Help & Support

What you need to know about wall insulation

You can reduce your heating bill by up to 30%**. Insulating your walls will deliver long-term savings and improve the comfort of your home. Carrying out this work on your home may also qualify for an SEAI grant and our Energy Efficiency Incentive.

There are three main methods of wall insulation. An insulation specialist can advise you on what method is most suitable for your home.

Cavity Wall insulation

A cavity wall usually consists of two leafs of bricks or blocks with a space between them.

If you have cavity walls, insulation can be injected to fill the cavity. Houses with solid walls or hollow block walls cannot be insulated with cavity fill insulation. Consider using internal or external insulation instead.

The typical cost of cavity wall insulation will vary and there is a potential SEAI grant of up to €250**.

Internal insulation

This is a cost-efficient method of external wall insulation. Also known as dry-lining, it involves fixing insulation to the inner surfaces of the external walls.

All work is finished with skimmed plasterboard slab to a professional standard.

The typical cost of full internal wall insulation will vary and there is a potential SEAI grant of up to €1,350**.

External insulation

As the name suggests, this involves fixing an insulating material to the outer surface of the walls of your house. It’s more expensive but highly effective.

Insulation comes in a wide range of finishes and colours. And this means you can improve the look of your home as well as making your home more energy efficient.

The typical cost of full external wall insulation will vary and there is a potential SEAI grant of up to €2,700**. For example, if you have a small, mid-terraced house, the grant could cover the total cost of your work. Please note that in some cases there may be an additional cost for moving services, such as phone or electricity cables, going into the house.

**Source SEAI. Savings and losses are calculated by SEAI. Grants are subject to BER. For full details on SEAI grants visit

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