Insulation

As much as 65% of the heat you pay for may be being wasted as a result of an un-insulated home. Installing insulation will reduce this heat loss as well as saving money and cutting down on CO₂ emissions.

Loft

As much as a quarter of your heating costs could be escaping through the roof without loft insulation. Loft insulation is a very efficient way to reduce heating bills and should be effective for around 40 years.

Simply by insulating your loft to the recommended depth of 270mm, you can save wasted energy and money. If you currently have no insulation, you could save between £135 – £250 a year on your fuel bills depending on your house type and reduce carbon emissions by 550kg-1000kg.

If your home has an accessible loft with no damp or condensation problems, it should be a good candidate for loft insulation. Installers tend to use mineral wool insulation and laying this is usually straightforward for a professional.

You can even do it yourself! Remember to wear a facemask, goggles and protective clothing if you do it yourself and leave sufficient gaps around the eaves to avoid condensation.

For lofts with difficult access, a loose, fire-retardant insulation material can be blown into the loft using specialist equipment. This is a job for a professional installer and can take a few hours depending on the size of the loft.

Tank and Pipes

Hot Water Tank Insulation

Insulating hot water tanks and pipes will help keep your water hot for that nice long bath after a hard day’s work.

Fitting your hot water cylinder with an insulating jacket will save you £20 a year in heating costs and 150kg of carbon dioxide emissions. A jacket costs around £15 and can be found in any good DIY store and are cheap and easy to fit.

Not all home insulation work has to be carried out by a professional. It may work out cheaper to do the smaller jobs yourself with materials from your local DIY store.

Pipe Insulation

Pipe insulation consists of a foam tube that covers the exposed pipes between your hot water cylinder and boiler, reducing the amount of heat lost and, therefore, keeping your water hotter for longer.

It’s usually as simple as choosing the correct size from a DIY store and then slipping it around the pipes.

Walls

Does your home have cavity walls?

Un-insulated cavity walls cost you money. Up to 33 per cent of the heat produced in your home is lost through the walls.

The good news is that cavity wall insulation is quick, clean and relatively inexpensive and it could save you between £85 – £280 a year on your fuel bills, depending on your house type. It is the most cost-effective way of significantly reducing your energy costs. It could also reduce carbon emissions by 335kg-1150kgs per year.

It will create an even temperature in your home, help prevent condensation on the walls and ceilings and can also reduce the amount of heat building up inside your home during summer hot spells.

It will normally cost around £345 to £600 to install depending on house type and will pay for itself in approximately 5 years.

What is cavity wall insulation?

Cavity wall insulation is injected into the cavity between the inner and outer leaves of brickwork that make up the external wall of your property. An installer will do this from the outside of your property. There are a variety of different insulating materials although the material used will most likely be mineral wool or polystyrene beads, but they all work in the same way: by combining with the still captive air, the insulation acts as a barrier to heat loss. The installer will take roughly between two to three hours for a three-bedroom semi-detached house. The work will be guaranteed for 25 years by the Cavity Insulation Guarantee Agency (CIGA).

How do I know if my home is suitable?

First of all, check the age of your house. In most houses built after the 1920s, the external walls are made of two layers with a small air gap or ‘cavity’ between them. This means they are ‘cavity walls’ and the gap between them can be filled with insulating material to stop the warmth escaping to the outside.

Looking at the brick pattern of your outside walls can also help to identify cavity walls, as this will usually differ from solid walls.

Generally speaking, your home will be suitable for cavity wall insulation if:

the external walls are unfilled cavity walls
the masonry and/or brick work is in good condition
your cavity is at least 35mm wide (or 50mm for some forms of insulation)
the walls are not exposed to driving rain
your house is not at risk of flooding

Houses built since the 1990s are likely to have insulated cavities.

In all cases if you are thinking about cavity wall insulation, always check with a registered installer who will assess whether your home is suitable.

Your installer should be a member of one of these organisations:

Check whether the installer is signed up to a code of professional practice and that the installation is guaranteed for 25 years by CIGA, or through an independent insurance-backed guarantee.

Does your home have solid walls?

If you live in a home with uninsulated solid walls, 45% of your heat is escaping through the walls which is costing you money. Insulating the walls will dramatically prevent heat loss in the winter and greatly reduce your heating bills.

Solid walls can be insulated either from the outside (external) or the inside (internal).

Solid walls are mainly made of brick or stone and are found in most houses built before 1919.

The easiest way to tell is from the pattern of the bricks on the outside of your house. If your home has solid walls, the bricks will tend to be placed head-on and lengthways in an alternating pattern like this.

