Retrofitting means upgrading an existing home to make it warmer, cheaper to heat and more energy-efficient. It covers everything from insulating your attic and walls to replacing your boiler with a heat pump, upgrading windows and installing solar panels.
Ireland has committed to retrofitting 500,000 homes to a BER of B2 or better by 2030. As of the end of 2025, approximately 55,893 homes had reached that standard – meaning 75,000 homes per year need to be upgraded from 2026 to 2030 to hit the target.
With the National Residential Retrofit Plan 2026 bringing the biggest package of grants yet – including up to €12,500 for heat pumps, new window and door grants, and increased insulation support – there has genuinely never been a better time to retrofit your home.
🏠 Why Retrofit Your Home?
Ireland’s housing stock is among the least energy-efficient in Europe. Many homes built before 2005 have poor insulation, draughty windows and oil or gas boilers that waste huge amounts of energy. Retrofitting addresses all of these problems.
The benefits are immediate and significant:
🌿 Lower energy bills – a properly retrofitted home can cut heating costs by 40-60%. Moving from a D rating to a B2 can save €1,000 to €2,000 per year in energy costs alone.
🌿 A warmer, more comfortable home – no more cold spots, draughts or damp. A retrofitted home holds heat evenly and stays comfortable with less energy input.
🌿 Higher property value – ESRI research shows each BER letter improvement adds 2-3% to the sale price. On a €300,000 home, moving from D to B could add €12,000 to €18,000.
🌿 Better health – cold, damp homes are linked to respiratory problems, mould-related illness and poor mental health. Retrofitting eliminates these issues.
🌿 Lower carbon emissions – residential buildings account for a significant share of Ireland’s greenhouse gas emissions. Retrofitting directly reduces your home’s carbon footprint.
🌿 Green mortgage access – most Irish lenders now offer preferential interest rates for homes with a BER of B3 or better.
🔧 What Does a Retrofit Include?
A full retrofit (or “deep retrofit”) typically involves multiple upgrades carried out together to bring a home from a poor BER (D, E, F or G) up to B2 or better. The main elements are:
🔹 Insulation
This is the foundation of any retrofit – the “fabric first” approach. Without proper insulation, any heating system will waste energy.
🌿 Attic insulation – a house loses 20-30% of heat through the roof. Adding 300-400mm of insulation is one of the cheapest and most effective upgrades.
🌿 Cavity wall insulation – filling the gap between inner and outer walls with insulation material. Relatively quick and affordable.
🌿 External wall insulation – wrapping the outside of the house in insulation boards and a new render finish. More expensive but dramatically effective, especially on solid-walled homes.
🌿 Internal wall insulation – applying insulation boards to inside walls. An alternative where external insulation is not practical.
🌿 Floor insulation – reduces heat loss through ground floors, particularly in older homes with suspended timber floors.
🔹 Windows and Doors
Upgrading from single glazing or old double glazing to modern energy-efficient windows and doors reduces heat loss, eliminates draughts and improves acoustic insulation. From March 2026, SEAI offers standalone grants for windows and doors for the first time – you no longer need to be doing a full deep retrofit to access this support.
The new windows must meet a U-value of 1.4 W/m²K or better. Your home also needs to meet a minimum fabric standard before qualifying – either a Heat Loss Indicator of 2.3 or better, or attic and walls rated “Good” or “Very Good” on your BER Advisory Report. If your home does not meet this standard, you can upgrade your insulation first (claiming separate grants) and then apply for the windows and doors grant.
Grant amounts for windows vary by dwelling type:
🌿 Detached house: up to €4,000
🌿 Semi-detached or end-terrace: up to €3,000
🌿 Mid-terrace: up to €1,800
🌿 Apartment: up to €1,500
For doors, SEAI offers up to €800 per external door, to a maximum of two doors (€1,600 total).
