Do I have to use one of these companies to get the grant?

Yes. SEAI only pays a grant on work done by a company on its register, and the company claims it on your behalf. Work done by anyone else is not covered, however good it is.

How many quotes should I get in Cork?

Three, from companies registered for the same job, and ask each for a written breakdown. Quotes for the same house often differ by thousands because they include different work, not because one is dearer.

Is this list in any order of merit?

No. Companies based in Cork come first, then the ones that travel to it, then One Stop Shops, then alphabetical. Being on the register means the paperwork is in order, not that the work is good.

Cavity wall insulation installers in Cork

86 companies on the SEAI register are based in or serve Cork for cavity wall insulation (register as of 8 September 2026).

Insulation boards fixed to the outside walls of a terrace mid-job, meter boxes hanging clear of the wall. — Garrick Close, Kingston upon Hull: bungalow renovations, November 2023 · Hullian111 · CC BY-SA 4.0 · Photo credits

Based in Cork

12 of them. Sorted by what they are registered for, then by name — this is not an order of merit.

Ashgrove Engineering Ltd T/A Ashgrove RenewablesOne Stop Shop
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterSolar panelWindow and door
Nationwide · SEAI no. 12010 · Website
Based in Cork.
Envirobead Ltd.One Stop Shop
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterWindow and door
Nationwide · SEAI no. 10218 · Website
Based in Cork.
Kilgobbin Castle Holdings Ltd t/a InsulexOne Stop Shop
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterWindow and door
Based in Cork · serves Dublin and Munster · SEAI no. 10496 · Website
Based in Cork.
Munster External Wall Insulation T/A SE SystemsOne Stop Shop
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterSolar panelWindow and door
Based in Cork · serves Dublin and Munster · SEAI no. 14825 · Website
Based in Cork.
Anthony Coughlan Heating & Plumbing TA C&S Construction Services
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterWindow and door
Nationwide · SEAI no. 10791
Based in Cork.
C & W Insulations
Attic insulationCavity wall insulationExternal wall insulation
Based in Cork · serves Leinster and Munster · SEAI no. 10016
Based in Cork.
Connolly Insulation
Attic insulationCavity wall insulation
Based in Cork · serves Munster · SEAI no. 11749
Based in Cork.
Corkery Alu-Cast Enterprises Ltd
Attic insulationCavity wall insulation
Based in Cork · serves Dublin and Munster · SEAI no. 15279
Based in Cork.
IRD Duhallow
Attic insulationCavity wall insulationInternal wall insulation
Based in Cork · serves Munster · SEAI no. 16261
Based in Cork.
J.D. Buckley Construction Ltd
Attic insulationCavity wall insulationExternal wall insulationInternal wall insulationWindow and door
Based in Cork · serves Munster · SEAI no. 10095
Based in Cork.
OS Insulate Ltd
Attic insulationCavity wall insulationExternal wall insulationInternal wall insulation
Based in Cork · serves Munster · SEAI no. 15563
Based in Cork.
Solastech Insulation Ltd
Attic insulationCavity wall insulation
Based in Cork · serves Munster · SEAI no. 10797
Based in Cork.

Also cover Cork from elsewhere (74)

These told SEAI they cover the province Cork is in, or listed it among the counties they serve. Ask how far they travel before you go any further. Names only here; each one's full register row is on its own county page. OSS = One Stop Shop.

