Things that can go wrong with your retrofit — and how to avoid them

This is the most common and most expensive mistake. If you start any retrofit work before SEAI approves your grant application, you are permanently disqualified. There are no exceptions. Always get written approval from SEAI before a contractor lifts a tool.

What to do instead: Apply through SEAI, wait for written confirmation, then start work.

SEAI will not pay your grant if your contractor is not on their register. Always check at seai.ie/contractor-register before signing anything. Do not take the contractor's word for it — check yourself.

A contractor can be SEAI registered when they quote and unregistered by the time they do the work. Check their registration again just before work starts.

What to do instead: Check SEAI registration at three points — when you get the quote, when you sign the contract, and just before work starts.

You must choose one route — the One Stop Shop deep retrofit route or individual grants. You cannot do both on the same property. If you start with One Stop Shop you cannot then switch to individual grants and vice versa.

What to do instead: Decide which route suits you before applying. If you are doing 3 or more major upgrades, the One Stop Shop may offer better value. For one or two upgrades, individual grants are simpler.

Since March 2026 windows are available as a standalone grant but your attic and walls must be rated Good or Very Good on your BER Advisory Report first. If they are not you will not get the windows grant until you insulate.

What to do instead: Get a BER assessment first. If your attic and walls need work, do those first (they are also grant-funded), then apply for the windows grant.

Most grants can only be claimed once per property. Wall insulation is now an exception — it can be claimed a second time as of 2026. Everything else is once only.

SEAI pays the grant after work is completed and inspected. You pay the contractor in full first and claim the grant back. Make sure you have the funds to cover the full cost before you start.

What to do instead: Budget for the full cost upfront. The Home Energy Upgrade Loan at 2.99% APR can bridge the gap.

Some contractors ask for 30–50% upfront. You are not obliged to pay this. Ask for stage payments tied to delivery of materials and completion of work. Always get a written contract before paying anything.

Retrofit costs vary enormously. Getting only one quote can mean overpaying by thousands. Always get at least three quotes from SEAI-registered contractors before committing.

What to do instead: Use our contractor directory to find SEAI-registered contractors in your county. Call at least three.

Some retrofit works qualify for the 9% reduced VAT rate, not 23%. Some contractors charge 23% when 9% should apply. Ask your contractor to confirm the correct VAT rate in writing before signing.

If you are on the Warmer Homes waiting list and you privately install attic or cavity wall insulation, you may lose your place on the list. However from March 2026 you can get attic and cavity wall insulation done immediately through enhanced individual grants without losing your Warmer Homes place. Check seai.ie/warmer-homes before doing anything.

The Warmer Homes Scheme is brilliant but the current waiting time is 24–26 months. If you need work done sooner you may need to use the individual grant route instead.

If you receive Fuel Allowance, Job Seekers Allowance, One Parent Family Payment or certain other social welfare payments you may qualify for the Warmer Homes Scheme where SEAI upgrades your home completely free. Check before you spend any money.

What to do instead: Check seai.ie/warmer-homes or call SEAI on 01 808 2100 to check your eligibility before spending anything.

External wall insulation changes the appearance of your home and may require planning permission, particularly in housing estates, conservation areas or protected structures. Check with your local authority before proceeding. Getting this wrong can result in enforcement action requiring you to remove the insulation.

What to do instead: Contact your local authority planning department before signing any external insulation contract. Most standard suburban homes are fine, but it is always worth checking.

Always ask for references from recent local jobs. A good contractor will have them. If they cannot provide references from similar work in your area, keep looking.

Never let work start without a written contract that specifies exactly what work will be done, the price, the payment schedule, and the timeline. A verbal agreement is very hard to enforce.

If a contractor visited your home to sign the contract you have 14 days to cancel under EU consumer law and recover any deposit paid. If you signed in their office or online this right may not apply.

A cold bridge is where heat escapes through gaps in your insulation at wall junctions, window reveals, floor edges and lintels. Very common in Irish homes built before the 1990s.

If your home has significant cold bridges you may still have cold spots and damp patches even after insulating. External wall insulation is the most effective solution as it wraps the whole wall.

What to do instead: Ask your contractor specifically about cold bridges before work starts. If they do not mention cold bridges, ask them how they plan to address them.