We see this all the time. A homeowner gets a quote, the contractor is available next week, and the work starts before anyone thinks to check the grant situation. Three weeks later, they find out they've just missed out on €12,500.
It's the most expensive mistake you can make with SEAI grants, and unfortunately it's also the most common.
The short answer: no. If work has already started, that grant is gone. No appeals, no exceptions (with one very narrow carve-out for windows, more on that below).
The rule is absolute
SEAI's position is clear: you must have written grant approval (your Letter of Offer) before any work begins. Start before that letter arrives and the grant is gone, permanently. There's no appeals process and no way around it.
SEAI reports that starting work before approval is the single most common reason homeowners lose out on grants. On a heat pump installation worth €12,500 in grants, that's a very costly mistake.
This applies to all SEAI home energy grants, insulation, heat pumps, solar PV, heating controls, windows and doors, and EV chargers.
What counts as "starting work"?
This is where it gets people. "Starting work" is broader than you'd think. It includes:
- Any physical work at all. even stripping old insulation or removing a window
- Buying materials. even if they're sitting in your garage unopened
- Having equipment delivered. that heat pump unit arriving on a pallet counts
- Paying a deposit to a contractor to secure a start date
We've heard of cases where a homeowner ordered solar panels online, had them delivered to their house, and then applied for the grant. Rejected. The delivery was considered "commencing works."
What you can do before applying (and should):
- Getting quotes from SEAI-registered contractors
- Having a BER assessment carried out
- Submitting the SEAI grant application itself
- Researching your options and planning the project
- Having a heat pump technical assessment (which has its own €200 grant)
The one exception: windows and doors (January 2026 onwards)
There is one limited exception to the rule. The new windows and doors grant was announced on 27 January 2026, but the application portal didn't open until 2 March 2026. SEAI confirmed that homeowners who ordered or commenced window/door work from 27 January 2026 onwards may still qualify for the grant, provided they use an SEAI-registered contractor and meet all other requirements.
This exception exists only because the grant was brand new and there was a gap between announcement and applications opening. It does not apply to any other grant type, and it does not apply to windows ordered before 27 January 2026.
What to do if you've already started work
If you've already started or completed an upgrade without SEAI grant approval, you unfortunately cannot claim the grant for that specific measure. However:
- You can still claim grants for other upgrades. If you installed attic insulation without a grant, you can still apply for cavity wall insulation, a heat pump, solar panels, or any other measure, as long as you apply and get approval before that work starts.
- You can claim a second wall insulation measure. From March 2026, if you previously received an SEAI grant for cavity or internal wall insulation, you can now apply for a second wall measure.
- You can still get a BER assessment to understand what other upgrades would benefit your home most. A BER assessor will survey your home and give you a prioritised list of improvements with estimated costs and savings, it's the best starting point before applying for any grant. Get a BER quote from Homerating.ie →
1. Get quotes from SEAI-registered contractors. 2. Apply for the grant online at seai.ie. 3. Wait for your Letter of Offer (usually arrives within days). 4. Accept the offer. 5. Only then, start the work. 6. Complete within 8 months (solar PV) or 6 months (other measures).
How long does approval take?
The good news is that SEAI grant approval is usually very fast, often immediate or within a few days for online applications. The Letter of Offer comes via email. So there's really no reason to skip the application step. A few days of patience can save you thousands.
For a full walkthrough of the application process, timelines, and what documentation you need, see our complete SEAI grants guide.
Before applying for any grant, a BER assessment tells you exactly where your home is losing heat and which upgrades will have the biggest impact. It typically costs €200–€350 and gives you a clear roadmap. Our parent company Homerating.ie provides fast BER assessments across Dublin, Meath, Wicklow, Kildare and Louth.
Planning an upgrade? Check your grants first
Use our free calculator to see exactly what grants your home qualifies for before you start.
Check My Grants →Key takeaways
The golden rule is simple: apply first, wait for the letter, then start. Online approval usually comes through in minutes, so there's no real reason to skip it. A few minutes of patience protects thousands of euro in grants. And if you've already missed out on one upgrade, don't let it stop you from claiming grants on the next one, each measure is a separate application.