The typical cost of replacing all windows and doors in a 4-bed semi is around €18,000, falling to around €13,500 for a 3-bed terrace. The grant will not cover the full cost, but it takes a significant chunk off the bill – especially when combined with insulation grants.
🔹 Heating System
Replacing an old oil or gas boiler with a heat pump is the single biggest change you can make to your heating costs and carbon emissions. Heat pumps operate at 300-500% efficiency compared to around 90% for a modern boiler. (There is no grant for a like-for-like boiler replacement – the funding all points to heat pumps.) The SEAI grant of up to €12,500 from February 2026 covers the heat pump, central heating upgrades and a renewable heat bonus.
🔹 Biomass and Solid Fuel Considerations
Some homeowners – particularly in rural areas – ask about biomass boilers (wood pellet or log gasification) as an alternative to heat pumps. While biomass can be a viable option in certain situations, there are important things to know.
SEAI does not offer individual grants for biomass boilers under the Better Energy Homes scheme. Biomass may be supported through the One Stop Shop route as part of a deep retrofit where a heat pump is not suitable, but this is assessed on a case-by-case basis.
If your home currently runs on solid fuel (coal, peat, wood), be aware that the Renewable Heat Bonus of €4,000 is available when switching to a heat pump, and the Warmer Homes Scheme no longer installs fossil fuel boilers as of January 2025. The direction of travel is clearly towards electrification through heat pumps, and the grant system reflects this.
🔹 Ventilation
A well-insulated home needs proper ventilation to prevent condensation and maintain indoor air quality. Demand-controlled ventilation or a mechanical heat recovery ventilation (MHRV) system extracts stale air and recovers the heat from it before bringing in fresh air. This is a critical part of any deep retrofit.
🔹 Renewable Energy
Solar PV panels generate free electricity from your roof. Combined with a heat pump, they can power your heating system during daylight hours. The SEAI solar grant of up to €1,800 plus 0% VAT makes solar one of the most popular retrofit measures.
💰 How Much Does Retrofitting Cost in Ireland?
Costs vary enormously depending on the age, size and condition of your home, and how many upgrades you carry out. Here are rough cost ranges for common measures (before grants):
🌿 Attic insulation: €1,500 – €3,500
🌿 Cavity wall insulation: €1,000 – €3,000
🌿 External wall insulation: €10,000 – €25,000
🌿 Windows and doors: €10,000 – €20,000+
🌿 Heat pump system: €10,000 – €24,000
🌿 Solar PV panels: €6,000 – €15,000
🌿 Ventilation system: €3,000 – €6,000
A full deep retrofit of a typical 3-bed semi from a D rating to B2 might cost €40,000 to €70,000 before grants. After SEAI grants (which can cover 30-50% of costs through the One Stop Shop route), the net cost to the homeowner is significantly reduced.
For homeowners who cannot afford a full deep retrofit in one go, the good news is that the 2026 grants are specifically designed to support a phased approach – you can do insulation now, windows next year and a heat pump after that, claiming individual grants as you go.
💚 Grants Available for Retrofitting in 2026
The National Residential Retrofit Plan 2026 offers the most generous package of retrofit grants Ireland has ever seen. Total government funding for SEAI residential and community schemes in 2026 is €558 million, targeting 70,000 homes. Beyond SEAI, our home improvement grants guide rounds up every support available, and if the property has been empty for two years or more, the Vacant Property Refurbishment Grant can add up to €70,000 on top.
