Green home improvements guaranteed to reduce your energy bills

With gas and electricity bills soaring, it's worth thinking about what can be done to make your home more energy efficient.

If you're renovating, there are 'green' home improvements that can cut both your carbon footprint and your energy bills.

Let's take a look at what's possible and how much money you can save on your bills.

With around 25% of a home’s heat lost through the roof, installing loft insulation is a great way to improve the energy efficiency of your property.

There are several different types of loft insulation to choose from. 

At one end of the scale, if you have easy access to your loft, and there are no issues with damp or condensation, you can use rolls of mineral wool insulation to do the job yourself.

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Simply put the first layer between the horizontal beams that make up the floor of your loft, with the next layer laid at right angles to cover the joists.

A variation on this is loose-fill loft insulation, which is made of cork granules, cellulose fibre or mineral wool, and is poured between joists to a depth of 270mm.

Alternatively, you can pay a professional to fit rigid insulation boards between the rafters in your loft that make the roof.

However, doing this is not only more expensive than using mineral wool insulation, it's also less efficient.

In the past, foam insulation spray has been used as a way to insulate lofts, particularly in cases when the roof is leaking, but this approach is not recommended, as many lenders will not advance mortgages on homes with this type of insulation.

When insulating your loft, it's important not to block its ventilation, such as vents, grilles or airbricks, as air needs to be able to flow in and out to prevent problems with damp.

Loft installation typically costs around £640 for a semi-detached house, and it could cut your energy bills by as much as £355 a year, making it one of the quickest energy efficiency improvements on which to break even.

With a third of heat escaping through uninsulated walls, putting in cavity wall insulation can have a significant impact on your energy bills.

If you home was built during or after the 1990s, it is already likely to have cavity wall insulation.

Properties built after the 1920s are likely to have cavity walls, namely two walls made of brick, or brick and concrete blocks, with a gap in between them.

By contrast, homes built before this date may have a single solid wall made of brick or stone.

You will want to get input from a professional to be sure, but as a general rule, if the bricks have an even pattern, with all of the bricks laid length ways, you will have cavity walls.

Cavity walls can be insulated by drilling holes in the outside of the wall and injecting insulation material into the holes, before sealing them up again. 

You will need to hire a professional to do this, but the good news is that they can typically complete the job in around two hours.

Insulating cavity walls costs around £1,000 for a semi-detached house and can knock around £395 off your annual energy bill.

Installing ground floor insulation can reduce your energy bills by around £110, based on a semi-detached home.

If you live in an older home with a suspended timber floor, you can use mineral wool insulation. 

Unless you have access to the floor through a cellar, you will need to lift the floorboards and lay the mineral wool insulation, supported by netting, between the joists.

Alternatively a remote-controlled robot can be used to apply spray foam insulation to the void space underneath the floorboards, which means you do not need to lift them up.

The cost of putting in floor insulation ranges from £1,600 to £2,900, depending on the method used.

If you live in a modern home with concrete floors, you can have rigid insulation foam fitted if the floor is being replaced.

Alternatively, rigid insulation, such as EPS sheets, can be installed on top of the concrete floor, with chipboard flooring placed over it, although this will raise the level of the room.

Other steps you can take to insulate your floor include using sealant to fill any gaps between your floor and skirting board, while laying a thick carpet can also help prevent heat loss.

If you are putting in a new kitchen, installing low energy appliances can help to make your home more energy efficient.

All appliances are given an energy rating from A to G, with A being the most efficient, or A+++ to G, with A+++ being the best.

For example, an A-rated dishwasher costs around £45 less a year to run than the lowest rated one, while having an A+++-rated tumble dryer can save £75 a year compared with the least efficient one.

Installing smart home devices can also help you make your home more energy efficient.

Smart thermostats, such as Hive Thermostat, enable you to control your home’s heating remotely through your mobile phone.

As a result, you can save money by making sure you're not heating your property when you're not there. Handy if you forget to turn your heating off before leaving or are home later than planned.

Meanwhile, smart meters enable you to monitor your energy usage in real time, helping you to spot ways in which you can cut back, such as taking shorter showers or using your washing machine at a different time of day.

Smart LED lights can also be linked to mobile apps, so if you leave a light on in a room you are not using, you can turn it off through your smart phone, while smart plugs enable you to turn off appliances that are on standby remotely.

Triple glazed windows consist of three sheets of glass with two gaps in between them. These gaps are filled with air or an inert gas which stops heat being lost through the glass.

The additional pane of glass in triple-glazed windows generally makes them better at insulating your home compared with double-glazed ones.

The most energy efficient type of glass for triple glazing is known as low emissivity, or low-E, glass, which has a thin layer of metal oxide on one side of it to reflect heat back into your home, while still allowing sunlight through.

