Short answer
Cavity wall insulation is the cheapest way to insulate a house with a cavity wall. Insulation beads are pumped into the cavity through small holes from outside, usually in one day, with no mess inside. The price depends on wall area, access and the cavity width, and SEAI offers a cavity wall insulation grant for qualifying homes when you get approval before work starts. Phoenix Maco Ltd surveys, installs and certifies cavity wall insulation in Dublin.
Key points
- Usually done in a day from outside.
- Price depends on wall area, access and cavity width.
- A survey first checks the cavity is suitable.
- SEAI grant available for qualifying homes; apply first.
- Certified on completion.
How cavity wall insulation works
We drill small holes in the mortar joints, pump bonded insulation beads into the cavity until it is full, and fill the holes to match. Inside the house nothing changes.
What changes the cost
- Total wall area and house type.
- Cavity width and condition.
- Access: extensions, conservatories, high gables.
- Vents to keep clear or sleeve.
SEAI cavity wall insulation grant
SEAI offers a cavity wall grant for qualifying homes. You must apply and be approved before the work starts, and use an SEAI-registered contractor. Check current amounts on seai.ie.
Is my house suitable?
Most Irish houses built from the 1970s onwards have a cavity. Solid-wall houses need external or internal insulation instead.
Frequently asked questions
- How much does cavity wall insulation cost in Ireland?
- It depends on wall area, access and the cavity. It is the lowest-cost wall insulation. Get a written quote after a survey.
- Is there a grant for cavity wall insulation?
- Yes, SEAI offers a cavity wall insulation grant for qualifying homes. Apply before work starts.
- How long does cavity wall insulation take?
- Most houses are done in one day.
- Can cavity wall insulation cause damp?
- Not when the cavity is surveyed first and installed correctly. Unsuitable or damaged walls are flagged at survey.
- Do you do cavity wall insulation in Dublin?
- Yes. Phoenix Maco Ltd installs and certifies cavity wall insulation in Dublin. Call or WhatsApp 083 874 5535.
Official Irish sources
Rules, grant values and rates change. This article is general information, not professional advice — confirm the current position with the relevant body or your own architect, engineer or surveyor.