Following on from low and no cost improvements you should now be looking further into reducing your energy consumption by making medium cost improvements. These improvements involve spending more money than before but the reduction in your energy bill will be noticeable. They generally involve maximising the insulation of your house, and only once this is done then you can then move onto higher cost improvements.
The above picture is taken from bclinsulation.co.uk and shows the estimated heat loss through main surfaces of a house.
This article will discuss the improvements you can make to reduce the energy loss through your home. Insulating your home is not just about keeping your house warm in the winter; it is also about keeping it cool in the summer.
Around a quarter of heating in an un-insulated house is lost through the roof. Hopefully you should have some insulation already in your loft. However this may be old and ineffective and or not adequate enough in terms of thicknesses and thermal properties. You can either start from scratch in replacing or installing new loft insulation, or you can top up your insulation to give it the required R value it needs, (if you know).
An ‘R Value’ is what describes the thermal properties of an insulate material. There are many different thicknesses and materials used for loft insulation, and this is where this number comes in handy! The National Insulation Association (NIA) recommends an R value for loft insulation to be between 6.1 and 7 K.m2/W (K.m2/W means Kelvin x Metre squared / Watts, Kelvin is another measurement of temperature). You will find that loft insulation materials in the shops rarely have an R value of 6.1-7 as a single material, you will however, have to thicken your loft insulation layer up using a few blankets or quilts more of loft insulation.
The cost to you if you were to install this yourself would be between £200 -£350. However, you should see this money come back to you within 2-6 years depending on what you have spent on installing it in the first place. As loft insulation works well for at least 40 years, you will have the luxury of 30+ years of paying anywhere between £45 and £150 a year less for your heating bill. There is a lot of information to hand, on DIY loft insulation over the internet, DIY stores, such as B&Q, offer DVD’s or brochures to instruct you on how to install loft insulation yourself and what to look for.
Do it yourself loft insulation materials come in the form of quilts or blankets. However, there is also ‘blown’ insulation that you could have in your loft, but only a professional installer can install this. This is due to the complexity of the strength of your roof and specialised equipment needed. Blown insulation is made up of volcanic rock and by products from industry. It is naturally then flame retardant due to the volcanic rock and is also using treated waste product from industry that otherwise would have gone to landfill.
Generally, houses that have been built after 1920 have gaps between the outside and inside walls. This is known as a cavity. Since around a third (diagram 1.) of your heating is lost through your walls it would be a good idea to have cavity wall insulation installed.
It costs around £500 to install, or around £250 with a subsidy grant, and saves you £100+ on your yearly heating bill. The funding for the subsidy comes from the major energy suppliers under the Governments Carbon Emissions Reduction Target. Around 50% of the cost is available to anybody regardless of living circumstances. 100% is available to anyone over the age of 70.
Cavity wall insulation is not a DIY job but for a professional installer to do. It should only take around a couple of hours to complete the installation.
According to the Energy Savings Trust (EST) [1] installers must be registered under the National Insulation Association (NIA), the Cavity Insulation Guarantee Agency (CIGA) or the British Board of Agrement (BBA). The EST also says that you should make sure that the installer has signed up to a code of professional practice provided by the NIA and the installation is guaranteed for 25 years by CIGA.
The diagram on the left shows a brickwork pattern that likely indicates that you have cavities between your walls. The diagram on the right has a two directional brick work that means that it does not have cavities within it.
My wall is like the diagram on the right, then how do I insulate my walls?
This type of insulation is known as solid wall insulation. You have two options; either the internal or external walls can be insulated. Both have their advantages and disadvantages.
Internal tends to be cheaper than external. Both are ideally installed when important renovation or refurbishment is taking place. You will lose around a centimetre of space internally due to the boards and when installing from the inside, everything needs to be taken off and refitted after installation.
Internally, solid walls can be insulated with rigid insulation boards or stud walls. Rigid insulation boards are made out of a plastic. Stud insulation is made up of a studwork frame of wood or metal and in filled with mineral wool fibre.
Externally, solid walls can be insulated by a layer of insulation material and then covered by cladding or rendering. For installers and information visit the Insulated Rendering and Cladding Association Website [3]
Energy Efficient Boilers
Energy efficient boilers or condensing boilers are so named because of the process they use in recycling waste hot flue gas back into water.
If your existing boiler is more than 15 years old it is likely to be highly inefficient, or what’s called a G rated boiler (less than 70% efficient). In comparison, energy efficient boilers are 90%+ efficient, and so are given an A rating. You could save around £240 per year if you were to upgrade from a G to an A.
The cost of installation is around £1000+ depending on the existing situation. So the overall payback period would be around 4-5 years.
It is recommended to shop around for the best quote before going ahead with the installation. Anything gas orientated should be handled by someone who is Gas Safe (which used to be known as CORGI registered.)
Unfortunately, the UK boiler scrappage scheme ended on the 31st March 2010, so now there isn’t any grant available for this particular type of installations. However if you want to tie in a medium cost and higher cost improvement, how about considering replacing your boiler with a wood stove or ground source heat pump? A new scheme that replaces the Low Carbon Buildings Programme, called the Renewable Heat Incentive is set to be in place by April 2011 [4].
[1] http://www.energysavingtrust.org.uk/
[3] http://www.inca-ltd.org.uk/register-members.htm
[4] http://www.decc.gov.uk/en/content/cms/consultations/rhi/rhi.aspx
Useful Links
Energy Saving Trust – www.est.co.uk
Low Carbon Buildings Programme – www.lowcarbonbuildings.org.uk
Insulated Rendering and Cladding Association Website – http://www.inca-ltd.org.uk/register-members.htm
