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Below are some of the most frequently asked questions we receive, we keep this section updated constantly to ensure you have access to the information you require.

Solar Energy

Can I mount solar panels on a wall instead of a roof?
It is possible to put solar panels on a wall, but it is important to note that performance will be lower and you must endeavour to mount them on a wall that sees sunlight at some point in the day.

Do I need to apply for planning permision before I install renewable technologies such as solar panels or wind turbines?
Issues surrounding planning permission are unique to every home. If for example, you live in a listed building you will require planning permission before making any changes to the exterior of the property. We would advise you to contact your local authority for tailored advice on your situation before purchasing a renewables system.

How do Photovoltaic panels work?
Photovoltaic panels convert solar radiation into electricity. The cells within the PV panel consist of one or two layers of a semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers, causing electricity to flow. The intensity of light directly relates to the flow of electricity. PV systems create no greenhouse gases, saving approximately 325kg of carbon dioxide per year for each kWp installed.

How long can I expect till I receive a return on my investment in a solar water heater?
A typical solar water heating system is a sound investment and will typically pay back the initial investment in 8-10 years (a conservative estimate) through savings you'll have made in water heating.

How many solar panels will I need to make a difference on my emissions and energy bills?
Generally, one solar panel will provide enough energy to heat a 100 litre hot water cylinder. A home with a 200 litre cylinder will require 2 panels.

How much can I expect to offset my carbon footprint by installing a solar water heater?
A solar water heater can be expected to reduce your home emissions by up to 15% a year. That equates to about a tonne of C02.

How much can I expect to save on my energy bills by installing a Solar Photovoltaic (PV) panels on my roof?
In a typical year, a solar Photovoltaic system will generate around 800kWh of electricity kWp. This is equivalent to around a 33-50% saving off your electricity bill every year.

How much money can I expect to be awarded through the Low Carbon Buildings Programme?
The money available through the LCBP is split into two phases, one to provide grants for homeowners and one for charities and the public sector. Homeowners can expect to receive a grant of up to £2,500, depending on the type of technology installed. As for the 2nd phase of the LCBP, applying to public sector buildings such as schools, hospitals, housing associations and local authorities, figures are not available on what applicants can expect to receive, but applications are being accepted now, with awards expected to be made up to mid-2009. For more information, visit the BERR's LCBP website, at

How much water do I have to be using to make a solar water heater a good investment?
A typical 2 person household where each person has a shower a day can make substantial savings in water heating bills, and reduce your carbon footprint.

I've heard that solar panels may not be suitable for all properties. How do I check if I can install them on my roof?
A solar panel system will require about 3 to 4m² of roof space so you should ensure that this space is available on your roof before you buy a system.
It is also important to ensure your roof has unobstructed sight of the sun from 9am until 3pm from February through to October. The panels should be installed at an angle of 30°- 50° to the horizontal and directly facing the sun at some stage between 10am and 2pm.

What is the difference between solar photovoltaic panels and solar thermal panels?
Photovoltaic panels generate electricity to be used anywhere in the home direct from sunlight. Solar thermal panels use the suns energy to heat water.

Will a solar water heater work with my existing boiler?
Solar water heaters will work with almost any existing boiler. Although we would recommend an individual assessment or survey which might suggest the best option is to replace your existing boiler to reduce your energy consumption and save on your bills.

Will the UK climate support the use of solar panels?
The solar panels we supply are not contingent on the UK climate; they will work in cold and cloudy weather. Solar thermal panels use light to produce energy rather than heat, so hot water will always be available. Solar Photovoltaic panels use light to generate electricity rather than heat so generation will always occur as long as there is light. Obviously, the brighter the light the more electricity will be generated.

Cavity Wall Insulation

Are the cavity wall insulation installers trained?
All installers undergo training by the system supplier to ensure they are competent in CWI and carry a training card. Please feel free to ask to see the training card.

Are there any negative aspects of installing cavity wall insulation?
Modern materials and installation methods mean that there are very few problems with cavity wall insulation these days. It is more important to ensure that the wall at which cavity insulation is to be installed is in good condition and there are no materials internally which may allow water to cross into the internal wall.

Can cavity wall insulation be installed from the external side of the wall?
The installers must undertake checks before and after installation on both sides of the walls, including the checking of any heating appliances. Therefore it is essential that they have access to the property.

Do I need to prepare my home or walls before installation?
Cavity wall insulation is installed by drilling tiny holes in walls and blowing insulation in through them. The process of drilling these holes creates some vibration in the property; it would therefore be wise to remove ornaments and pictures from walls due to be worked on. Keeping pets indoors is also advisable. The installers will need access to the entire property so you should ensure all walls are accessible. If one of your walls are located on a boundary it would be wise to advise your neighbour that the installers may need to work on their property at some point, and it would be wise to obtain their permission.

Does the installation process create a lot of mess?
The drilling process will create a little dust, which will be cleared at the completion of the job. It would be sensible to remove vehicles from the drive and things close to the walls, which will also improve the installer’s access for equipment and tools. It would also be advisable to inform the neighbours and ask them to keep their windows closed and take their washing in during the process.