If the brickwork has been covered, you may be able to tell a solid wall by measuring its thickness. Go to a window or door on one of your outer walls and take a measurement there.

if a brick wall is more than 260mm thick then it is probably a cavity wall
a narrower wall is probably a solid wall. Stone walls may be thicker still but are usually solid.

If you live in a house that has a non-traditional construction such as a concrete, steel or timber-framed building, you will need a specialist installer with experience in insulating your building type to advise you on your options.

External wall insulation

External Wall Insulation (EWI) involves fixing a layer of insulation material to the wall, then covering it with a special type of render or cladding. The finish is usually a textured render, pebbledash or sometimes a brick slip or a brick effect render finish could be used.

External solid wall insulation requires a specialist approved installer. To find one in your area, visit National Insulation Association website.

Advantages of External Wall Insulation

can be applied with minimal disruption to the household and its occupants
no internal access is required
does not reduce the floor area (living space) of the property
improves the appearance of the property – potentially increasing the property’s value
improves weatherproofing and sound resistance
can make the building more airtight, reducing drafts and heat loss
increases the life of the existing property by protecting the existing substrate from the weather
reduces condensation on internal walls and can help prevent damp (but will not solve rising or penetration damp)

* figures provided by Energy Saving Trust. Costs may vary significantly depending on level of work required.

	Detached	Semi-detached	Mid terrace	Bungalow	Flat
Fuel bill savings (£/year)	£355	£225	£145	£150	£105
Carbon dioxide savings (kgCO₂/year)	1,540 kg	930 kg	590 kg	620 kg	425 kg

Typical installation costs

External wall insulation: £10,000
Internal wall insulation: £8,000

Internal Wall Insulation

Internal Wall Insulation (IWI) is applied to the internal walls of a building. It is done by fitting rigid boards to the wall, or by building a stud wall filled in with insulation material such as mineral wool fibre.

Rigid insulation boards come in varying thicknesses depending on the price. The cheaper ones are thicker so you will lose some floor space for each wall. The highest energy savings are made with the rigid insulation boards.
Flexible insulation sheets are cheaper, come in rolls and hung like wallpaper. These are thinner so take less space but are not as efficient.

Key points:

is generally cheaper to install than external wall insulation
will slightly reduce the floor area of any rooms in which it is applied (the thickness of the insulation is around 100mm)
can be disruptive but can be done on a room by room basis
requires skirting boards, door frames and external fittings to be removed and reattached
can make it hard to fix heavy items to inside walls – although special fixings are available
needs any problems with penetrating or rising damp to be fixed first

External Wall Insulation Aftercare

Using ladders

When using ladders, the ladders should not be directly rested on the render coating as this may cause damage even if protective ends are fitted to the ladders. If ladders are used, the system designer recommends using a load spreading plate to distribute the weight over the rending coating.

New fittings

Should a new fixing point be required after the application of the system, the system designer recommends the following:

For new fittings less than 5kg in weight use SPS Envirowall spiral plugs (ESPDU). The fixings can be installed using hand tools, but you may need to drill a 3mm pilot hole first. A mastic bead should be used on the final thread of the spiral screw to seal the fixing. A traditional external grade screw can then be used for fixing the new external fixture back to the spiral screw head.
For new fittings greater than 5kg in weight, the system designer recommends the use of Fischer Thermax fixings that are fixed back through the insulation to the main building substrate. These are purpose-built fixings that are designed for cladding systems and have a high resistance to flexing.

These can be purchased direct from the system designer SPS Envirowall.

T – 0845 094 4828
E – info@spsenvirowall.co.uk

Plants and shrubs

It is advisable to avoid planting climbing plants such as Ivy close to the wall as these can be very destructive over time to the render surface.

Mastic seals

As part of the installation, our contractor has applied mastic sealing around windows and doors. Mastic sealing does not have the same life expectancy as the insulation system and should be renewed periodically where appropriate.

For more information on maintenance of the system click here to read SPS Envirowall Maintenance and Repair Manual.

Draught proofing

Here’s a simple test – hold the palm of your hand up against the windows in your home. If you feel cold air coming through, warm air is escaping. In fact, in a typical home 20 per cent of all heat loss is through ventilation and draughts.

Draught proofing is an easy, cost-effective way to reduce heating bills and carbon emissions.

The most common draught-zones

Windows: Use foam, metal or plastic draught strips, or brush seals for sash windows. Temporary secondary glazing is another option.

