Insulating Your Home

Page last updated at 15 June 2017 at 12:07

Insulating Your Home House20heat20loss20perc M

There’s not much point heating the air in your home if it flies out through the roof, walls, and cracks. Insulation is a priority and any investment will pay for itself very quickly. 

The Council backed free loft and cavity wall insulation scheme, Insulate Hampshire, has come to an end. Free insulation is still available but not widely available.

Once you are keeping the heat in your house with better insulation and fewer draughts you will be able to turn your thermostat down to 18 or 19 degrees C and still feel warmer. Then top up the rooms you use with a wood burning stove or individual room heater. 

Wall Insulation 

35% of heat lost in an uninsulated home is through the walls but it is possible to insulate most types saving up to £140 per year. 

Cavity Wall InsulationCavitywall

The majority of homes in the Borough have been built post Victorian times and so will most likely have cavity walls. These have 2 rows of bricks with a cavity in between and can be identified, if the wall hasn't been rendered, by a regular full length brick pattern as shown in the picture. 

Before installation, surveyors from the installing company will visit your home to check you have a suitable cavity by inserting a camera. Standard cavities are insulated by injecting rock wall or polystyrene beads into them through a series of holes at regular intervals. They will fill the holes but if you have render on your house you will be responsible for any subsequent decoration required. 

Grants are not widely available.  

Solid Wall Insulation Solidwall

If you have a solid wall you will see a brick pattern of one brick / half brick as shown in the diagram. With no cavity to fill, the only way to insulate, is by adding a solid layer of insulation to the internal or external wall. Either way it will require substantial remedial work and may change the appearance of your home.

Internal insulation will result in a smaller room and may require refitting the skirting boards and carpet. Once fitted the wall will need to be plastered and decorated. 

External insulation will change the appearance of your house because it may require changes to the roof line, soffits and guttering and the finished wall will need rendering. You may need planning permission if you live in a conservation area. 

Solid wall insulation is costly but there are grants available to part of fully fund it. Contact the Energy Savings Advice Service on 0300 123 1234 who will be able to advise further. 

Hard-to-treat Cavity Walls

If your cavity wall isn't standard and can't be treated in the usual way it can be classed as hard-to-treat and the reason is one of the following:

  • A cavity wall in a building with three or more storeys.
  • The wall is in an exposed area and can't be treated with usual materials.
  • A partially filled cavity where solid insulation has been used but a gap remains.
  • Remedial work is required before the insulation is injected.
  • The cavity is less than 50mm wide.
  • The cavity is in homes of prefabricated concrete construction or metal frame cavity walls.
  • An uneven cavity formed in walls constructed of natural stone. 

These must be insulated using different techniques, often more expensive, but there are grants out there to help you. In many cases a report from a chartered surveyor will be required. Contact the Energy Savings Advice Service on 0300 123 1234 who will be able to advise further. 

Loft Insulation

Even if your loft is insulated, it probably needs topping up –the thicker the better. Current standards recommend 27cm (10 inches) and that means going above the height of your rafters. It is important not to squash the insulation so if you use your loft for storage you will need to get loft legs or stilts to raise the floor up. 

Insulating rolls are the most common type of insulation and can be laid by a confident DIYer fairly easily. Fill the gaps between the rafters and then lay another layer in the other direction across the top. Always refer to the manufacturer's instructions to ensure you are fitting it correctly and try not to leave any gaps between the rolls but as a minimum remember these points:

  • Always keep the loft well ventilated. Moisture will naturally rise in a house and collect in the loft. Fresh air circulates under the eves into the loft in order to ventilate the area and avoid damp problems. Be careful not to block the ventilation by leaving a gap at the eves. This can be done easily by pushing a loft vent between the roof line and the insulation.
  • Wiring should be kept above the insulation but don't stretch it.
  • Ceiling lights in the room below should be covered with a fire hood before insulation is laid on top.
  • Do not insulate under a water tank and ensure all pipework and the loft hatch are insulated.
  • Don't forget to insulate the loft hatch by sticking 10cm (4 inches) thick solid insulation on to the top of your hatch. 
  • Always wear a face mask while laying the insulation to prevent dust entering your lungs
  • Always seek further advice before comencing work

Grants are not widely available.  

Cold Calling and misleading leaflets

Please be wary of salespeople cold calling or leaflets that indicate you qualify for free insulation because in most cases this won't be true. What usually happens is when the surveyor comes round he explains that unfortunately you don't qualify and will have to pay to have the works done. 

We do encourage people to insulate their homes and these schemes may be run by reputable companies even if their salesperson's engagement tactics are a bit dubious. 

Please remember the following

  • The Council has not authorised any insulation companies to canvass on our behalf. If a salesperson indicates he works for or with the Council, ask for their id and ring us on 023 8068 8000 to confirm. They won't mind waiting if it is true.
  • Insulate Hampshire, the council backed insulation scheme has ended.
  • Whoever does the work, make sure they are registered with the Cavity Insulation Guarantee Agency (CIGA) or National Insulation Association (NIA). Even if the installing company ceases trading your insulation will be guaranteed for 25 years. 

Top Tips

Download our Top tips for Insulation & Draught-proofing.


To find out more, contact Giles Gooding on 023 8068 8274, email, Twitter @EcoEastleigh