Does the insulation need to be dense?
As the insulation is contained within a masonry wall, it doesn't have to be 'dense'. For insulation and other purposes, a light density is better. Before installation, the installers will undertake a quality test to ensure the insulation will go into the wall at the right density. The amount of material used will also be noted, to ensure that sufficient insulation has been installed.

How can I insulate my home if it has solid walls?
It is possible to insulate walls which have no cavities, but the process is more complicated. The two most commonly used methods are external cladding or internal lining (dry lining), or using wall battens. External cladding involves applying insulating material to external walls and then adding a protective waterproof finish. Internal insulation can be bought in rolls and applied like wall paper, before being painted over for decorative purposes. Wall battens are used by filling the space between them with insulating material and covering with a plasterboard finish. Steps must also be taken to prevent moisture build up behind the new insulation.

How do you check that the insulation has filled the cavity?
Each cavity wall system has a defined pattern of holes, which has been tested to verify that it results in a complete fill. Most systems have an automatic cut out, which actuates when the adjacent wall area is full. There is tolerance in the injection pattern so that the material will flow past the next injection hole.

How do you tell if my house is suitable for cavity wall insulation?
Before installation, an assessment of your property will be undertaken to confirm that it is suitable for insulation. This assessment can be carried out by a surveyor or the technician before installation.

How long does it take to install cavity wall insulation?
On average, the installation process will take around two hours. This of course, depends on the size of the building to be insulated and how easy it is to access the cavities.

How long will the insulation last?
The BBA has certified this product and agree that it will last the life of the building.

I live in a semi detached house, how do you prevent insulating my neighbours cavity?
The installers will insert a cavity barrier at the party wall line. This is usually a length of bristle brush which goes inside the cavity and will not be visible.

What are the maintenance or servicing requirements of cavity wall insulation?
There is no additional building maintenance required after installing cavity wall insulation, but you should still maintain the rest of your building to a high standard.

What is a CIGA guarantee and how do I get one?
The Cavity Insulation Guarantee Agency (CIGA) provides independent 25 year guarantees for Cavity Wall Insulation fitted by registered installers in the UK and Channel islands. You do not need to do anything to receive this guarantee; we will submit the Guarantee application. The Guarantee is posted to you within days of the application being received at CIGA. Keep it safe.

CIGA is non-profit distributing; its only function, is to stand as guarantor for the promises set out in the Guarantee. It has the resources to meet the promises made in the Guarantee. All professional approved installing firms are members of CIGA and can apply for a CIGA Guarantee, for properties built with traditional cavity walls. You should insist on a CIGA Guarantee, since nothing else can give you the level of assurance to which you are entitled.

What material goes into insulating a cavity wall?
The most common forms of cavity wall insulation are mineral wool fibre and polystyrene beads. Mineral wool fibre is a water resistant material made from molten rock spun similar to candy floss, or glass fibre. This is installed by being blown into the cavity. Polystyrene beads are an adhesive version of those found in bean bags and again, can be blown into the cavity.

What will be done if installation is through a painted wall?
Usually, we will paint over the injection holes. However, even if the original paint is used, it may not match due to weathering. So it may be necessary for you to consider painting the area, after the mortar has dried.

Will cavity wall insulation make my home noticeably warmer?
If your heating is not controlled by a thermostat, you should notice a difference after having cavity wall insulation installed. However, if you have a thermostat, it will cut out the heating at the same temperature, so you may not notice the difference in the room with the thermostat. You should however, find that the temperature in other parts of your house improves.

Will the installers fill in the holes drilled?
Yes, the installers will fill all the injection holes with mortar to match the existing wall as closely as possible. He will use a mix that closely matches the existing colour and texture. On pebbledash finishes, pebbles will be applied to the surface to match the existing finish. After weathering, the holes are difficult to see.

Will ventilators in the external wall be safeguarded?
Ventilators supplying combustion air to fuel burning appliances and those which ventilate below timber doors must be safeguarded. The installers will investigate them to check they are already sleeved. If they are not, they will be removed and sealed around them to stop blockages by the insulation. Any redundant vents, such as cavity vents or vents that are used to supply air to open fires in bedrooms may be closed off and filled. The installer should discuss your options with you.

Energy Use

How do you define a 'zero carbon' home?
The Energy Saving Trust estimates that 27% of the UK’s carbon dioxide emissions come directly from the way we use energy in our homes. The UK Government was the first to set legally binding emissions targets for all newly built homes in England and Wales. Their target is for all homes to be ‘carbon neutral’, or ‘zero carbon’ by 2016. A home can be considered ‘zero carbon’ when the emissions it produces throughout the course of a year are offset by the energy saving measures installed.

Making your home ‘zero carbon’ standard is possible through employing a mix of design improvements such as improved air tightness and thermal bridging, energy saving techniques such as the installation of new insulation in the loft and wall cavities and the use of A-rated white goods, and the installation of renewable technologies such as solar panels. It is estimated that implementing just some of the above measures could save you an estimated £300 per year on your energy bills, and will also increase the value of your home should you come to sell it on.