The size of the gap between the panes of glass also impacts the performance of triple glazing, with a gap of 16mm typically considered to be optimum, while having the gap filled with an inert gas, such as argon, xenon or krypton, is generally better than air.

The windows are also most efficient when the so-called pane spacers, which keep the panes of glass apart, contain little or no metal. These are often referred to as warm edge spaces.

If you are confused about how to select the most energy efficient windows for your home, the good news is that the British Fenestration Rating Council gives windows an energy rating on a scale of A++ to E, under which A++ is the most energy efficient.

The cost of a triple glazed window ranges from £500 to as much as £2,200, depending on the type,

According to glazing specialists Everest, triple glazing is 20-30% more efficient at keeping the heat in your home compared with double glazing.

If you live in a listed building or conservation area, you may need planning permission to put in triple glazing.

Installing solar panels enables you to generate your own renewable energy, reducing the amount you buy from a utility provider and even enabling you to make some money through selling energy to the grid.

A typical solar photovoltaic (PV) system consists of 10 panels, which take up around 20 sq m of roof space.

You'll also need an inverter to convert direct current (DC) energy generated by the panels into alternating current (AC) that household appliances run off.

But before going ahead, it is important to be sure that your property is suitable for solar panels. 

Ideally, you need an unshaded, south-facing roof. You can still install the panels if your roof faces east or west, but they will generate around 15% to 20% less energy.

Installing solar PV panels on a north-facing roof is not recommended.

You will also generate more energy if you live in a part of the country that gets a lot of sun, such as the south, and your roof has a good tilt.

Solar panels aren’t cheap, with a medium-sized system costing around £6,000 to install. You should also budget for lifetime maintenance costs of around £1,450.

The amount of money you save varies according to how much sun your roof gets but as a guide, a medium-sized system on a south-facing roof could save you £210 a year in energy bills and make you £160 a year through selling energy back to the grid.

If you're interested in going ahead, the Energy Saving Trust has a solar energy calculator that helps you estimate how much energy you are likely to be able to generate, based on your home’s location and roof size and pitch.

Solar PV panels are classed as permitted development, so you don’t automatically have to get planning permission to install them. 

That said, you may need permission under certain circumstances, such as if you live in a conservation area or a listed building, so it’s best to check. 

Are solar panels worth the money?

Ground source heat pumps work by transferring heat from the ground to radiators and underfloor heating in your home. They can also be used to heat water.

A loop of pipe, with a mixture of water and antifreeze inside it, is buried deep in your garden.

Heat from the ground is then absorbed by the fluid in the pipe, which then passes through a heat exchanger into a heat pump, which raises the temperature of the fluid and transfers that heat to water.

A ground source heat pump isn’t right for everyone. You'll need to have enough outdoor space to either dig trenches or drill vertical boreholes for the ground loop. 

And the chosen area will need to be away from trees and have road access for machinery.

You'll also need space inside your home for the indoor heat pump unit, which is typically the size of a large fridge.

As with gas central heating, ground source heat pumps use hot water to heat a home, so you'll need to have a hot water heating system with radiators and/or underfloor heating in place.

Ground source heat pumps are expensive to install, coming in at around £24,000 for a ground loop buried in trenches and £49,000 for a borehole.

The amount a ground source heat pump will save you on your fuel bills varies according to the system it is replacing. 

For a typical well-insulated three-bedroom semi-detached home savings range from £1,600 a year if it's replacing old electric storage heaters to £195 a year for a new gas boiler.

If you don’t have the space for a ground source heat pump, you may want to consider an air source one.

These transfer heat from outside air to water, which is then used to heat your home through radiators or underfloor heating, as well as to provide hot water.

There are two types of air source heat pumps: monobloc and split systems. 

In a monobloc system all of the components are in an outdoor unit, with just a hot water cylinder in your home.

Monobloc systems tend to be quicker and cheaper to install and take up less space inside than split systems. But the downside is they are slightly less energy efficient.

As the name suggests, split systems have units both indoors and outdoors.

As a result, they take up more space inside and are more expensive to install, but are also more energy efficient. That's because less heat is lost during the heat transfer process since it takes place indoors.

If you want to use either system to generate hot water, you will need a hot water cylinder to store the water, as air source heat pumps do not produce hot water on demand.

A downside of both monobloc and split systems is that they can be noisy, because they use large fans to move air across the heat exchange in the outdoors unit.

In normal conditions, the noise is similar to that of a fridge, but it does increase as the outside temperature falls and the system has to work harder. 

Air source heat pumps typically cost between £7,000 and £13,000 to install. 

Energy bill savings range from £1,500-a-year if you are replacing old electric storage heaters to £115-a-year for a new gas boiler, based on a well-insulated three-bedroom semi-detached home.