Constructive Voices · Data Report

Retrofitting in Ireland: the 2026 report

Ireland has never spent more on home energy upgrades, never completed more of them, and never been further behind on the one number that actually counts. This is what the 2026 data says — and what it means for the people doing the work.

Published August 2026 · Sources: SEAI, DCEE, ESRI, TU Dublin IBSO

A1B2 — THE TARGETG

On 9 January 2026, the Sustainable Energy Authority of Ireland published its end-of-year statement for 2025. It was, by the agency's own account, the best year in its history: over 58,000 home energy upgrades, a record €645 million invested, more than 8,000 free upgrades for households at risk of fuel poverty, and a third of all Ireland's grant-aided solar installations delivered in a single twelve months.

One figure was not in the list.

When we last surveyed this ground in Retrofitting in Ireland in 2025 and Beyond, the question was whether delivery could scale fast enough. A year on, delivery has scaled — and the question has changed.

The previous January, announcing the 2024 results, the government had led with it: 21,800 BER B2 upgrades, up 24 per cent year on year. B2 is the standard the entire National Retrofit Plan is built on — the definition of a "deep retrofit", the unit in which Ireland's 500,000-home target by 2030 is denominated. In the 2025 highlights, it does not appear.

That absence is the story of Irish retrofit in 2026. Not a failure of delivery — delivery is up, sharply, on almost every measure. A failure of the delivery to match the metric it was designed to serve, and a policy response that has quietly changed the subject.

The 2026 picture in seven numbers

58,000+Home energy upgrades supported by SEAI in 2025 — the highest on record, and 8% up on 2024.
11.5%Share of the 500,000-home B2 target delivered by end-2024, per the ESRI's March 2026 review.
3.5%Share of the 400,000 heat pump target delivered over the same period.
75,000B2-equivalent upgrades needed every year from 2026 to 2030. The 2024 rate was 21,817.
73,000Total upgrades targeted for 2026 — a headline count, not a B2 count.
€42,900Median homeowner contribution to a deep retrofit of a detached house, after grants.
24–26
monthsCurrent wait from application to completed works under the Warmer Homes Scheme.

01 / The arithmeticThe gap is not narrowing fast enough to close

Ireland's residential decarbonisation targets have been stable since the 2019 Climate Action Plan: upgrade 500,000 existing homes to a Building Energy Rating of B2 or better, install 400,000 heat pumps in existing dwellings, and serve up to 2.7 TWh a year of heat demand through district heating — all by 2030.

In March 2026, the Economic and Social Research Institute published a special article in its Spring Quarterly Economic Commentary reviewing progress. The authors — Muireann Lynch, Miguel Tovar and Niall Farrell — put the position plainly: delivery is materially off-track. Their table, built from SEAI administrative data, is the clearest single view of where Ireland actually stands.

Deep retrofits (BER B2 or better) and heat pump installations, 2019–2024
Year	Deep retrofits	Heat pumps
2019	2,423	1,130
2020	3,275	1,454
2021	4,340	1,972
2022	8,476	2,271
2023	17,601	3,769
2024	21,817	3,600
Total to end-2024	57,932	14,194
2030 target	500,000	400,000
Progress	11.5%	3.5%

Source: ESRI, A Review of Residential Heat Decarbonisation in Ireland (March 2026), Table 1, drawn from SEAI National Retrofit Plan Full Year Report 2024.

Deep retrofits to B257,932 of 500,000

11.5% of 2030 target

Heat pumps in existing homes14,194 of 400,000

3.5% of 2030 target

District heating (homes served)up to 60,000 of 187,000–314,000

20–32% of 2030 target

The trajectory matters more than the level. The ESRI fitted a linear trend to 2022–2024 — excluding the Covid years, when construction was curtailed — and projected it forward. Even assuming that rate of acceleration is sustained every year to 2030, deep retrofits reach roughly 334,000, or two-thirds of target. Heat pumps reach about 51,400, under 13 per cent. On the same basis, annual retrofit output never passes 75,000 by 2030 at all.

