If your home feels freezing again shortly after the heating goes off, you could be paying to heat the outdoors.
SEAI states that a home can lose up to 30% of its heat through poorly insulated roofs and walls, with further heat escaping through inefficient windows, doors and uninsulated floors. Improving your insulation keeps more warmth inside, reduces energy waste and can help improve your home's Building Energy Rating.
Why Insulate Your Home?
Attic insulation is often one of the most cost-effective energy upgrades an Irish homeowner can make. Depending on the property, other options may include:
- Attic or rafter insulation
- Cavity-wall insulation
- Internal dry lining
- External wall insulation, often called “the wrap”
- Floor insulation
- Energy-efficient windows and doors
The main benefits include a warmer and more comfortable home, lower energy use, fewer draughts, more even room temperatures, reduced carbon emissions and an improved BER.
Take a Fabric-First Approach
SEAI recommends starting with the building fabric. In practical terms, that means reducing heat loss through the attic, walls, floors, windows and doors before moving on to major heating or renewable-energy upgrades.
Once your home holds heat more effectively, you can consider measures such as heating controls, a correctly designed heat pump or solar PV. A well-insulated home is also better suited to a heat pump because less energy is needed to replace escaping heat.
Plan the retrofit properly
Insulate first. Then improve the system.
Start with heat loss and building fabric, then consider heating controls, ventilation and renewable technologies that suit the finished home.
Do Not Forget Ventilation
Insulation and airtightness should never be considered without proper ventilation. SEAI notes that a well-insulated home is warmer and more airtight, which makes good ventilation important for both the building and its occupants.
Good ventilation helps remove stale air, excess moisture and pollutants, and can reduce the risk of persistent condensation and mould. Never permanently block existing vents without professional advice.
How Does Retrofitting Improve Your BER?
A BER measures the energy performance of your home. New BER certificates issued from 24 May 2026 use Ireland's simplified A0-to-G scale, with A0 representing the most energy-efficient buildings that do not use fossil fuels. Existing BER certificates issued under the previous scale remain valid for their normal validity period.
Insulation can improve your BER by reducing the amount of energy required to heat the property. A deeper retrofit may combine insulation with ventilation, efficient heating, upgraded controls, windows, doors and renewable-energy technology.
For a complete explanation, read our BER ratings in Ireland and how to improve your home's rating guide.
Check SEAI Grants Before Work Begins
SEAI currently offers individual grants for qualifying measures including attic insulation, wall insulation, windows and doors, heating controls and heat-pump systems. Grant values and eligibility depend on the measure, property and scheme being used.
Grant approval must be in place before grant-supported work begins, and the work must be completed by an SEAI-registered contractor for the relevant measure where required. Always confirm current values, eligibility and contractor requirements directly with SEAI before committing to the work.
Find Insulation Contractors with Trade Source IRE
Trade Source IRE helps homeowners, landlords and businesses submit enquiries for attic, wall, cavity, floor and wider home-energy upgrade projects across Ireland.
Tell us your property type, location, current insulation, areas requiring work and preferred timeframe. We will review your enquiry and help route it to potentially suitable professionals where available.
- Find insulation contractors across Ireland
- Read our SEAI Grants Ireland 2026 guide
- Learn how to improve your BER rating
- Submit your home-energy upgrade project
For grant-supported work, independently confirm that the chosen contractor is currently registered with SEAI for the exact upgrade being completed. You should also compare written quotations and check insurance, experience, materials, ventilation requirements and guarantees before work begins.
Stop letting valuable heat escape. Insulate first, retrofit properly and make your home warmer, more comfortable and ready for the future.
Every Trade. One Trusted Source.
Official Irish information sources
Important note
This article provides general information. The most suitable insulation, ventilation and retrofit measures depend on the age, construction and condition of the individual property. Grant rules and values can change, so confirm current requirements directly with SEAI before starting work.