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RetrofitReady is a free information service. We are not affiliated with SEAI or any government body. Grant figures are indicative only and may change without notice. Always verify current rates and eligibility at seai.ie before signing any contract or starting any work. We do not endorse or guarantee any contractor listed on this site.

Free tools for Irish homeowners

Retrofit calculators & tools

Work out your grants, costs, savings and system sizes before talking to a contractor. All free, no sign-up, instant results.

SEAI Grant Calculator Ireland 2026

Check exactly which SEAI grants apply to your home. Enter your property type, build year and planned upgrades to see your grant amounts instantly.

Check my grants

How Many Solar Panels Do I Need?

Enter your electricity usage, county and roof details. See the recommended system size, number of panels, annual generation and savings for your Irish home.

Size my solar system

Heat Pump vs Gas Boiler Cost Comparison

Compare annual running costs of a heat pump against your current gas or oil boiler. See how much you could save each year and your CO2 reduction.

Compare heating costs

Retrofit ROI Calculator — BER Upgrade Savings

Calculate the return on investment for upgrading your BER rating. See estimated costs, annual savings, payback period and property value increase.

Calculate my ROI

Battery Sizing Calculator for Solar

Find the right battery size for your solar PV system. Based on your daily usage and how many hours of backup you want.

Size my battery

Solar Panel Upgrade Calculator

Already have solar panels? See how much more you could generate and save by upgrading to higher wattage panels.

Check upgrade savings

Home Energy Savings Estimator Ireland

Enter your BER rating, heating system and planned upgrades to estimate your annual energy savings.

Estimate my savings

Solar Suitability Checker Ireland

Find out if your roof is suitable for solar PV panels, what you could generate per year, and your potential export income.

Check my roof

Commercial Solar Grant Calculator (NDMG)

Check non-domestic microgen grants for businesses, farms, schools and community buildings. Grants up to €162,600.

Check commercial grants

Retrofit Loan Comparison

Compare the 3% Home Energy Upgrade Loan Scheme with credit union and standard bank loans. See monthly repayments and total interest.

Compare loan options

BER Improvement Planner

Plan your upgrade path to reach your target BER rating. See recommended measures, costs, grants and the most cost-effective route.

Plan my BER upgrade

SEAI Grant Waiting Times

See current estimated SEAI grant processing times. Crowdsourced from real Irish homeowners who have been through the process.

Check waiting times

Want a personalised assessment?

Answer a few questions about your home and get a tailored grant breakdown, cost estimate and matched contractors.

Start my home check

Common questions about our calculators

Are these calculators accurate?

They use current 2026 SEAI grant rates and cost estimates based on typical Irish retrofit projects. Results are estimates — a BER assessor and contractor quotes will confirm exact figures for your home.

Do I need to sign up?

No. All calculators are completely free with no sign-up required. You can optionally save your results or get matched with contractors after seeing your estimates.

Which calculator should I use first?

Start with the SEAI Grant Calculator to see what grants you qualify for. Then use the specific calculators for the upgrades you are considering — solar sizing, heat pump comparison, or retrofit ROI.

Can I trust the grant amounts shown?

Grant amounts are sourced directly from SEAI published rates for 2026. Actual eligibility depends on your property specifics, which a BER assessment will confirm.

Do the solar calculators use Irish data?

Yes. Solar yield figures are based on county-level Irish irradiance data, with adjustments for roof orientation (south, east/west, north) and tilt angle.

Official SEAI Resource — always verify grant details directly with SEAI before applying.

Last verified: 2026-06-01