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 Mayo?

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 Mayo 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 Mayo

75 companies on the SEAI register are based in or serve Mayo 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 Mayo

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

Churchfield Home ServicesOne Stop Shop
Attic insulationCavity wall insulationExternal wall insulationHeat pumpHeating controlsInternal wall insulationSolar hot waterSolar panelWindow and door
Nationwide · SEAI no. 10253 · Website
Based in Mayo.
Clar ICH Ltd
Attic insulationCavity wall insulationInternal wall insulation
Nationwide · SEAI no. 12879
Based in Mayo.
Damien Ryan Contracts Ltd
Attic insulationCavity wall insulationExternal wall insulationInternal wall insulation
Based in Mayo · serves Dublin, Leinster, Munster and Connacht · SEAI no. 14637
Based in Mayo.
E.C.S.C Insulation Services Ltd
Attic insulationCavity wall insulationInternal wall insulation
Based in Mayo · serves Connacht · SEAI no. 17934
Based in Mayo.
Eamonn Finn
Attic insulationCavity wall insulationInternal wall insulation
Based in Mayo · serves Dublin, Leinster, Connacht and Ulster · SEAI no. 18329
Based in Mayo.
Holmes Insulation LTD
Attic insulationCavity wall insulationInternal wall insulationWindow and door
Based in Mayo · serves Connacht · SEAI no. 10523
Based in Mayo.
Moran Retrofit Solutions
Attic insulationCavity wall insulationExternal wall insulation
Based in Mayo · serves Dublin, Leinster, Munster and Connacht · SEAI no. 17912
Based in Mayo.
Noel Holmes Construction Ltd.
Attic insulationCavity wall insulation
Based in Mayo · serves Connacht · SEAI no. 10366
Based in Mayo.
Ruane Insulation Ltd T/A Better Energy Solutions
Attic insulationCavity wall insulationInternal wall insulation
Based in Mayo · serves Connacht · SEAI no. 16390
Based in Mayo.
Superior Insulations Ltd
Attic insulationCavity wall insulationExternal wall insulationInternal wall insulation
Nationwide · SEAI no. 15150
Based in Mayo.
Walter Moran Insulation
Attic insulationCavity wall insulationExternal wall insulationInternal wall insulation
Based in Mayo · serves Connacht · SEAI no. 10082
Based in Mayo.

Also cover Mayo from elsewhere (64)

These told SEAI they cover the province Mayo 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.

Ashgrove Engineering Ltd T/A Ashgrove Renewables (OSS) · Bayview Contracts Ltd (OSS) · Bord Gais Energy Ltd (OSS) · Breffni Insulation Ltd (OSS) · Cooper Insulation Ltd. (OSS) · Electric Ireland Superhomes (OSS) · Energyfix (OSS) · Envirobead Ltd. (OSS) · Greenwatt Ltd (OSS) · House 2 Home Retrofit Ltd (OSS) · Kingdom Installation Ltd (OSS) · Kingspan Insulation Ltd (OSS) · Kore Retrofit 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 · Absolute Insulation Ltd · AC Insulation · Adrian Maguire T/A Abbey Insulation · All In Insulation · Alpha Insulation Ltd T/A Western Insulation · Anthony Coughlan Heating & Plumbing TA C&S Construction Services · Ardvark Insulation Ltd · Bio Insulate Ltd · Brusna Energy Solutions Ltd · C.D.M. Contracts Ltd · Corrib View Construction Ltd · Derchil Limited t/a CosiHomes · Eco Home Insulation · Ecotec Insulation Ltd · Ecotech Contracts IRI Ltd · Ecowise Insulation Ltd · Evertherm Ltd T/A Annalee Energy Ltd · Fagan Crossmolina Limited · Fahy Insulations Ltd · Finlay EcoFit Tullamore Ltd · Gallen Insulation Ltd · Harrington Insulations Limited · Innovate Insulation Ltd · Instant Eco Homes Ltd · Jacob Insulation Limited · John Doohan and Company Ltd · Kelly Insulation Heating & Plumbing · Kingscourt Insulation Ltd · Leitrim Warmer Homes CLG · McCormack Insulation · McInerney and Keane Insulation · Metro Insulation Ltd · Midland Warmer Homes Company Limited · National Retrofit & Construction Services Ltd · OCI Insulation · OG Insulation Limited · PNA insulation Ltd T/A O'Loghlen Insulation Ltd · Premier Insulations · Ryan Spray Foam · Spreadwell Construction Ltd · Sustainable Warmth Ltd · Thermowise Insulations Limited · Tirconaill Contracts Ltd T/A Mc Taggart Insulation · Warm 'n Cosy Homes Limited · West Coast Insulations Ltd

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 Mayo 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 Mayo

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 Mayo?: 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 Mayo 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 Mayo

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.