🔹 Insulation Grants by Dwelling Type
Grant amounts vary depending on the type of home you live in. Detached houses receive the highest grants because they have more exposed wall and roof area. Here is the full breakdown for 2026:
Attic insulation (from 3 February 2026):
🌿 Detached house: €2,000
🌿 Semi-detached or end-terrace: €1,300
🌿 Mid-terrace: €1,200
🌿 Apartment: €800
Cavity wall insulation (from 3 February 2026):
🌿 Detached house: €1,800
🌿 Semi-detached or end-terrace: €1,200
🌿 Mid-terrace: €800
🌿 Apartment: €700
Internal wall insulation (dry lining):
🌿 Detached house: €4,500
🌿 Semi-detached or end-terrace: €3,500
🌿 Mid-terrace: €2,000
🌿 Apartment: €1,500
External wall insulation:
🌿 Detached house: €8,000
🌿 Semi-detached or end-terrace: €6,000
🌿 Mid-terrace or apartment: €3,000
Floor insulation: up to €3,500 for houses
For attic and cavity wall insulation, the SEAI estimates that grants now cover approximately 80% of the average cost of the work. For external wall insulation, the grant covers between 20% and 35% of the median cost – it is a bigger job, but also delivers the most dramatic improvement.
🔹 Windows and Doors Grants (New for 2026)
From 2 March 2026, standalone window and door grants are available for the first time. Previously, window grants were only accessible through a full One Stop Shop deep retrofit.
Windows grant by dwelling type:
🌿 Detached house: €4,000
🌿 Semi-detached or end-terrace: €3,000
🌿 Mid-terrace: €1,800
🌿 Apartment: €1,500
Doors grant: €800 per external door, maximum two doors (€1,600 total)
To qualify for the windows and doors grant, your home must already meet a minimum fabric performance standard – either an HLI of 2.3 or better, or attic and walls noted as “Good” or “Very Good” on your BER Advisory Report. If your home does not meet this standard yet, you can upgrade insulation first and then apply for the windows grant.
🔹 Heat Pump and Heating Grants
🌿 Heat pump system: up to €12,500 (from February 2026) – this includes €6,500 for the heat pump, €2,000 for central heating upgrades and a €4,000 Renewable Heat Bonus
🌿 Heat pump system (apartments): up to €9,500
🌿 Air-to-air heat pump: up to €7,500
🌿 Heating controls: up to €700
🌿 Solar thermal: up to €1,200
For full details on heat pump costs, suitability and the step-by-step application process, see our complete heat pump guide.
🔹 Solar PV Grant
🌿 Solar PV: up to €1,800 (at 0% VAT)
See our solar panel grants guide for the full breakdown of the tiered grant calculation and export payment rates.
🔹 New for 2026 – Second Wall Measure
From 2 March 2026, homeowners who previously received a grant for cavity wall or internal wall insulation can now apply for a second wall insulation measure. This is a significant change – previously, if you had already used your wall insulation grant, you were locked out of further support.
This means you could, for example, get cavity wall insulation done first (the cheapest option) and then later add external wall insulation on top for maximum thermal performance. This makes your home warmer, cheaper to heat and heat pump-ready.
🔹 First-Time Buyer Attic Insulation Top-Up
First-time buyers of existing homes can claim a higher fixed grant for attic insulation of up to €2,500 – compared to the standard €2,000 maximum for a detached house. SEAI designed this specifically because first-time buyers who have just stretched to buy a house often have no spare cash for upgrades. In many cases, this enhanced grant covers most or all of the total cost of attic insulation.
🔹 Higher Grants for Qualifying Welfare Payment Recipients
From 2 March 2026, homeowners receiving qualifying welfare payments (the same payments that qualify for the Warmer Homes Scheme) can access higher fixed-amount grants for attic insulation and cavity wall insulation through the standard Better Energy Homes scheme.
🌿 Attic insulation: up to €2,500 (welfare payment recipients)
🌿 Cavity wall insulation: up to €2,300 (welfare payment recipients)
🌿 Enhanced BER grant: €280
In many cases, these enhanced grants cover most or all of the total cost of the work. This is designed to help people who are on the Warmer Homes Scheme waiting list (which can take 24 months or more) to get their attic and walls done immediately through the individual grants route instead.
Importantly, using these enhanced individual grants does not affect your place on the Warmer Homes Scheme waiting list for other measures like external wall insulation or heating upgrades.