How much of the energy used by this country is currently generated through renewable sources?
The current amount of energy generation in the UK through renewables is relatively low, at around 4.2%. However, the Government are constantly reviewing their position and have set a target of 20% generation by 2020. However, due to an acknowledgement from the Prime Minister that admits that a 60% reduction in emissions by 2050 may not be enough, you could expect the demand to be put on renewables to increase.

I run my own business, are there any carbon calculators SIG Energy Management recommend I use to estimate the carbon footprint of my business activities?
There are hundreds of carbon calculators available online from various soures. We would recommend that UK businesses adhere to UK government legislation on emissions reduction and would therefore advise that any business seeking information on measuring carbon emissions should read the guide produced by Defra, available at

Is there a calculator available that will estimate my emissions from other sources as well as energy use?
For small businesses, SIG Energy Management would again recommend reading Defra's guide on Environmental Reporting, available here, For homeowners, the Act on CO2 Carbon Calculator offers an excellent opportunity to measure emissions as a result of your home, your car journeys and air travel. This can be accessed here:

Should I be worried about global warming?
Global warming has the potential to radically change the way each and every one of us live our lives if it continues unchecked. The only way it will continue unchecked is if we continue to do nothing about it. The process of global warming is the warming of the earth’s atmosphere caused by trapped greenhouse gases such as carbon dioxide. These trapped, warming atmospheric gases in turn warn the surface of the earth and cause climate change. Every action, however small, such as some of those suggested on this website will help reduce the release of greenhouse gases and therefore help to reduce the threat of climate change.

What are the most effective methods of saving energy in my home?
The ten most effective methods for making your home more energy efficient are listed below. Remember; even if you just do a few of these you can still potentially make savings of up to £300 a year off your electricity bills.

  1. Insulate your cavity walls. Installing cavity wall insulation is far cheaper than the installation of renewables such as solar panels, and has a shorter payback period. This means that installing cavity wall and loft insulation could bring you instant savings of up to £160 per year.
  2. Check your boiler. Boilers over 15 years old will be highly unreliable and costing you money on energy that goes to waste. The best solution is to replace your existing boiler with a new energy efficient one, meaning not only will your homes be reducing its energy consumption, but you could be saving around a third on your heating bills.
  3. Use your freezer efficiently. Ensure you don't leave the door open longer than necessary, as cold air will escape. Avoid putting hot food into the fridge, defrost the freezer regularly and check the door seals are working properly.
  4. Buy energy efficient appliances. When buying a new electrical good for your home, nowadays there is no excuse not to go for an energy efficient appliance. All kitchen goods, TV’s, DVD players right down to light bulbs now have energy efficient ranges which will reduce your electricity bills as well as reducing your energy usage.
  5. Insulate your hot water tank. Insulating jackets for hot water tanks cost a few pounds but the benefits will be seen in just a few months when your heating bills are reduced. Best estimates are that a properly insulated hot water tank could reduce your bills by up to £20 a year.
  6. Use your curtains. Once winter begins to set in, close your curtains at dusk to reduce heat loss through your windows and keep your home warm.
  7. Install energy efficient light bulbs. Costing as little as £3.50, energy efficient light bulbs last up to 12 times longer and for each bulb you fit, you can save up to £9 on your annual electricity bill.
  8. Exclude draughts. Seal up gaps under skirting boards with beading or mastic sealant to further prevent heat loss, potentially saving up to £20 off your bills every year.
  9. Cut heat loss through double glazing. Installing double glazed windows has the potential to save you up to £100 per year on your heating bills.
  10. Carry out a home energy check. A new Government requirement means all homes on the market must have an energy performance certificate as part of their home information packs. Having your home surveyed by an energy-saving professional before completing a HIP will allow you to make changes which will make your home more energy efficient, decrease your bills and increase the value of your property.

What difference does energy saving in one home make to climate change?
Scientists are united in agreement that climate change is happening, and that everyone has a part to play in the reduction of harmful emissions. Figures suggest that collectively, UK homes emit around 27% of our carbon emissions yearly, more than both industry and transport. If every individual home took just one step to bringing down their emissions, whether it be through recycling food packaging or installing a solar panel system, we could dramatically reduce the percentage total housing accounts for in emissions and help reduce the threat of climate change.


Can I insulate a flat roof?
It is possible to insulate flat roofs, one of the best ways being to add an insulating layer externally and then a new, weatherproof layer on top of that.

What is Combined Heat and Power (CHP)?
Heat is a by-product of electricity generation and typically would go to waste. Combined Heat and Power (CHP) captures and utilises this heat, thus cutting down on waste. CHP can increase efficiency of fuel use to more than 75 per cent, compared with conventional generation which stands at around 40 per cent. The closer the CHP is located to the point of consumption, the lower the amount of lost energy.

What is the benefit of insulating the floors of my property?
It is estimated that heat loss through floors amount to about 8%, less than the roof and walls so it is advisable to insulate those before considering the floor. It is only really necessary to insulate the ground floor as heat loss from the other floors benefits the floors below. However, it’s important that air is allowed to circulate to prevent damp. In addition, heat loss through a solid floor can be reduced by fitting underlay or wooden flooring.

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