Methodology & data sources

How HomePlanIQ builds the estimate

HomePlanIQ combines the project inputs you provide with published source data and HomePlanIQ modelling assumptions. The estimate is an indicative planning range for a home project, not a quotation, valuation or guarantee.

Cost estimates

Some energy-upgrade measures use SEAI completed-project median cost data for January to December 2025. Where an official median is used, HomePlanIQ constructs its own low and high planning range around that median. Those HomePlanIQ low and high figures are not SEAI-published percentile ranges, quotations or forecasts.

Other measures use HomePlanIQ planning ranges based on reviewed Irish market guidance and modelling assumptions. Where a published source does not provide a directly comparable figure, the value is presented as a HomePlanIQ market-planning assumption rather than as an official median.

Costs are then adjusted by the selected work, area, quantity, finish level and specification inputs. Area-based measures such as wall insulation or extension work are estimated from the relevant unit area. Quantity-based measures such as windows, doors, bathroom count, solar panels and insulation areas use the entered quantities. Finish-level measures such as kitchen and bathroom renovation use the selected finish band, with higher finishes increasing the planning range. Window cost modelling adjusts the baseline according to entered quantity and specification using HomePlanIQ planning assumptions. Solar PV size and cost adjustments are also a HomePlanIQ modelling approach, not an SEAI pricing formula.

Grant estimates

Grant values shown in HomePlanIQ are based on the current published SEAI information and the answers supplied by the user. HomePlanIQ does not approve grants or determine final eligibility. Official SEAI rules, documentation and decisions take precedence over any calculator result.

HomePlanIQ compares the Individual Grants route and the SEAI One Stop Shop route at a high level where the selected project makes that comparison relevant. The calculator keeps the gross planned scope consistent when comparing routes so the difference reflects the potential grant treatment and route assumptions, not a different underlying project scope.

Grant amounts are capped against the estimated qualifying measure cost in the calculator rather than being allowed to offset unrelated work. Displayed grants can therefore be lower than a headline scheme maximum, or zero, depending on the selected measures, the estimated qualifying cost and the answers supplied. The final grant outcome can be lower or zero after official review.

What the calculator cannot establish

• actual occupancy date where SEAI requires both build and occupancy cut-offs
• MPRN, ownership and applicant evidence
• prior SEAI grant history
• contractor registration and completed-work compliance
• final HLI or technical assessment outcomes
• final BER or post-works performance
• whether all windows, doors and fabric technical requirements will be satisfied
• whether a traditional or heritage home requires the Traditional Homes Pilot
• final SEAI approval
• planning permission, building regulations, structural suitability or professional design
• actual contractor quotation

Traditional homes

Traditionally constructed homes, commonly older solid-masonry homes, may follow SEAI's Traditional Homes Pilot or the One Stop Shop pathway. HomePlanIQ does not determine eligibility for that scheme. The calculator does not treat every solid-wall home as a traditional home, and it does not decide which SEAI route is required. For official information, see the SEAI Traditional Homes information.

Data dates

Cost and grant information is tied to the dates stated in the relevant source notes. The cost data described above covers January to December 2025 where SEAI completed-project medians are used. Grant information follows the published scheme information available for the relevant review period. Source dates matter because official schemes and market costs can change.

Independence

HomePlanIQ is independent and is not affiliated with, endorsed by or part of SEAI. It provides a planning aid for homeowners, not an official government determination or grant approval service.

Privacy and contact

For privacy questions, contact info@homeplaniq.ie. For project or service questions, contact info@homeplaniq.ie as provided on the website. Your calculator answers are processed locally in your browser and are not sent to a HomePlanIQ backend or stored by HomePlanIQ.

Further information

For the current public legal notices, see the Disclaimer, Privacy Policy, Terms of Use and Cookies notice.

For the official privacy authority in Ireland, see the Data Protection Commission.