Energy Efficiency

Energy Efficiency

Climate change is one of the most important reasons why we need to be more efficient with our energy use and reduce our impact on the environment. By making simple changes in our behaviour such as the way we heat our homes and use electrical appliances, we can all help to reduce the impact of climate change on the environment for future generations. Eventually fossil fuels will run out, as they are afterall a finite resource. In 2006, for the first time, Britain began importing much of the gas needed for heating and electricity generation. As a result of this, many people have seen their fuel bills rise significantly. Adopting an energy efficient lifestyle will not only save money and reduce our contribution to climate change, it will ease the pressure on UK energy reserves. Using energy more efficiently is a major factor in reducing our impact on climate change. Energy efficiency is not just good in terms of the environment, it also saves you money.

How can we be more energy efficient?

When it’s cold outside we instinctively grab our coats and wrap up warm to insulate ourselves. Yet with our homes we are more likely to do the opposite and only provide minimal amounts of protection against the outside cold. Imagine wrapping your house up in a woolly hat and scarf to retain the heat – this would help keep it warm, just as we do with our bodies.

In order to save money by reducing energy use and our impact on the environment, it is essential to ensure our homes are adequately insulated. For a comfortable, warm and energy efficient home, it’s important to strike the right balance between insulation, heating and controlled ventilation.

Insulation is one of the most important elements of any refurbishment project

Cavity Walls: In an average semi-detached house with unfilled cavities, approximately 35% of heat is lost through the walls. That’s £35 out of every £100 spent on fuel bills! Insulating your walls is one of the most cost effective ways of improving the energy efficiency of your house and with the savings you’ll make, you should recover your costs for the work within just a few years. There are discounts and grants available for cavity wall insulation, click here for more information.

Solid Walls: Solid walls lose heat more quickly than cavity walls, which could be up to a staggering 45% of the heat being produced, but it’s much more difficult and expensive to insulate them. You can use internal or external insulation on solid walls but both of these options have always proved to be disruptive and expensive. New products have been developed to help overcome this, which we will be demonstrating in one of our properties where we are insulating an internal party wall using a product called Spacetherm.

Insulate your loft

We all know that heat rises but did you know that if your home has inadequate loft insulation, you could be losing up to 25% of heat through your roof. Current building regulations require a depth of over 250mm. Mineral fibre can be laid between the joists, then across the joists to achieve the required depth. As well as traditional mineral fibre, there are different types of insulation material available such as recycled newspaper and sheeps wool, which can also be easily blown in between the rafters.

Roof spaces require ventilation to prevent a build up of condensation, which can cause timber to become wet and start to rot. All pipe work should also be insulated to help save you money, reduce heat loss and prevent the risk of them freezing.

Although loft insulation is a fairly easy DIY measure, it is recommended to consult an expert for advice before going ahead.

Your hot water cylinder is another area where heat can be lost. By fitting a thick insulating jacket and insulation to the pipework, you could reduce your heat loss and fuel bills even further. The cost of a new jacket is approximately £20 and is fairly simple to fit.

There are a number of schemes that can help finance loft and cavity wall insulation and Huntingdonshire District Council can provide advice and information about the full range available. If you receive certain income or disability related benefits, you may be eligible for a 100% grant.

Heating controls

Good heating controls are an essential part of your central heating system. A room thermostat will tell your boiler to switch off once its set temperature has been reached and to switch back on again if it falls. A digital version gives you more accurate control. You can even opt to have a programmable room thermostat allowing you to choose the temperature you require and precisely what time you would like it to come on. Individual thermostatic radiator valves will lower the heat demand in each room so you’re not overheating rooms you don’t use and wasting energy and money. These work alongside your room thermostat, not instead of.

A programmer will allow you to set the boiler to come on and off at different times of the day to control your heating and hot water demands. If you have a hot water cylinder to store your hot water, this should have a thermostat attached to it which regulates the temperature level. This should ideally be set at 60 – 65ºC. This is hot enough to kill off harmful bacteria but not waste energy or risk scalding.


Approximately 18% of heat is lost through single glazed windows even though installing double glazed windows is costly, it is worth considering if your existing windows need to be replaced. Double glazing saves you around £120 per year and also reduces noise and condensation levels of your house. Trickle vents are now fitted as standard, allowing for controlled ventilation.


One of the quickest ways to reduce electricity usage and CO2 emissions is to change all old-fashioned light bulbs to energy efficient ones. The Green House Project takes this a stage further with the St Ives property by having LED lighting to reduce energy demand even further.


Both our Green homes will contain a range of high energy efficient appliances – none of which will have a standby button. This will save each house around £37 per year. But UK wide, it could save the equivalent of the annual output of a 700MW power station – that’s how much is wasted a year by households keeping appliances on standby.

Both houses will have an indicative smart meter, showing real time electricity usage information.

Draught proofing

Draught proofing can be fitted quite easily around windows and doors and is a fairly low cost measure. Approximately 12% of heat loss could be saved if draught proofing is fitted. A draught excluder on your letterbox only costs a couple of pounds, but makes a big difference.

Ventilation is important to achieve a healthy number of air changes within a home, but this must be controlled via measures such as vents, trickle vents on windows, specialised ventilation systems and extractor fans.

Sample pay back periods for energy efficiency measures

  Annual savings Installed costs Pay back CO2 saving
Roof insulation Around £150 Around £250 Around 1 year 800 kg
Cavity wall insulation Around £115 Around £250 Around 2 years 610 kg
Lighting Around £40 Around £30 Around 9 months 172kg
Solid wall insulation Around £380 Around £650 Around 6 years 2 tonnes
Hot water jacket Around £45 Around £20 Around 6 months 190 kg

Source: Energy Saving Trust