🔹 Landlord Tax Relief for Retrofitting
Landlords can deduct up to €10,000 (net of any SEAI grant received) from their rental income for retrofit works. From 2026, this relief is available on up to three properties (increased from two), covering works carried out between 2026 and 2028.
This helps address the “split incentive” problem in the rental sector – where tenants benefit from lower bills but landlords pay for the upgrades. The tax relief, combined with SEAI grants, means landlords can substantially offset the cost of bringing rental properties up to standard.
🔹 Summary of Key Grants
🌿 Heat pump system: up to €12,500 (from February 2026)
🌿 Attic insulation: up to €2,000 for detached homes (€2,500 for first-time buyers and welfare payment recipients)
🌿 Cavity wall insulation: up to €1,800 for detached homes (€2,300 for welfare payment recipients)
🌿 External wall insulation: up to €8,000 for detached homes
🌿 Windows: up to €4,000 for detached homes (from March 2026)
🌿 Doors: up to €800 per door, maximum two doors (from March 2026)
🌿 Solar PV: up to €1,800
🌿 Heating controls: up to €700
🌿 Solar thermal: up to €1,200
For the full breakdown of every grant, see our complete SEAI grants guide.
🔹 One Stop Shops vs Individual Grants
There are two main routes to retrofitting with SEAI support:
Individual grants (Better Energy Homes) – you manage the project yourself, choose your own SEAI-registered contractors and apply for grants for each measure individually. Best for homeowners doing one or two upgrades at a time.
One Stop Shops – an SEAI-registered company manages the entire retrofit from start to finish, including the BER assessment, design, contractor management and grant applications. One Stop Shops can access grants of up to 50% of costs for deep retrofits achieving B2 or better. There are currently 14 registered One Stop Shops operating across Ireland.
From 2026, the One Stop Shop rules have been relaxed. The minimum energy uplift requirement and the requirement for a pre-works BER of B3 or worse are both being removed where a heat pump is installed. This means more homeowners can access the 50% grant route.
🔹 Low-Cost Retrofit Loans
The Home Energy Upgrade Loan Scheme offers government-backed loans of €5,000 to €75,000 at rates starting from 2.99%. Available through AIB, Bank of Ireland, PTSB, Avant Money (via An Post) and participating credit unions. The upgrade must be supported by an SEAI grant and projected to achieve at least a 20% improvement in energy performance. Full details in our loan scheme guide.
🏘️ The Warmer Homes Scheme – Free Energy Upgrades
The SEAI Warmer Homes Scheme provides fully funded energy upgrades to eligible homeowners at no cost whatsoever. This is not a grant where you pay upfront and claim back – SEAI manages the entire process, appoints contractors and covers all costs.
In 2024, the scheme completed 7,743 free home upgrades – a 31% increase on the previous year. The average cost per upgrade has risen dramatically, from around €2,600 in 2015 to just under €29,000 in early 2025, reflecting the shift from basic attic insulation top-ups to full deep retrofits including external wall insulation and heat pumps.
🔹 Who Qualifies?
To qualify for the Warmer Homes Scheme, you must meet all of these criteria:
🌿 You must own and live in your home as your main residence
🌿 The home must have been built and occupied before 2006
🌿 The home must have a BER of C or lower (if you do not have a BER, SEAI will do a free assessment)
🌿 You must receive one of the qualifying welfare payments: Fuel Allowance, Working Family Payment, Jobseeker’s Allowance (6+ months with a child under 7), Disability Allowance, Domiciliary Care Allowance, One Parent Family Payment or Carer’s Allowance
🔹 What Does It Cover?
The scheme covers attic insulation, wall insulation (cavity, internal or external), draught-proofing, lagging jackets, energy-efficient lighting, ventilation and – where recommended by the SEAI surveyor – heating system upgrades and window replacements.
Since January 2025, the scheme no longer installs fossil fuel boilers. If your home needs a new heating system, it will be a heat pump or another renewable option.
