The cavity wall grant in Mayo
The SEAI cavity wall grant is the same in Mayo as everywhere: €1,800 for a detached house, €1,300 for a semi-D or end of terrace, €850 for a mid-terrace and €700 for an apartment, more on the higher rate. Mayo has the most detached houses of these ten counties, seven in ten, and the highest share of rated homes with an empty cavity.
Installers covering Castlebar, Ballina, Westport, Claremorris, Ballinrobe and Ballyhaunis. What Mayo homes get, the walls here and the next step.
Free, no obligation. One registered installer prices it, not five.
- 93%of Mayo homes built before 2011
- 70%are detached houses
- 9,955rated homes with an empty or part-filled cavity
- 2,118grant claim BERs in 2026 so far
Homes in Mayo that qualify
93% of Mayo's 51,996 households live in a home built before 2011, against 92% nationally (Census 2022): those are the homes old enough for the grant. 70% are detached, 17% semi-detached, 9% terraced and 5% apartments. With so many detached houses, the typical grant here is the €1,800 one.
- 93%built before 2011
- 70%detached
- 17%semi-detached
- 5%apartments
Check your cavity wall grant
Four quick taps. You see your grant as you go, then what the job typically costs after it, the BER and your next step. Your number is only asked for at the end, if you want a price.
A semi-detached built before 2011, no earlier wall grant: a €1,300 grant, and the job typically costs €1,585, so about €285 is left to pay.
How this is worked out
SEAI pays a fixed cavity wall grant for each house type, and a higher fixed amount to homeowners on certain welfare payments and to landlords with a HAP or RAS tenant. The typical cost is the median price of cavity wall insulation for your house type across thousands of grant-funded jobs, and the post-works BER is its median price less its own grant. Your installer prices your walls after a look: it's a guide to plan with, never a quote. SEAI decides every grant.
The walls in Mayo
Of 21,451 homes in Mayo built before 2011 that have a BER (leaving out BERs done for grant claims), 6.0% have an empty cavity and 40.4% a cavity that's only partly insulated, against 4.5% and 28.3% nationally. 23.1% have a filled cavity already. 14.4% have solid walls and 0.4% hollow block, which have no cavity to fill and need internal or external insulation instead.
Heat and weather in Mayo
61% of Mayo homes heat with oil and 3% with gas (Census 2022). Around Castlebar it's 2,028 heating degree days a year, the measure of how much heating a home needs, 13th coldest of the 26 counties (Met Éireann 1991 to 2020), close to the middle for the country.
Grant claims in Mayo
2,034 BERs in Mayo were done for SEAI grant claims in 2025, and 2,118 in 2026 up to late October, already more than all of last year. Every grant claim needs one, so it's a fair count of how many homes here are using the grants.
Requests from Castlebar, Ballina, Westport, Claremorris, Ballinrobe and Ballyhaunis go to one SEAI-registered installer who covers Mayo.
Your grant, by home and by route
The house type sets the grant. The route sets who applies and when you're paid.
Detached house€1,800, or €2,300 on the higher rate. The biggest grant, for the most wall.
Semi-D or end of terrace€1,300, or €1,700 on the higher rate, which covers the typical cost.
Mid-terrace house€850, or €1,100 on the higher rate. Two outside walls to fill.
Apartment€700, or €900 on the higher rate, and who applies in a block.
Landlords: HAP and RASThe higher rate for a let home with a HAP or RAS tenant, and the landlord deduction.
The higher rateMore for homeowners on certain welfare payments, without losing a place for free upgrades.
Free upgradesFully funded work for homes built before 2006 whose owners get certain payments.
One Stop Shop routeOne company applies, manages the work and takes the grant off your bill.Cavity Wall Insulation Grants guides & price breakdowns
Straight answers to what people ask most: itemised costs, specifications, planning or grants, and what to check before you book.
More guides & resources: The BER after cavity wall insulation · Had a wall grant before? The second wall measure · All guides & calculator hub · Technical & trade glossary · Frequently asked questions · All areas covered
Mayo questions
How much is the cavity wall grant in Mayo?
SEAI pays a fixed cavity wall insulation grant: €1,800 for a detached house, €1,300 for a semi-detached or end-of-terrace house, €850 for a mid-terrace house, €700 for an apartment. Homeowners on certain welfare payments, and landlords with a HAP or RAS tenant, get the higher rate: €2,300, €1,700, €1,100 and €900.
How many homes in Mayo could get the grant?
93% of Mayo households live in a home built before 2011 (Census 2022), and 46.4% of homes with a BER have an empty or part-filled cavity.
Is there free cavity wall insulation in Mayo?
Free upgrades are for homeowners who own and live in a home built and occupied before 2006 and get Fuel Allowance, Working Family Payment, One-Parent Family Payment, Domiciliary Care Allowance or Carer's Allowance (living with the person you care for), or Jobseeker's Allowance or Disability Allowance for over 6 months with a child under 7. An SEAI surveyor visits and recommends what's done, which can include insulation. There's a waiting list.
Do you cover all of Mayo?
Yes. Your request goes to one SEAI-registered installer who covers your county, including Castlebar, Ballina, Westport, Claremorris, Ballinrobe and Ballyhaunis.
Who will ring me?
One SEAI-registered installer who covers Mayo. Not a list. Nothing is agreed until you accept a written price.
Cavity Wall Insulation Grants across all 26 counties
Requests from all 26 counties go to one vetted local specialist who covers your county — from Dublin, Cork, Galway and Limerick to Kildare, Meath, Wicklow, Waterford and Donegal. Pick your county below for local prices, specifications and advice. Compare all areas covered →
Check your cavity wall grant
Four taps to your grant and what's left to pay, then one SEAI-registered installer who covers your county rings with a price.