How to boost your Building Energy Rating (BER)
Boosting your home’s energy rating can slash your energy bills, make your house warmer and even unlock cheaper mortgage deals. Here’s how to improve your BER and save money.
At a glance Ireland’s Building Energy Rating (BER)
- May 2026 changes: Ireland’s BER system has shifted to a simplified A-G scale under new EU rules, introducing a new “A0” category specifically for zero-emission homes.
- What it measures: A BER grades your home’s energy efficiency. High ratings (A0-B) mean a warmer home with significantly lower energy bills, while lower ratings (F-G) indicate poor heat retention and high running costs.
- When it is required: You must hire an SEAI-registered assessor to get a BER certificate before selling, renting, or occupying a newly built property. Once issued, certificates are valid for 10 years.
- How to boost your BER rating: You can improve your rating and cut annual heating bills by upgrading your insulation (attic and walls), installing energy-efficient windows, or adding renewable systems like solar panels and heat pumps.
- Grants and financial support: The SEAI offers substantial Home Energy Grants to help cover the costs of these upgrades. Additionally, achieving a rating of B or higher can unlock discounted “Green” mortgages and lower-rate personal loans from banks.
What is a Building Energy Rating (BER)?
A Building Energy Rating (BER) shows the energy performance of your home and grades your home’s energy efficiency on a scale of A0 to G.
A0 and A-rated homes are the most energy-efficient, while G-rated homes are the least. A good BER rating means your home is:
For instance, an A-rated house conserves heat better, so it needs less fuel to stay warm, which means you’ll benefit from lower energy costs. Whereas a G-rated home will lose heat more readily, you’ll need to work harder to retain warmth, and your energy bills will be higher.
Why is it required?
An owner must provide a BER to prospective buyers or tenants when a home is offered for sale or rent and homeowners must obtain a BER before a new home is occupied for the first time.
A BER is required on a dwelling when it is:
- Offered for sale off plans (provisional BER)
- A new dwelling for occupation
- Offered for sale or rent
- Undergoing work that requires a grant from SEAI
Exemptions apply to protected, historic structures and temporary or derelict properties.
The BER certificate
A BER certificate is required for the majority of homes for sale or rent in Ireland and BER details must be included in advertisements when a home is on the market.
Since 2007 all new homes are required to have a BER certificate. It ensures new dwellings are built with energy-efficient designs, materials, and appliances in line with the Government’s Sustainable Energy Policy.
How to get your BER Certificate
Download the certificate and advisory report on the SEAI National BER Register. You’ll need the MPRN number from an electricity bill and the BER number.
How much does a BER certificate cost?
There is no set fee for a BER certificate, so it’s wise to shop around to get the best price.
A typical home or an apartment of 1,200 sq could cost around €150 while a large house, duplex, or penthouse could cost between €200 and €300*.
Make sure you get written quotes before commissioning a BER assessment and check the following:
- Is the assessor insured and registered
- Is the price quoted inclusive of the SEAI Registration Charge
- Does the price include VAT
*Cost depends on property size, complexity, location, and quotes from assessors.
How long is a BER certificate valid?
A BER certificate is valid for 10 years provided there’s no change to your home that could affect the energy performance.
For unbuilt homes, a Provisional BER based on plans for your new home is only valid for 2 years.
What do the BER changes mean for me?
In May 2026, the Government introduced a new simplified Building Energy Rating (BER) for residential properties across Ireland.
The aim is to make BERs easier to understand and improve comparison across Ireland and the EU. It will also recognise the most sustainable homes by introducing the new A0 category for buildings with zero carbon emissions.
What is changing?
The old 15-point scale that used sub-level grades, like A1, A2, B1, B2, C3 to G, is being completely scrapped, and a new, simpler 8-point scale is being introduced with the categories: A0, A, B, C, D, E, F, and G.
The new A0 rating is to recognise true zero-emissions buildings that do not use fossil fuels.
The new BER Certificate will include a QR code that links directly to BER details and home‑upgrade information, making it easier for you to access guidance on improving your home’s energy performance.
Will my home be regraded?
No, the simplified ratings will apply only to properties that do not have a BER certificate before 24 May 2026.
Only new builds and properties that require a new certificate due to retrofits or energy upgrades will have the new rating system applied.
Is my existing BER Certificate still valid?
Yes, all existing BER certificates remain valid for 10 years from their date of issue. You do not need to do anything.
Will I now have to buy a new BER when I move?
No. The new BER grading does not affect existing certificates, which will remain valid for 10 years from their date of issue. You can continue to use your current BER when selling or renting your home, unless major renovations or energy upgrades change its energy performance.
Will the new rating affect my SEAI grant application?
No. The only change will be that the requirement to reach a B2-rating under the One Stop Shop Scheme or Community Energy Grant will now apply to reaching a B-rating post-works. The minimum required improvement in energy efficiency remains the same.
How to obtain a new BER
BERs are carried out by independent assessors registered with the Sustainable Energy Authority of Ireland (SEAI). The assessor will need between 30 minutes and an hour to do the inspection depending on the size of your home.
