566. This guarantees that the insulation is of a reasonable thickness and that the heat exchanger will work efficiently with modern boilers.
You may be able to save energy by installing a combination (“combi”) boiler, which heats water as it is used rather than heating a storage cylinder.
There are more general points on water heating below.
The ability of the building to retain heat
This is the second part of the work to be done.
Meeting Houses and other buildings vary a great deal in age, construction, size and location, so that it is difficult to provide information suitable for all. However, the following may contain useful tips.
Energy Efficiency Advice Centres
There are nearly 50 Energy Efficiency Advice Centres in the UK which give free and impartial advice to householders and small businesses on cost-effective ways of saving energy (apparently a Meeting House would count as a small business). All the Centres can be contacted on Freefone 0800-512012. You will be put in touch with your nearest Centre who will send you a simple Energy Survey Form for Small Businesses.
For most Meeting Houses this may be more appropriate than paying for an energy rating. However if you are considering buying a new property for use as a Meeting House it might be worth paying for an energy rating assessment before deciding on the purchase.
Energy Rating
There are two national home energy rating schemes - higher numbers indicate greater energy efficiency:
The Standard Assessment Procedure (SAP) on a scale from 1-120
The National Home Energy Rating (NHER) on a scale of 0 to 10
The two energy scales measure slightly different things: SAP looks only at the fixed elements of the building and is the same wherever the property is located. All homes built to the same design should have exactly the same SAP and new regulations mean all new homes must display their SAP rating. This should be at least 80-85. The NHER rating is more meaningful, as it includes various location-specific elements (e.g., whether the building is South-facing or sheltered from wind by other buildings) and so reflects actual running costs.
The NHER Scheme is administered by National Energy Services Ltd. Various organisations are franchised to deliver ratings under this scheme, which also offers SAP ratings and predictions of annual running costs. Contact the National Home Rating Scheme on 01908 672787 for details of a qualified NHER assessor to carry out an audit in your area. An assessor carrying out an NHER rating should give you advice on how to improve the energy efficiency of a building and a typical building may receive something like the following table.
Comparative Effectiveness of measures.
Measure taken / Annual fuel bill savings (£) / CO2 emission reduction (kg)Draughtproofing / 1020 / 125250
Loft insulation / 6070 / 750880
Windows: / plastic secondary / 1525 / 190320
whole unit / 1535 / 190450
Walls: / cavity insulation / 6070 / 750880
internal / 4555 / 590720
external / 5585 / 7201120
Floors insulation / 515 / 60190
Lagging hot water pipes / 510 / 60125
Shelf over radiator / 510 / 60125
Foil behind radiators / 510 / 60125
from: The Ethical Consumer Issue 30, Jan/July 1994, Green Buildings Special
Energy Conservation measures
Around 60% of the energy consumed by a building is used for heating so it is very important to undertake all the insulation and draught-proofing measures that you can afford.
Draughtproofing
This is the easiest work to start with, and can be very effective, as 1550% of heat loss can be due to draughts.
a)Windows: Unless these are sealed, draught spaces can usually be found round frames and sections. A variety of sealing strips are available, including silicone rubber tubes for sash windows. Metal strips last longer but cost more. There are several firms offering sash window renovation schemes which reduces energy loss associated with draughts while keeping the original timber windows. As an energy conservation measure it qualifies for the low 5% VAT rate level. Some companies are listed in the useful contacts section.
b)Doors: Draughtpreventing strips can be fixed to the top and sides of doors, and a brush type of strip to the bottom, which will sweep over uneven floors and carpets. Screening letterboxes and even keyholes can be helpful. A porch on the outside (or inside if there is space) can act as a draughtproofer and insulator, preventing direct access of cold air.
c)Floors: Sealing spaces round skirting boards with acrylic or silicone sealant or with wood coving can be done. Gaps between floorboards can be filled with soft string coated with sealant, or by thin lathes of wood.