That 75,000 figure is not the ESRI's. It is SEAI's own. In the 2024 Full Year Report, the agency stated that meeting the 2030 target requires delivering, on average, 75,000 B2-equivalent upgrades per year from 2026 to 2030. Against a 2024 outturn of 21,817, that is a requirement to more than triple annual deep-retrofit output and hold it there for five consecutive years.

The rate of installation of retrofits has been c. 21k in 2024, much lower than the 75,000 retrofits required per annum.ESRI, A Review of Residential Heat Decarbonisation in Ireland, March 2026

Recommended listening · Season 4, Episode 22

Ireland’s Retrofit Race — with Dr. Ciarán Byrne, SEAI

The Director of the National Retrofit Directorate is the man accountable for the number in this section. He sets out where the programme stands, what actually moves the needle, and why he calls it “no-regrets work”.

02 / The pivotWhat the January 2026 plan actually changed

On 27 January 2026, Minister for Climate, Energy and the Environment Darragh O'Brien announced a new National Residential Retrofit Plan, backed by a record €640 million in Budget 2026 and targeting 73,000 home energy upgrades for the year. Read alongside the delivery data, the design of the package is revealing.

Principal measures introduced under the National Residential Retrofit Plan 2026
Measure	Live from	Depth
Uplift to cavity wall and attic insulation grants	3 Feb	Shallow
Heat pump system grant consolidated to €12,500 max (€6,500 heat pump + €2,000 radiators/pipework + €4,000 renewable heating bonus)	3 Feb	Deep
High-temperature heat pump pilot scheme	3 Feb	Pilot
New windows and doors grant, subject to a fabric standard	2 Mar	Shallow
Attic insulation grant for first-time buyers of existing homes	2 Mar	Shallow
"Second wall" measure — a further wall grant after a first	2 Mar	Shallow
Enhanced fixed grants for those on qualifying welfare payments	2 Mar	Shallow
AHB and fuel-poor grant rates raised to c.75% / c.80% of cost	Q1	Deep

Source: gov.ie press release, 27 January 2026. "Depth" classification is Constructive Voices' own, based on whether the measure alone can move a dwelling toward B2.

Six of the eight headline measures are individual, step-by-step upgrades accessed through the existing Better Energy Homes scheme. Most cannot, on their own, deliver a B2. The One Stop Shop route — the only pathway explicitly built around reaching B2 in a single project — is retained and benefits from the uplifts, but it is not where the new design energy went.

Recommended listening · Season 3, Episode 22

Cavity Wall Insulation: A Hidden Crisis — with Damian Mercer

Ireland is about to push a great deal of volume through cavity wall grants, including a new second-wall measure. Damian Mercer of Cavity Extraction has spent a decade removing insulation that failed — wrong product, wrong wall, wrong exposure — and explains how a subsidised measure becomes a damp problem.

SEAI has been open about the reasoning. Writing in April, chief executive William Walsh noted that most homeowners adopt a step-by-step approach and may not reach a B2 first time — and that the agency supports that approach. As a reading of homeowner behaviour, that is almost certainly correct. As a delivery strategy against a target denominated entirely in B2s, it creates an obvious tension.

The first quarter told on it

In April, the Minister brought Q1 2026 figures to Cabinet. Applications across all schemes reached 29,000, up 96 per cent year on year; applications for individual upgrades were up 186 per cent. Broken out by measure, the composition is stark.

SEAI grant applications, Q1 2026
Measure	Applications	Change YoY
Solar PV	10,000+	+65%
Windows and doors	7,000+	new grant
Attic insulation	1,730+	+81%
Cavity wall insulation	1,000+	+62%
Heat pump installations	350+	+95%

Source: gov.ie press release, 21 April 2026. Applications are not completions; completion lags application by months to years depending on scheme.

Every one of those percentage increases is real, and the heat pump figure is the fastest-growing of the set. But the base is the point. For every heat pump application in the first quarter of 2026, there were roughly twenty applications for windows and doors, and nearly thirty for solar PV. Actual heat pump installations to end-March numbered just over 900.

