House wall insulation and Cladding.
- Protect your home from heat loss.
- Save money on your heating bills.
- Lower your carbon footprint.
- Add value to your property.
Insulating your house walls could cut your heating costs considerably and make your home more comfortable whilst saving money from high energy bills.
If your home was built before the 1930s, its external walls are probably solid walls rather than cavity walls which are now common practice.
- Solid walls have no gap, so they can’t be filled with cavity wall insulation such as Rockwool or the new systems where companies add injection cavity insulation.
- Cavity walls are made of two layers with a small gap or ‘cavity’ between them.
Solid walls can be insulated through – either from the inside or the outside. This will cost more than insulating a standard cavity, but the savings on your heating bills will be bigger to.
Cost and savings
Typical installation costs* of wall insulation can vary as follows:
- External wall insulation: around £18,000 including your cladding.
- Internal wall insulation: around £10,500. (This will make your rooms smaller)
*Based on a typical 3-bedroom, semi-detached house in Great Britain
The costs we suggest for installing wall insulation via Greenoak Concept & Design is to, insulate your whole house in one go with airtec ybs bubble wrap, complete with new HardiePlank Cladding to provide your property with that extra curb appeal and adding value to your home.
If you’re looking to spend less, it is advisable to insulate a wall when you are having other building or decorating work done.
Internal insulation can be fitted when you’re planning to redecorate anyway, or to fit a new kitchen or bathroom. You can also spread the cost by tackling one room at a time.
External insulation will also cost less if you fit it when you’re having other work done to the outside. If you’re having a new roof, or painting the windows, or even having solar PV panels fitted, then you will probably have scaffolded up already, which can save a bit on the costs. If your walls need repointing or other repair work, it’s worth getting a quote for a complete refurbishment including insulation and have cladding – it will probably work out cheaper than doing the two things separately.
External wall insulation
External wall insulation involves fixing a layer of insulation material, in Greenoaks case this is Airtec ybs to the walls, then covering it with a special type of cladding, in our case this is HardiePlank Cladding.
The finish can be smooth or textured.
- External insulation:
Can be applied without disruption to the household does not reduce the floor area of your home.
- Will renew the appearance of outer walls.
- Will improve weatherproofing and sound resistance.
Fills cracks and gaps in the brickwork, which will reduce draughts.
- Increases the lifespan of your walls by protecting the brickwork.
- Reduces condensation on internal walls and can help prevent damp (but will not solve rising or penetration damp).
- Best installed at the same time as external refurbishment work to reduce the cost.
- May need planning permission – check with your local council.
- Requires good access to the outer walls.
Moisture movement and ventilation
In traditionally built properties with solid walls, water vapour can usually move quite freely through the building. This is partly because of the high levels of ventilation and draughts, but also because water vapour can travel through the bricks and stones that the walls are made of. When you insulate an older building, you will change the way that water vapour behaves in several ways:
- Adding wall insulation will usually cut down on draughts through the walls and round the windows.
- The insulation may create a barrier to vapour movement, depending on what materials are used.
- Adding insulation to the inside of a wall will make the wall colder. This means that any water vapour entering the wall from inside will get a lot colder and may condense inside the wall.
Whenever you fit solid wall insulation to a building you need to take account of water vapour to make sure that you don’t create new damp problems in the future. This may involve using “breathable” insulation materials that will allow the vapour to carry on permeating the walls, or it could involve creating a continuous vapour barrier to make sure no vapour can get into the walls from the inside. You will need an experienced specialist installer to develop a moisture control strategy that is specific to your building.
You should check with your installer that the installation is covered by an appropriate 10-year guarantee. They may be members of the HomePro guarantee scheme, or they may offer an independent insurance-backed guarantee. Greenoak Concept & Design are members
Internal wall insulation
Internal wall insulation is done by fitting rigid insulation boards to the wall, or by building a stud wall filled in with insulation material such as mineral wool fibre.
- 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 quite disruptive but can be done room by room.
- 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.
- Cannot be done before fixing any problems with penetrating or rising damp.