Windows are only replaced if your walls are being insulated at the same time and the existing windows are single-glazed. The SEAI decides on a case-by-case basis.
🔹 The Waiting List
The biggest challenge with the Warmer Homes Scheme is the waiting time. SEAI currently estimates 24 to 26 months from application to completion of works. The survey stage alone takes approximately 14 months from application.
Applications are processed on a first-come, first-served basis, with priority given to older and poorer-performing homes.
This is why the new enhanced individual grants for welfare payment recipients (from March 2026) are so important. If you qualify for the Warmer Homes Scheme but cannot wait two years for attic or cavity wall insulation, you can get these done immediately through the individual grants route at the enhanced rate – and keep your place on the Warmer Homes waiting list for the bigger measures.
🏘️ Community Energy Grants
The SEAI Community Grant supports area-based retrofit projects where multiple homes and community buildings are upgraded together. These projects are coordinated by SEAI-registered Community Project Coordinators and can include homes, schools, sports clubs and other community facilities.
Community projects often achieve better value than individual retrofits because contractors can work at scale across multiple properties in the same area. Homeowners participating in a community scheme can access the same grant rates as the individual and One Stop Shop routes.
Ireland’s Sustainable Energy Community (SEC) network now includes hundreds of communities across the country. If your local area has an SEC, they can help organise group upgrades and connect you with project coordinators. Check the SEAI community project map to see what is happening in your area.
🏘️ Local Authority and Social Housing Retrofitting
Budget 2026 includes €140 million to retrofit 3,500 local authority homes. The Climate Action Plan targets 36,500 social homes retrofitted by 2030, representing one quarter of the local authority housing stock.
From 2026, local authorities can also access Better Energy Homes grants for attic insulation, cavity wall insulation and heating controls in their housing stock – in addition to the deeper retrofit programme funded by the Department of Housing. This means local authorities now have more flexibility to do faster, lighter-touch upgrades alongside the full deep retrofit programme.
SEAI has also proposed increasing the grant rate available to Approved Housing Bodies (AHBs) to provide additional support for upgrading their worst-performing homes.
📊 Where Does Ireland Stand on Retrofitting?
Since 2019, the government has invested over €1.67 billion in energy upgrades across more than 244,000 homes. In 2024 alone, 53,984 homes received SEAI-supported upgrades – a 13% increase on 2023. Of those, 21,817 were upgraded to BER B2 or better.
In 2025, over 58,000 homeowners benefited from SEAI upgrade schemes. However, reaching the 500,000 B2 target by 2030 requires an average of 75,000 B2-equivalent upgrades per year from 2026 to 2030. That is a significant step up from current rates.
The SEAI has acknowledged that application growth has softened as energy prices have stabilised and the urgency of the 2022-2023 energy crisis has faded. The 2026 grant increases are designed to reignite momentum.
📋 How to Start Your Retrofit
🌿 Step 1: Get a BER assessment – book an SEAI-registered assessor to evaluate your home and provide an Advisory Report with recommended upgrades. This costs €150 to €300 and tells you exactly where your home is losing energy. See our BER rating guide for details.
🌿 Step 2: Decide your approach – are you doing a full deep retrofit through a One Stop Shop, or tackling individual measures step by step?
🌿 Step 3: Get quotes – get at least three quotes from SEAI-registered contractors. For a One Stop Shop route, contact several registered providers.
🌿 Step 4: Apply for grants – apply through SEAI’s online system before any work begins. You must have grant approval in place first.
🌿 Step 5: Complete the work – your contractors carry out the upgrades.
🌿 Step 6: Get a new BER – after completion, a new BER assessment confirms your improved rating.
🌿 Step 7: Claim your grant – submit the paperwork and receive your grant payment, typically within four to six weeks.
❓ Frequently Asked Questions About Retrofitting in Ireland
🔹 What does retrofitting mean?