Sourcing note — an unpublished figure

SEAI's January 2026 end-of-year statement lists 2025 outputs but does not include a B2 count. The last published cumulative figure we could verify is "over 69,000 B2s" from 2019 to mid-year 2025, given by the Department of Climate, Energy and the Environment to RTÉ in July 2025. Against the ESRI's end-2024 total of 57,932, that implies roughly 11,000 B2 upgrades in the first half of 2025 — but a full-year 2025 figure was not available at the time of writing.

Anyone quoting a 2025 B2 number should source it to the SEAI National Retrofit Plan Full Year Report 2025 directly rather than reconstructing it.

03 / The costWhat a deep retrofit asks of a household

The ESRI's most uncomfortable contribution was not the target arithmetic. It was the household balance sheet, drawn from SEAI's own One Stop Shop scheme data.

Median deep retrofit cost and homeowner exposure, by dwelling type
Dwelling	Total cost	After grants	Monthly repayment
Apartment	€22,914	€16,378	€294
Detached house	€66,503	€42,900	€770

Source: ESRI (March 2026), from SEAI One Stop Shop scheme data. Repayments assume the full homeowner contribution borrowed over five years at 3%, the rate available under the government-backed Home Energy Upgrade Loan Scheme.

The ESRI set those repayments against household norms: 35.1 per cent of an average mortgage repayment for the apartment, and 97.6 per cent for the detached house. A detached-house deep retrofit, financed at a subsidised rate, is close to a second mortgage for five years.

Against that, the modelled energy saving is just under €700 a year for the apartment and just under €900 for the detached house, assuming a pre-retrofit D rating.

The payback arithmetic, done plainly

Dividing the homeowner's own contribution by the modelled annual energy saving — ignoring finance costs entirely, which flatters the result — gives a simple payback of roughly 23 years for an apartment and 48 years for a detached house.

These figures are Constructive Voices' calculation from the ESRI's published costs and savings. They are not a full appraisal: they exclude comfort, health, property value, carbon and energy-security benefits, all of which are real and none of which appear on a homeowner's bank statement.

SEAI's response to this framing, published in the Irish Independent on 1 April and reproduced on its own site, was that payback-period thinking takes an extremely narrow view of something that delivers far wider benefits — improvements to comfort and health that are immediate and do not amortise. Former Climate Minister Eamon Ryan made a similar argument in the Irish Times, warning that an overly negative reading risked damaging public confidence at exactly the wrong moment.

Both points are fair. Both also concede the underlying position: on the narrow financial case, deep retrofit does not currently pay for itself within a normal ownership horizon for most detached houses, and policy has not yet closed that gap.

Cost is not the only barrier

The ESRI's synthesis of the literature identifies several others, and they are not all solvable with money:

Disruption. Households value the inconvenience of retrofit works at a median €9,000 for minor disruption and €24,000 for major disruption — the sum they would need to be paid to accept it. Unlike capital cost, this cannot be amortised.
Disengagement. Around 21 per cent of homeowners consider their renovation work finished; a further 23 per cent say they would not dream of making major changes to their home. Over 40 per cent are therefore unlikely ever to deep retrofit — yet fewer than 5 per cent of the building stock has actually been deep retrofitted.
Split incentives. A landlord captures the property-value uplift but rarely the bill savings. Upgrading the private rental stock is estimated at €7–8 billion, and most landlords cannot afford a €25,000-plus retrofit.
Administrative friction. Nine per cent of eligible low-income households abandon their Warmer Homes application even though the work is free, with communication cited as the driver. Older households disproportionately cite administrative complexity.

04 / The measurementDoes a B2 mean what the target assumes?

This is the section that should concern anyone in the built environment professionally, because it questions not the pace of delivery but the validity of the unit.

A BER is a calculated benchmark, not a measurement. An SEAI-registered assessor models fabric, heating, ventilation, lighting and renewables in DEAP, using standardised assumptions about occupancy and weather. It predicts what a dwelling's energy use is likely to be under standard conditions. It does not observe what it is.