Exterior doors: Fit brush or hinged-flap draught excluders along the bottom of the doors. If you don’t have a keyhole cover, buy a purpose-made cover that drops a metal disc over the keyhole. Use a letterbox flap or brush but remember to measure your letterbox before you buy.

Interior doors: Cut draughts with ‘snake’ draught excluders, brushes or similar strips of material but remember to leave kitchen and bathroom as ventilation is important.

Unused chimneys:

fit a cap over the chimney pot – this might be better done by a professional
buy a chimney draught excluder – this will help stop draughts and heat loss through the chimney, and are usually fitted inside the chimney or around the fireplace

Remember to remove the draught-proofing if you decide to light a fire.

Around pipework: Apply silicone fillers or expanding foam as appropriate.

Floorboards and skirting boards: Fill the gaps with flexible fillers, clear or brown silicone mastic, decorators’ caulk or similar products.

Cracks in walls: Use cement or a hard-setting decorators’ wall-filler.

Redundant extractor fan outlets: Old fan outlets may need to be filled with bricks or concrete blocks and sealed from both the inside and outside.

Loft hatches: Use strips of draught excluding material fitted around the edges of the frame, and don’t forget to insulate the hatch itself.

Lighting and electrical fittings: Plug the gaps around the fittings with wall-filler.

Caution: Adequate ventilation is as important as draught proofing – and essential.

Floor Insulation

Rooms can sometimes feel cold due to strong drafts rising up from gaps between the floorboards or between the skirting board and the floor.

This is easily resolved by investing in a regular tube sealant, such as silicon and filling the gaps. Even this will save you around £25 a year in heating bills.

Another way of reducing draughty floors is to insulate underneath the floorboards on the ground floor. This can be done by laying mineral wool insulation supported by netting between the joists. As well as making the room feel warmer, it will save you around £40 a year for an approximate outlay of around £100.

Caution: Don’t block under-floor airbricks in your outside walls. Floorboards will rot without adequate ventilation.

Rugs and carpets on the floor will also help your feet feel warmer – which might mean you don’t feel the need to put the heating on as much.

Some jobs may require a professional or you may not feel able to do the job yourself. Find an installer who is a member of the National Insulation Association.

Windows

Double Glazing

Poorly insulated window frames and single glazed windows account for up to 20 per cent of heat loss in the average home.

Double glazing creates an insulating barrier by trapping air between two panes of glass and reduces heat loss, noise and condensation. Replacing all single-glazed windows with B-rated double glazing could save you around £165 per year on your energy bills.

There are a variety of frame materials to choose from such as wooden, uPVC, aluminium or steel or composite frames.

They also vary, depending on:

how well they stop heat from passing through the window
how much sunlight travels through the glass
how little air can leak in or out around the window

Always look for the Energy Saving Recommended logo when choosing your windows as the whole window is assessed on a rating of A-G by the British Fenestration Rating Council.

If you can’t afford to replace all your windows at once, start with the rooms that you heat the most. Alternatively, think about secondary glazing which costs less to install but could still save you money by cutting heat loss and draughts.

Secondary Glazing

Double glazing may not always be an option for everyone, however, it is still possible to cut out the draughts and reduce heat loss through windows using various forms of secondary glazing. Some can be bought from your local hardware store and fitted yourself, others are more specialist. Some of the secondary-glazing options listed below are not allowed in listed buildings, so check first.

Transparent film secondary glazing

The simplest and cheapest form of secondary glazing is thin transparent plastic film which you install yourself using strips of double-sided sticky tape around the frame of the window. The material looks like ‘cling-film’, but if fitted properly it is wrinkle-free and almost invisible.

Temporary secondary glazing

Next up, in terms of expense, complexity and permanence are the systems in which a sheet of rigid and transparent material like clear acrylic plastic is fitted to the window frame, in such a way that it can be put up or taken down as the season requires. Some systems use magnet strips to attach the secondary glazing to the frame, others a Velcro-like material. A particularly popular method is ‘clip and stick’ where uPVC edging is used to clip the panel in place over the window frame. These types of glazing also help reduce noise.

Semi-permanent secondary glazing

Some of the more expensive types of secondary glazing are semi-permanent and are fixed either by screwing them into place or using a strong adhesive or sealant. They can be made of heavy materials like glass. On wider windows they can slide open on tracks to allow the windows to open as normal. These types are not generally suitable for DIY. Sash windows are notorious for letting in cold air. You can get clear, light-weight acrylic panels to fit over the glazed frames, but these don’t cover the many gaps on the sides, top and bottom that make sash frames particularly draughty.