You can find a list of registered BER assessors at SEAI.ie. Just search in your area or check if an assessor is registered.
Finding a BER assessor
Using the SEAI’s BER assessor tool, shop around, get multiple quotes (at least three) and compare prices and information.
When dealing with assessors:
When you’ve chosen an assessor:
- Request a written agreement or contract (SEAI example here)
- Request a description of proposed services, costs and expenses
- Confirm your postal address, eircode and Meter Point Reference Number (MPRN)l
Before the assessment begins:
- Ensure any planned home improvements are complete
- Confirm documentation checklist
BER Checklist
Having the right documents at hand can ensure an accurate BER reading, so check that the documentation you’ve provided is sufficient.
If applicable to your property, provide information about:
Readying your home can also help the process go smoothly. Ensure:
- All areas are unlocked and accessible (e.g. attic, outdoor buildings and/or garage)
- All areas in your home that have been extended or upgraded are clearly marked
- You identify the heating system and heating controls
If you can’t provide some relevant documents, the BER assessor will use ‘default values’ or estimates, which could result in your home receiving a lower BER rating.
How is your BER calculated?
A BER is based on the calculated energy performance and associated carbon dioxide emissions from room and water heating, ventilation and lighting under standardised conditions.
Although a BER takes into account how many people live at the property, it doesn’t include electricity used for purposes other than heating, lighting, pumps and fans.
Used in the calculation are:
- the house dimensions
- the house orientation
- types of window
- level of insulation
- heating & hot water system efficiencies
What does the rating mean for your property?
Ireland’s Building Energy Rating (BER) shows how efficiently a home uses energy for heating, hot water and lighting. Homes with a higher BER are better insulated and need less energy to stay warm - meaning lower running costs and fewer carbon emissions.
The table below outlines each rating, an example home and what it might mean in practice.
| BER grade | Example home and what it means in practice | |
|---|---|---|
| AO | Home that does not use fossil fuel; highly efficient, a zero-emission building | |
| A | Excellent efficiency; most new urban homes with solar panels (NZEB) | |
| B | Efficient, modern home with upgrade, retrofitted or modern property | |
| C | Average Irish home; moderate comfort and bills | |
| D | Rural home with oil heating; slightly less efficient | |
| E | Noticeably higher bills; good candidate for retrofit, expensive to heat; low comfort; upgrades recommended | |
| F | Poor energy performance; draughty | |
| G | Very high costs; full retrofit needed |
The BER is only an indication of a home’s energy performance.
How to boost your BER
Improving your BER will reduce your energy costs and make your home warmer and more comfortable.
The majority of homes in Ireland are C or D, but the higher your rating the more energy savings you can make.
Here’s some ways to boost your BER and save money on your energy bills and enhance the value of your house.
Case study: 3 bed family home, County Dublin
Like most BER-rated homes in Ireland, your home may have a C-rating, especially if it was built between 1980 and 2009.
- Gas is the main heating fuel used in a C-rated household
- Home heating oil is used more widely in C-rated homes
- C-rated homes may have some form of basic insulation
What can you do to boost the BER?
As up to 30% of all heat is lost through the attic, and 35% escapes through walls and doors, the main things that will improve your home’s BER rating are:
How much could it save you?
Taking steps to improve your BER could reduce your energy bills by over €1,000 every year.
What should you do next?
Contact a registered BER Assessor who will visit your property and carry out an assessment.
Once your home is assessed, you will receive an advisory report outlining the improvements needed to achieve a B rating.
What grants and financial help are available?
The SEAI offers a range of Home Energy Grants for homeowners and those undertaking a self-build. Home Energy Grants are available for the following:
| Upgrade type | Maximum grant |
|---|---|
| Wall insulation | Up to €8,000 |
| Attic insulation | Up to €2,000 |
| Windows and doors | Up to €4,000 |
| Heating controls | Up to €700 |
| Heat pump systems | Up to €12,500 |
| Solar PV panels | Up to €1,800 |
| Solar water heating | Up to €1,200 |
How can the SEAI One Stop Shop help?
The SEAI’s One Stop Shop is a wrap-around home energy upgrade service. It includes a home energy assessment, grant application, project management and any contractor work.
It’s a good option for homeowners who want multiple home energy upgrades without the hassle of managing a large project themselves.
What is the Home Energy Upgrade Loan Scheme?
It’s a government-backed initiative administered by the Strategic Banking Corporation of Ireland (SBCI) that offers homeowners unsecured, low-interest loans ranging from €5,000 to €75,000, with rates starting around 3% and flexible repayment terms of up to 10 years.
To qualify, your planned upgrades must be supported by an SEAI grant and be projected to improve your home’s Building Energy Rating (BER) by at least 20%.
Several Irish banks also offer Green personal loans and homeowner loans to improve your home’s energy efficiency. You’ll just need to provide evidence of the work and grants you’ve obtained to qualify for discounted loan rates.
Compare discounted Green loans
Green mortgages
Some Irish banks are offering discounted mortgage rates for homeowners with a good BER rating. They’re called Green mortgages and are worth considering if your home has a rating of B or better.