Irish research has repeatedly found the two diverge — and, critically, that they diverge in different directions at different ends of the scale.

Deviation between BER-predicted and actual energy use, by rating band
Band	Actual vs prediction
A or B rated	39.6% above prediction
D rated	24% below prediction
E rated	39% below prediction
F or G rated	56% below prediction

Source: Coyne & Denny (2021), Mind the Energy Performance Gap, as summarised in ESRI (2026). Theoretical energy use across the sample averaged 17% below actual use.

The consequence, when you follow it through, is startling. In the Coyne and Denny sample, average measured consumption barely varies by band at all: around 10,569 kWh a year for A-rated dwellings against 10,964 kWh for F and G-rated ones, on a sample average near 10,869 kWh.

The mechanism is contested. The leading explanation is the rebound and prebound pair: households in poorly insulated homes under-heat because they cannot afford not to, and when the fabric improves they take the benefit as warmth rather than as a smaller bill. Irish work on social housing tenants found exactly that pattern. Standardised DEAP inputs that differ from real occupancy behaviour account for more of it. And there is evidence of bunching in post-works ratings just above band thresholds — homeowners specifying renovations to clear a grade, not to minimise demand.

Why this matters for the target, not just the metric

If B2-rated dwellings consume materially more than DEAP predicts, then 500,000 B2 upgrades will not deliver the emissions reduction the Climate Action Plan has banked on them delivering. The ESRI's conclusion is blunt: even in the event of the targets being met, the decarbonisation realised may be insufficient. Should we quantify performance with error, progress will be measured with error.

The solar route to B2

A March 2026 study from the Irish Building Stock Observatory at TU Dublin, published in Energy Policy, made the point concrete. Examining case studies of C-rated homes, the researchers identified what they termed a critical gap in Ireland's rules: a dwelling can reach B2 without any substantial reduction in heat demand, by installing solar PV.

One case study — an extended 1980s three-bed semi-detached — did precisely that. At B2, the researchers noted, the house would still not be considered heat-pump ready.

The market has noticed. In 2025, more than 30,000 Irish homeowners drew down solar PV grants, a record. In the same year, 4,360 drew down heat pump grants. Solar PV's appeal is not mysterious: a five-to-ten-year payback, minimal disruption, no need to vacate, and a flat €1,800 grant held at 2025 levels for 2026.

If you look at what drives our peak national demand load, it's cold weather. During cold snaps, even in your B2 or indeed A-rated home, you will still be turning on your heat.Ciara Ahern, Irish Building Stock Observatory, TU Dublin

For practitioners this is the crux. A B2 achieved through fabric improvement and a B2 achieved through generation are the same certificate and radically different buildings. Only one is a platform for low-temperature heating. Only one reduces the peak winter load that dictates grid investment. The certificate does not distinguish them; the physics does.

05 / Heat pumps2042, on current trends

Ireland is not a laggard on heat pumps by European standards — we set out where it actually sits in where Ireland ranks in Europe for green buildings. The problem is not the comparison. It is the target.

The TU Dublin team projected that on current trends Ireland reaches 400,000 heat pumps in existing homes in 2042 — twelve years late. Their diagnosis is more interesting than the date.

First, the comfort barrier. Over a third of Irish homes are C-rated: warm enough when the heating is on, with heating costs most households find manageable. For those homeowners, deep retrofit offers diminishing returns, and the research consistently finds that "comfortable enough" is where voluntary upgrade stops. C-rated stock is simultaneously the largest available pool and the least motivated.

Second, the grant criteria themselves. To qualify for a heat pump grant a dwelling must meet a specified Heat Loss Indicator. The researchers argue the HLI threshold has not kept pace with heat pump technology, which has improved to the point of being technically suitable for as many as three-quarters of Irish homes — considerably more than can currently qualify for support. Their recommendation is that the HLI criteria be reformed and that tailored measures for C-rated homes be developed.