Ventilation
Draught-proofing is essential to save energy but obviously homes will need some ventilation at times. This can be obtained by opening windows, leaving chimneys unblocked even if open fires are not used, and special ventilation devices. Extractor fans should have shutters to prevent draughts when they are off. In a new building, natural stack ventilation can be provided for. This enables hot air to rise naturally and come out at the top, under the eaves or elsewhere.
Plants(1)
Indoor plants such as bamboo plam, rubber plant, areca palm (yellow or Butterfly palm), english ivy, dwarf date palm, boston fern, peace lily, kimberley queen, chrysanthemum morifolium (florists' mum), gerbera daisy, umbrella tree and spider plant are recommended for the removal of pollutants from indoor air.
Insulation
a)Roofs: Loft insulation is the most important measure to start with, as it is relatively simple and will usually pay for itself in energy savings. At least 10 inches depth of material should be used. Choose a non-toxic material such as mineral wool (fibreglass or rock wool), vermiculite (mineral) or cellulose fibres (Warmcell being an example). Sheep’s wool may also be available.
Flatroofs: These are more difficult to insulate, but can be done internally or externally. The latter is simple in principle, but it is difficult to find environmentally friendly materials. Internal insulation can be done by either covering the ceiling with insulation boards pinned through the plaster to the joists and papered or painted over, or by fixing a false ceiling on battens, and installing mineral wool or other insulation in the space between, using a vapour barrier.
b)Floors:Resurfacing with boards or other surfaces may be appropriate (cork tiles). A good carpet with a felt or rubber underlay, or layers of newspaper, can be sufficient. If you have to take floors up for any reason, underfloor insulation can be fixed, hung in netting from the joists.
c)Windows: Doubleglazing can reduce heat loss through windows.. This can vary from cheap DIY methods and materials, to expensive replacement sealed units. Heavy lined curtains with a pelmet, and reaching the length of the windows are quite effective:
Plastic film sheeting is the cheapest “doubleglazing”, using clingfilm and sellotape. Clean the window and frames first, and let them dry off. This method will only last one winter and is rather fiddly. Clear polythene can be used, attached with doublesided adhesive tape. It is more expensive than clingfilm but lasts longer. A more permanent method is to use a pane of glass or plastic, screwed or fixed with a magnetic strip to the frame. Replacement sealed units are probably not worth fitting unless the window needs to be replaced anyway. They can be composed of low emissivity glass and contain argon, so reducing heat loss even further. Get a number of estimates before arranging for this to be done and avoid PVC if possible (consult AECB for alternatives). Several sash window renovation companies offer renovation of existing frames with installation of draught cutting systems and sometimes double-glazing - a few are listed in the resources below.
d)Walls: Much heat can be lost through walls, which may be cavity or solid.
i)Cavity(most houses built after 1930): Insulating materials can be blown into the cavity. Choose a nontoxic material (see “Roofs”). Avoid ureaformaldehyde foam, which can give off toxic fumes of formaldehyde.
ii) Solid:Best carried out when the walls need renovating anyway, as the procedures are expensive. Insulation may be internal, either of prefabricated thermal boards with a vapour check, which are fixed to the plaster with adhesive and screw plug fittings, or by fixing battens to the walls and board to these, filling the space between with insulating material and a vapour check between the insulation and the plaster. External insulation alters the appearance of the house, so planning permission may be required. Expanded polystyrene or mineral fibre slabs can be used but need a durable cladding.
Water heating
This is usually the next biggest consumer of energy after space heating. There are two main types, storage and instant:
The choice depends on the number of people using the system, the frequency of use, and the amounts required. If you have a southfacing roof, some money to spare, and would like to set an example of our Quaker witness, solar panels for water heating provide an environmentally benign method of water heating. These systems are becoming cheaper and more efficient, and if you have a DIY expert can be installed without too much expense. A storage tank is needed for solar heating.
Duncan Wood, in EcoRenovation by Edward Harland, 1993
Storage heater (left) and instantaneous heater (right).
