BER Energy Cost Calculator

How Your BER Rating Affects Your Energy Bills and Property Value

A BER (Building Energy Rating) grades your home from A1 (most efficient) to G (least efficient). The gap in running costs is stark: an A-rated home typically costs around €900 per year to heat and power, while a G-rated home can cost €3,500 or more. Over a 30-year mortgage, that difference adds up to over €75,000 — more than most home renovations cost.

Impact on Property Value

Research consistently shows that improving a home by one or two BER grades increases its market value by 3–5%. On a €400,000 property, that's €12,000–€20,000 in added value from upgrades that might cost €5,000–€15,000 after SEAI grants. Buyers and renters increasingly filter by BER rating, so a poor rating also narrows your market if you're selling or letting.

Green Mortgage Discounts

Most Irish lenders offer green mortgage rates for homes with a BER of B3 or better — typically 0.1–0.2% below the standard rate. On a €350,000 mortgage over 30 years, a 0.15% discount saves roughly €9,000 in interest. If your BER is close to B3, upgrading before you buy (for new builds) or before you switch (for existing homes) could qualify you for the lower rate.

Most Cost-Effective Upgrades

Attic insulation delivers the best return — costing €1,000–€2,500 with SEAI grants covering up to 80%. Cavity wall insulation is next, at €1,000–€2,000 after grants. Heating controls and a modern condensing boiler or heat pump come after that. Solar PV panels are increasingly popular and can reduce electricity bills by 50–70%. Check your SEAI grant eligibility before starting any work, and get a BER assessment from Homerating.ie to know your starting point.

Related tools: Mortgage Comparison · Renovation ROI Calculator · SEAI Grant Calculator