SEAI has moved partway. The 2026 package adds a €4,000 renewable heating bonus within a consolidated €12,500 heat pump system grant, and has begun a pilot investigating heat pumps in houses without large insulation upgrades — alongside a separate high-temperature heat pump pilot to test whether running costs stay comparable to the fossil systems they replace. Both are the right questions. Neither has results yet.

Third, older apartments. The TU Dublin work warns that without targeted policy, older flats risk becoming stranded assets — prematurely devalued and left behind as the rest of the stock moves. Multi-unit developments remain, in the government's own words, a particularly difficult segment to retrofit.

06 / The queueWhere the deepest retrofits are actually happening

The Warmer Homes Scheme is the one part of the system that consistently delivers depth. It is fully funded, SEAI selects the measures, and the average value per home has risen from around €2,600 in 2015 to approximately €29,000 in 2025 and €31,000 in the first quarter of 2026. In 2025 it reached its highest level ever, with over 8,000 homes completed.

It is also the part of the system where the wait is longest. SEAI correspondence reported in November 2025 put the cycle at roughly fourteen months to survey, then a further ten to twelve months to completed works. Citizens Information gave the current range as 24 to 26 months from application to completion. Almost 45,000 applications were received between January 2022 and end-September 2025.

The 2026 plan's most practically useful reform addresses exactly this. From 2 March, homeowners on qualifying welfare payments can claim enhanced fixed grants for attic and cavity insulation — processed in weeks — without losing their position in the Warmer Homes queue for the deeper measures. It is a small change that does something none of the headline grant uplifts do: it gets heat into the homes that need it most while they wait.

Recommended listening · Season 4, Episode 14

A Sustainable Snapshot of Cobh: Local Action, Global Implications

National targets are delivered street by street. What climate action actually looks like on the ground in a Cork harbour town — older stock, a live retrofit programme, and rapid new development arriving at the same time.

The equity pattern, stated directly

Households that can pay get shallow measures quickly. Households that cannot pay get deep measures slowly. The scheme delivering genuine B2-level work at scale to the worst-performing stock is the one with a two-year queue, and the schemes delivering fastest are the ones least likely to produce a B2. That is not an accident of administration; it follows from a system in which depth is publicly funded and speed is privately purchased. The same pattern shows up locally: see sustainable building in Cork, where an EU Mission Label sits alongside one of the country’s lowest A-rated housing shares.

07 / The constraintFifteen thousand workers Ireland does not have spare

Underneath all of it sits a supply problem that no grant rate can solve.

Work cited by the ESRI estimates that 50,000 retrofits a year requires around 15,000 construction workers — approximately 8.5 per cent of total construction employment as at Q4 2024, or 20.8 per cent of those not mainly working on new housing. The government's own figures put the need at a construction sector expansion of 18,180 and recruitment of 22,779.

The sector is at full capacity. In the short run, labour and materials are fixed. To the extent that workers can move between new build and retrofit — and the ESRI is careful to treat full substitutability as an upper bound — every additional retrofit in an acute housing shortage comes at some cost to housing completions. Add the grid reinforcement and generation build-out that mass heat pump deployment requires, and the same constrained labour pool is being asked to do a third job.

This is the trade-off that neither the retrofit target nor the housing target acknowledges in its own arithmetic, and it has not been quantified.

08 / For practiceWhat the 2026 data changes for people doing the work

Four things follow for architects, assessors, contractors and consultants working in this market.

The B2 certificate is no longer sufficient as a description of quality

If a client's B2 can be reached by fabric or by generation, and only one of those routes produces a heat-pump-ready, low-peak-demand building, then "we'll get you to a B2" has stopped being a meaningful specification. The useful conversation is about heat demand and heat loss indicator — the numbers that determine whether low-temperature heating will actually work — with the BER as the compliance output rather than the design objective. Practices that can hold that conversation credibly will be doing different work in 2027 than practices that cannot.