Bayview Contracts Ltd (OSS) · Bord Gais Energy Ltd (OSS) · Breffni Insulation Ltd (OSS) · CBM Munster Construction T/A Home Energy Retrofits (OSS) · Churchfield Home Services (OSS) · Electric Ireland Superhomes (OSS) · Energlaze Home Energy Upgrades (OSS) · Energywise Ireland (OSS) · Greenwatt Ltd (OSS) · House 2 Home Retrofit Ltd (OSS) · Kingdom Installation Ltd (OSS) · Kingspan Insulation Ltd (OSS) · Kore Retrofit Ltd (OSS) · Leetherm Project Management Ltd (OSS) · Moston Construction Ltd (OSS) · OHK Energy LTD (OSS) · Retrofit Design Ltd (OSS) · Retrofit Energy Ireland (OSS) · SSE Airtricity Energy Services Ltd (OSS) · AB Teague Enterprises Ltd · All In Insulation · Alpha Insulation Ltd T/A Western Insulation · Ardvark Insulation Ltd · Carlow Insulation Solutions · CK Energy Management Solutions (EMS) Ltd t/a ENCON · Clar ICH Ltd · Corrib View Construction Ltd · Cosyfill Insulation · Damien Ryan Contracts Ltd · Derchil Limited t/a CosiHomes · Dungarvan External Insulation Ltd · Dungarvan Insulation Ltd · Eco Home Insulation · Ecosy Better Homes Ltd · Ecotec Insulation Ltd · Ecotech Contracts IRI Ltd · Ecowise Insulation Ltd · Eirgreen · Evertherm Ltd T/A Annalee Energy Ltd · Fagan Crossmolina Limited · Finlay EcoFit Tullamore Ltd · Five Counties Home Insulation Limited · Harrington Insulations Limited · Home Works Insulation · Innovate Insulation Ltd · Instant Eco Homes Ltd · Jacob Insulation Limited · John Taylor Construction Ltd · Kelly Insulation Heating & Plumbing · Kingscourt Insulation Ltd · Leetherm Insulation Ltd. · Leitrim Warmer Homes CLG · MAK Building Services Ltd · McCormack Insulation · McInerney and Keane Insulation · Metro Insulation Ltd · Michael Ormond Ltd · Midland Warmer Homes Company Limited · Moran Retrofit Solutions · National Retrofit & Construction Services Ltd · O Leary Insulation · OG Insulation Limited · PNA insulation Ltd T/A O'Loghlen Insulation Ltd · Premier Insulations · Quilter Insulation · Ryan Spray Foam · Sheehy Insulation Ltd · South East Insulations · Spreadwell Construction Ltd · Stone Arches LTD T/A Waterford Insulation · Superior Insulations Ltd · Sustainable Warmth Ltd · Thermowise Insulations Limited · Tirconaill Contracts Ltd T/A Mc Taggart Insulation

What it costs, and what the grant pays

The grant for a semi-detached house is €1,300. SEAI recorded a middle price of €1,550 for this work last year, which leaves about €250 for you to pay. These are national figures, not Cork ones — SEAI does not publish prices by county.

What it costs on a home like yours, and what you are left paying

Before you sign

Wait for your grant approval email before any work starts. SEAI does not pay for work that began before it was approved.
Get at least three quotes, and check each one covers the same job — the cheapest quote is often the one that leaves something out.
Check the company is on the register on the day you sign. Companies join and leave it, and this page is a copy taken on one day.
Get it in writing: what is being done, what it costs, when it starts and when it is finished.

How the application works

Ask up to five of them

Fill in one form, tick who you want to hear from, and we pass your details to those companies and nobody else. It costs nothing and you are under no obligation.

Get cavity wall insulation quotes in Cork

Common questions

Do I have to use one of these companies to get the grant?: Yes. SEAI only pays a grant on work done by a company on its register, and the company claims it on your behalf. Work done by anyone else is not covered, however good it is.
How many quotes should I get in Cork?: Three, from companies registered for the same job, and ask each for a written breakdown. Quotes for the same house often differ by thousands because they include different work, not because one is dearer.
Is this list in any order of merit?: No. Companies based in Cork come first, then the ones that travel to it, then One Stop Shops, then alphabetical. Being on the register means the paperwork is in order, not that the work is good.

Other work in Cork

Listed on SEAI’s public registers on 8 September 2026. Being registered is not an endorsement by SEAI or by us. Check the current register on seai.ie before you sign anything. Not affiliated with SEAI.