Short answer
Which wall insulation is right depends on your walls. Houses with a cavity usually get cavity wall insulation first: it is pumped in from outside in a day and is the cheapest. Solid-wall and older Dublin houses need external wall insulation (EWI, from €160/m²) or internal insulation (dry-lining). EWI keeps your room sizes and changes the outside look; internal insulation keeps the facade but loses some floor space. Phoenix Maco Ltd installs and certifies all three in Dublin.
Key points
- Cavity walls: cavity insulation is quick and low cost.
- Solid walls: choose external (EWI) or internal (dry-lining).
- EWI from €160/m²; no loss of room space.
- Internal insulation suits protected facades and single rooms.
- SEAI grants are available for all three on qualifying homes.
Cavity wall insulation
Most Irish houses built from the 1970s onwards have a cavity. Insulation beads are pumped into the cavity through small holes from outside, usually in a day, with no mess inside. A survey first checks the cavity is suitable.
External wall insulation (EWI)
Insulation boards are fixed outside and finished with render. It gives the biggest improvement for solid-wall houses, removes cold bridges and refreshes the outside look. Phoenix Maco EWI starts from €160/m². Front-facing changes may need planning permission in some areas, such as protected structures or conservation areas.
Internal wall insulation (dry-lining)
Insulated boards are fixed to the inside of external walls. It keeps the facade unchanged, which suits red-brick and protected houses, and can be done room by room. You lose some floor space and sockets, skirting and radiators need moving.
Quick comparison
- Cost: cavity lowest, internal mid, external highest per job.
- Disruption: cavity minimal, external outside only, internal inside rooms.
- Room size: cavity and external no change, internal smaller.
- Look: only external changes the outside.
Frequently asked questions
- Which is better, internal or external wall insulation?
- External usually performs better and keeps room sizes. Internal is best where the facade must stay the same or you want to work room by room.
- Does external wall insulation need planning permission?
- Usually not, but protected structures, conservation areas and some front facades may need it. Check with your council.
- How long does external wall insulation last?
- A well-installed, certified system typically lasts decades with basic maintenance.
- Does external wall insulation work?
- Yes. It greatly reduces heat loss through solid walls and improves comfort and BER.
- How much is external wall insulation per m²?
- Phoenix Maco EWI starts from €160/m² supply and install, before any SEAI grant.
- Do you do cavity wall insulation in Dublin?
- Yes. Phoenix Maco Ltd installs and certifies cavity, internal and external 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.