Bank of Ireland even offers an innovative fixed mortgage based on a building’s BER Rating, with discounts applied on a sliding scale: so the higher your BER, the larger the discount.
Find out more about Green mortgages and whether you could qualify for this type of mortgage from some of Ireland’s leading banks like Bank of Ireland in our helpful guide.
Estimated heating costs by BER rating
Most Irish homes fall into the C-rated or D-rated range, which means their annual energy costs can be materially higher than those of a newer A-rated home.
The table below shows illustrative annual energy costs by BER grade, benchmarked against a typical Irish dual-fuel household bill.
It is designed to show how costs rise and fall with a home’s energy efficiency, rather than predict a household’s exact annual bill.
BER ratings are based on standardised building energy performance, while actual bills will vary depending on occupancy, heating habits, tariff and home size.
| BER grade | Estimated annual cost* (€) | Compared with C-rated home | What it means in practice | |
|---|---|---|---|---|
| A0 | €361 | 89% lower | A zero-emission building, does not use fossil fuels, highest efficiency. | |
| A | €1,007 | 69% lower | Excellent efficiency; very low energy demand and annual energy costs. | |
| B | €1,936 | 40% lower | Efficient newer home; good efficiency, manageable energy bills, but room for improvement. | |
| C | €3,227 | Baseline | Benchmark used for a typical Irish dual-fuel home*, could benefit from energy upgrades. | |
| D | €4,303 | 33% higher | Common in older stock, more noticeable heat loss; clear upgrade and retrofit potential. | |
| E | €5,163 | 60% higher | High energy demand; expensive to run. | |
| F | €6,024 | 87% higher | Inefficient; retrofit strongly recommended. | |
| G | €8,175 | 153% higher | Extremely inefficient; very costly to heat. |
Based on an average annual Irish dual-fuel household bill, using standard unit rates correct as of April 2026.
Figures are illustrative and for comparison purposes only. Costs are modelled using BER band midpoints and benchmarked to a typical Irish annual dual-fuel bill.
They are designed to show the relative difference in energy costs between BER ratings, not predict a household’s exact annual bill. Actual costs vary by tariff, home size, heating system and usage.
Methodology
- We used the official BER rating bands published by the CSO, which measure a home’s energy performance in kWh/m²/year.
- To compare one BER rating with another, we used a midpoint for each band. The midpoint values used were: A0 = 21, A = 58.5, B = 112.5, C = 187.5, D = 250, E = 300, F = 350 and G = 475. These values were used to show the relative gap in energy performance between homes.
- We then used a C-rated home as the benchmark and anchored it to €3,227, based on our average annual Irish dual-fuel household bill benchmark using standard unit rates, correct as of April 2026.
- Other BER ratings were then scaled up or down from that C benchmark using this formula:
- Estimated annual cost = (BER midpoint ÷ 187.5) × €3,227
- This means homes with better BER ratings are shown with lower estimated annual costs, while less efficient homes are shown with higher estimated annual costs.
The figures are illustrative and intended to show how annual energy costs may rise or fall in line with BER performance. They are not a direct conversion of BER primary energy into an exact household bill.
Actual household energy costs will vary depending on tariff, home size, heating system, occupancy and usage patterns.
Sources:
BER FAQs
What is the new A0 category?
A0 is the new highest rating for homes that are highly energy‑efficient and do not use fossil fuels like heating oil or natural gas.
To qualify for an A0 rating, a home must be a true zero-emissions building. Even if a home is incredibly well-insulated, if it relies on a gas boiler, an oil heater, or even a stove that can burn fossil fuels, it will not qualify for an A0 rating.
How efficient is a C-rated home?
C-rated homes are most common in Ireland and are often used as a ‘typical example’ for residential property.
Gas is the main heating fuel used in a C-rated household (especially C1-rated homes), whereas home heating oil is more prevalent in C2 and C3-rated homes.
Although C-rated homes are more efficient than D to G-rated homes, they’re not as energy-efficient as A and B-rated homes.
As up to 30% of all heat is lost through the attic, and 35% escapes through walls and doors the main things that will improve your home’s BER rating include attic insulation, wall cavity insulation, and window and door upgrades.
Before carrying out any work, you should contact a registered BER Assessor who will visit your home and conduct an assessment. .
How much does it cost to upgrade to a better BER?
Costs depend on your home’s size and condition, but typical improvements, such as attic and wall insulation, boiler replacement, or new heating controls, range from €5,000 to €10,000 after SEAI grants.
Homes aiming for B or better may need additional measures such as external wall insulation, triple glazing, or renewable energy systems.
Which upgrades give the best BER improvement for the money?
The most cost-effective upgrades include:
- Attic insulation quick, affordable, and immediately beneficial.
- Wall insulation (cavity or external).
- Upgrading to a condensing boiler or heat pump.
- Adding heating controls to better manage energy use.
- Solar PV also helps by reducing grid electricity demand, improving your overall energy performance.
Can you sell a home with a low BER rating?
Yes. All homes for sale or rent in Ireland must have a BER certificate, but there’s currently no minimum legal rating.
However, a low BER (like D or lower) can make a property less appealing to buyers due to higher running costs and lower comfort levels.
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