Fabric-first is now the differentiated position, not the default one

The grant landscape has tilted toward measures that are quick, cheap and popular. That is a rational response to homeowner behaviour and it will move a great deal of volume. It also means the professional case for fabric-first — airtightness, continuous insulation, thermal bridge control, ventilation designed alongside rather than after — has to be made rather than assumed. The evidence base for making it is stronger than it has ever been.

Verified competence is the scarce input

If Ireland is short 15,000 to 22,000 people, the constraint is not headcount alone but demonstrable capability: PHI Certified Passive House Designers and Tradespersons, NSAI-registered thermal modellers, SEAI-registered One Stop Shops and BER assessors, and airtightness testers with current certification. In a market expanding this fast, the gap between registered and merely available will widen — and it is the buyer's problem to detect. Credential-based verification is not bureaucracy here; it is the only practical filter.

The measurement question is a commercial opportunity

The ESRI's clearest recommendation is that policy adopt data-driven metrics and prioritise ex-post evaluation of outcomes, because otherwise underperformance is embedded by design. Irish researchers are already building the methods. Practices that can instrument what they deliver — measured airtightness, in-use monitoring, actual against predicted consumption — will be positioned for a procurement environment that is, on the current trajectory, going to start asking.

09 / ConclusionTwo problems, not one

Ireland's retrofit programme has a delivery problem and a definition problem, and they are frequently discussed as though they were the same thing. Retrofit is one row in a wider national scorecard — we track the rest in The State of the Built Environment in Ireland.

The delivery problem is severe but legible: not enough deep retrofits, far too few heat pumps, a labour ceiling, an affordability gap for detached homes, and a two-year queue for the households in the worst stock. Money, capacity and scheme design all bear on it, and 2026 has brought more of all three.

The definition problem is harder, because more delivery does not fix it. If a B2 can be bought with panels rather than fabric, and if B2 homes consume close to what G homes consume, then hitting 500,000 B2s would not deliver what the Climate Action Plan assumed it would buy. Ireland would meet the target and miss the point.

The 2026 plan is a serious, well-funded attempt at the first problem. Nothing in it addresses the second. That is the gap to watch for the rest of the decade — and it is the one the built environment sector, rather than the grant system, is best placed to close.

Methodology and sourcing

All delivery figures are taken from SEAI and Department of Climate, Energy and the Environment publications, or from the ESRI's March 2026 review, which draws on SEAI administrative data. Where this report calculates a figure rather than citing one — the simple payback estimates in section 03, and the "depth" classification of 2026 grant measures in section 02 — that is stated at the point of use.

Known data issues

Heat pump totals do not reconcile exactly. Summing the annual heat pump figures in the ESRI table gives 14,196; SEAI's stated 2019–2024 total is 14,194. SEAI has separately reported 3,609 installations for 2024 against the 3,600 in the table. The discrepancy is trivial in magnitude but real, and reflects SEAI's stated practice of refining reported figures between publications.
No published full-year 2025 B2 figure. See the sourcing note in section 02. Cumulative upgrades reconcile cleanly across releases — 186,000 to end-2024, 244,000 to end-2025, 257,000 to end-Q1 2026 — but the B2 subset does not carry through.
Applications are not completions. Q1 2026 application growth is genuinely large; it will show up in completion data over 2026 and 2027, discounted by drop-out.

Primary sources

ESRI, A Review of Residential Heat Decarbonisation in Ireland, QEC Special Article, March 2026
DCEE, National Residential Retrofit Plan 2026 grant package, 27 January 2026
DCEE, Q1 2026 retrofit update to Cabinet, 21 April 2026
SEAI, 2025 end-of-year statement, 9 January 2026
SEAI, The value of retrofitting goes well beyond the numbers, William Walsh, 1 April 2026
SEAI, National Retrofit Plan Full Year Report 2024
Essien-Thompson, Ahern et al., Irish Building Stock Observatory, TU Dublin, published in Energy Policy, March 2026
Coyne & Denny, Mind the Energy Performance Gap: Testing the Accuracy of Building Energy Performance Certificates in Ireland, Energy Efficiency, 2021

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Retrofitting in Ireland: the 2026 Report

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