Many central heating systems also provide hot water by heating a storage tank full of water. If you have a storage tank, it needs to be well insulated and have a thermostatic control so that the temperature can be set to the lowest which is comfortable for washing. Insulating your hot water tank and lagging the hot water pipes will save money as well as energy.
When you replace your boiler, you may be able to save energy by installing a combination boiler that heats the water directly when a hot tap is turned on. You might also consider installing several individual water heaters in different areas. They can save on heat loss from pipes, and on the wastage of water and energy when hot taps take a long time to “run hot”.
Miscellaneous measures
A conservatory will act as a buffer, collecting solar energy during the day and trapping escaping heat at night. It should face east, to get the morning sun, or south.
Silver foil behind radiators on an external wall reflects heat back into the room. A shelf above the radiators does the same, and prevents the heat rising up to the ceiling.
Only heat the rooms that are needed, and keep doors shut between different rooms. Turn off lights when not in use, or not needed (e.g. during Meeting for worship!).
References and useful resources
BRECSU, Garston, Watford, WD2 7JR, tel. 01923 664258, free leaflets on a variety of subjects
Centre for Alternative Technology, Machynlleth, Powys SY20 9AZ; website:
Government Environmental Department. An information pack from the ‘Are you doing your bit? campaign can be obtained free by phoning 08457868686 or website:
AECB (Association for Environment-Conscious Building) Nant-y-Garreg, Saron, Llandysul, Carmarthenshire SA44 5EJ
(1)How to Grow Fresh Air: 50 Houseplants that purify your Home or Office by Dr. B. C. Wolverton. Penquin 1996.
For energy rating survey:
National Home Energy Rating Scheme: 01908 672787
Your Local Energy Efficiency Advice Centre Freefone 0800 512 012
Colin Bemrose - energy consultant specialising in energy use in churches and community buildings - 9 Wordsworth Road, Rugby, Warwicks CV22 6HY Tel 01788 810978 or 0411 609325 email:
Sash Window renovation companies:
Sash Window Workshop 2000 - based in Berkshire and serve London and the South - offer renovation (using FSC timber), draught exclusion and double-glazing of existing window using specialist on site technique. Tel: 0800597 2598; website:
MH Joinery Services - based in Yorkshire - offer renovation, draught exclusion and double-glazing. Tel: 01423 562999 website:
Sash Window Specialists - based in Birmingham and serve the Midlands - offer renovation and draught exclusion. Tel: 07812 105917; website: freespace.virgin.net/s.free
Ventrolla - based in Berkshire - won Design Council Award for renovation and draught exclusion.
Tel: 0800 783 8593
(This Building Sheet is based on Quaker Green Concern's The Witness of Our Buildings Information Sheet I dated July 1997. We are grateful to Peter Warm of AECB for help in updating this Sheet, which also uses information from the very useful website of the National Energy Foundation:
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Case Study: Dorking Meeting House
Dorking Friends Meeting House, built in 1850, is a single storey building with the following rooms to the front:
·Entrance Lobby
·Small office to the right, used by Age Concern
·Small meeting room to the left
To the rear of the building there are the following rooms:
·Main meeting room.
·Small hall, divided from the meeting room by a moveable partition.
·Kitchen and storage area.
·Toilets.
The rooms to the front have a low roof and those to the rear a high roof. The ceiling height in the rear part of the building is considerable, particularly in the main and small halls.
Usage of Rooms
The use to which each of the rooms within the building is put varies considerably. The Age Concern office to the right hand side of the lobby is used most week days, and so needs to be heated most of the time.
A playgroup makes use of the small hall and kitchen areas during weekday mornings and early afternoon until 1 or 2pm. This area therefore also needs to be heated most of the time.
The small meeting room to the left of the lobby is not used as much, and would not need to be heated when the other rooms require warmth. The same applies to the main meeting hall. This area has a high ceiling and draughty sash windows, and represents the highest demand for heat when the system is on