Retrofitting means upgrading an existing building to improve its energy efficiency. For homes, this typically includes insulation, heating system upgrades, window replacements, ventilation improvements and renewable energy installations.
🔹 How much does a full retrofit cost?
A full deep retrofit of a typical 3-bed semi from D to B2 rating costs approximately €40,000 to €70,000 before grants. After SEAI grants (up to 50% through One Stop Shops), the net cost is significantly lower. Individual measures like attic insulation can cost as little as €1,500 before grants.
🔹 What grants are available for retrofitting in 2026?
SEAI offers grants for insulation (varying by dwelling type), heat pumps (up to €12,500), solar panels (up to €1,800), windows (up to €4,000 – new for 2026), doors (up to €800 each), heating controls and more. Total funding for 2026 is €558 million targeting 70,000 homes. See our full SEAI grants guide.
🔹 Do I have to do everything at once?
No. The 2026 grants are designed to support a phased approach. You can do attic insulation this year, walls next year and a heat pump after that, claiming individual grants for each measure. Alternatively, a One Stop Shop can manage a full deep retrofit in one project.
🔹 Can I get a second wall insulation grant?
Yes, from 2 March 2026. If you previously received a grant for cavity wall or internal wall insulation, you can now apply for a second wall insulation measure. This allows you to improve thermal performance further and make your home heat pump-ready.
🔹 I’m a first-time buyer – are there extra grants?
Yes. First-time buyers of existing homes can claim up to €2,500 for attic insulation – higher than the standard maximum. SEAI designed this because first-time buyers are often cash-poor after buying. In many cases, this enhanced grant covers most or all of the cost.
🔹 I’m on welfare payments – do I get more support?
Yes. From March 2026, homeowners on qualifying welfare payments can access higher individual grants for attic insulation (up to €2,500) and cavity wall insulation (up to €2,300). These enhanced rates often cover the full cost. You can also apply for the fully funded Warmer Homes Scheme, though waiting times are currently 24-26 months.
🔹 What is a One Stop Shop?
An SEAI-registered company that manages your entire retrofit project from start to finish – BER assessment, design, contractor management, grant applications and post-works certification. There are 14 registered One Stop Shops operating in Ireland. From 2026, the eligibility rules have been relaxed where a heat pump is installed.
🔹 How long does a retrofit take?
Individual measures like attic insulation can be done in a day or two. A full deep retrofit through a One Stop Shop typically takes 4 to 12 weeks depending on the scope of work and contractor availability.
🔹 Will retrofitting disrupt my daily life?
There will be some disruption, particularly for measures like external wall insulation or window replacement. However, most people continue living in their home throughout the process. A good contractor will minimise disruption and keep you informed at every stage.
🔹 I’m a landlord – can I claim grants and tax relief?
Yes. Landlords can apply for all the same SEAI grants as owner-occupiers. On top of that, you can deduct up to €10,000 (net of grants) from rental income for retrofit works, on up to three properties from 2026 to 2028. Between the grants and tax relief, the net cost of upgrading a rental property is substantially reduced.
🔹 What about biomass boilers?
SEAI does not offer individual grants for domestic biomass boilers under the Better Energy Homes scheme. Biomass may be considered through the One Stop Shop route where a heat pump is not suitable. The grant system is focused on heat pumps as the primary replacement for fossil fuel heating.
📚 Related Guides
🌿 SEAI Grants
🌿 Home Improvement Grants
🌿 Warmer Homes Scheme
🌿 Windows & Doors Grant
🌿 Vacant Property Grant
🌿 Boiler Replacement Grant
🌿 Electric Car Grant
🌿 Home Energy Upgrade Loan
👉 All guides and calculators
Climate Jargon Buster is an independent resource providing plain-English information on climate, energy and sustainability topics for an Irish audience. Grant amounts and costs in this article are correct as of March 2026. For the latest official information, visit seai.ie. This site is not affiliated with SEAI – always check the official website for current figures and eligibility requirements.