Home Insulation Quotes in Ireland
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Most Irish homes built before 2006 have poor insulation by today's standards, and many built before 1990 have almost none. If your house feels cold even with the heating running, if you can feel draughts around windows and doors, or if your annual heating bill is pushing past €2,000, the problem is almost certainly heat loss through your walls, roof, or floor. Insulation is the single most cost-effective energy upgrade you can make.
The right type of insulation depends entirely on your home. A 1970s cavity-block semi-detached in a Dublin housing estate is a straightforward cavity fill job, usually completed in half a day with no disruption inside the house. A solid-wall cottage in rural Kerry needs external or internal insulation, a completely different project in terms of cost, disruption, and finish. A 1990s detached house might only need its attic topped up from 100mm to 300mm to make a noticeable difference.
SEAI grants cover a large portion of insulation costs for qualifying homeowners. Attic insulation grants are up to €1,500, cavity wall grants up to €1,700, and external wall insulation grants up to €6,000. Under the National Home Energy Upgrade Scheme, some households can get up to 80% of costs covered. But not every contractor is SEAI-registered for grant work, and the quality of installation varies significantly between companies.
Poorly installed insulation can cause condensation, mould, and even structural damp. This is not a job where the cheapest quote is necessarily the best value. Comparing three or more quotes from registered contractors protects your home and your wallet.
SEAI Grants May Be Available
Some home insulation work may qualify for SEAI grants. Visit HomeEnergyGuide.ie to check eligibility and amounts.
SEAI Grants May Apply
Some home insulation work qualifies for SEAI grants of up to €8,000 or more. Check eligibility and current grant amounts on our energy guide.
Check SEAI Grants on HomeEnergyGuide.ieHow Much Does Home Insulation Cost in Ireland?
Typical pricing for home insulation services in Ireland (2026):
| Service | Typical Cost | Notes |
|---|---|---|
| Attic insulation (semi-detached) | €800 | €1,500 | Area, depth, access |
| Cavity wall insulation | €1,200 | €2,000 | Wall area, access |
| External wall insulation | €8,000 | €18,000 | Size, finish type |
| Internal dry lining | €4,000 | €8,000 | Rooms, access |
Insulation costs vary most based on three factors: the type of insulation needed (cavity fill is cheap, external insulation is expensive), the size of your home, and access. A bungalow with easy attic access costs less to insulate than a two-storey with a converted attic. External insulation on a semi-detached is roughly half the cost of a detached because you only have three exposed walls. Dublin contractors typically charge 10-15% more than the national average, while rural areas may carry a small travel surcharge.
What to Expect: The Home Insulation Process
- A registered contractor visits your home to assess what insulation you currently have, what type is needed, and to take measurements. They check your wall construction (cavity or solid), existing insulation depth, ventilation, and any damp issues.
- You receive a written, itemised quote specifying the insulation type, thickness, area to be covered, estimated BER improvement, and whether the work qualifies for SEAI grants.
- If applying for an SEAI grant, the contractor submits the application on your behalf before work begins. You must not start work before receiving grant approval.
- Installation. Cavity wall insulation takes 4 to 6 hours. Attic insulation takes a day. External wall insulation takes 2 to 4 weeks depending on house size. Internal dry-lining takes 1 to 2 weeks per room.
- After installation, the contractor provides a Declaration of Works and any compliance certificates. For grant-eligible work, SEAI may carry out a post-works inspection.
- You can then get a new BER assessment to reflect the upgraded insulation, which is advisable if you plan to sell or rent.
Common Mistakes to Avoid
- Insulating without addressing ventilation. This is the most common and most damaging mistake. Sealing up a draughty house without providing controlled ventilation traps moisture and causes mould. Always discuss ventilation with your contractor.
- Choosing a contractor based purely on the lowest quote. Insulation quality depends on correct installation. Gaps, compression, and poor detailing around windows and doors all reduce performance. A contractor who quotes 30% less may be cutting corners.
- Not checking SEAI registration before work starts. If your contractor is not registered, you cannot claim the grant, and you have no recourse through the SEAI complaints process if something goes wrong.
- Insulating over existing damp problems. If you have rising damp, penetrating damp, or a leaking roof, these must be fixed first. Insulating over damp traps moisture and makes the problem far worse.
- Skipping the attic. Because it is out of sight, many homeowners focus on walls first. But attic insulation is the cheapest, quickest, and most impactful upgrade for most Irish homes. Always start at the top.
What to Look for When Hiring a Home Insulation Professional
Your insulation contractor must be SEAI-registered if you want to claim grants. Check the SEAI contractor register at seai.ie. For cavity wall work, look for contractors certified under the NSAI Agrement scheme (National Standards Authority of Ireland), which ensures the insulation material and installation method meet Irish standards. For external insulation, the contractor should be C2-registered, meaning they have completed NSAI-certified training. Ensure they carry public liability insurance (minimum €2 million) and employer's liability insurance. Be wary of contractors who cannot show you a current SEAI registration number, who ask for full payment upfront, or who do not mention ventilation. Insulation changes how your home breathes, and failing to address ventilation can cause serious condensation and mould problems.
Questions to Ask Your Home Insulation Professional
- Are you SEAI-registered for this type of insulation work? SEAI registration is required for grant eligibility. Registration is specific to insulation types, so a contractor registered for cavity fill may not be registered for external insulation.
- What type of insulation do you recommend for my home and why? A good contractor will explain why they are recommending a specific material and method based on your wall construction, not just default to the cheapest option.
- Will this work qualify for an SEAI grant, and will you handle the application? Most SEAI-registered contractors handle the grant paperwork. If they cannot or will not, that is a red flag.
- How will you address ventilation after insulating? Insulation makes your home more airtight. Without adequate ventilation, moisture builds up and causes condensation and mould. A responsible contractor raises this proactively.
- Can you provide references from similar jobs in my area? Insulation on a 1970s semi is a different job to a period stone cottage. You want a contractor who has successfully completed work on homes like yours.
- What guarantee or warranty do you provide? Reputable contractors offer a minimum 10-year workmanship guarantee. NSAI-certified cavity fill carries an independent product guarantee. If the contractor offers no guarantee, walk away.
- Do I need to move out during the work? Cavity fill and attic insulation cause minimal disruption. External insulation means scaffolding and noise for weeks. Internal dry-lining means losing a room at a time. Knowing the disruption level upfront helps you plan.
Frequently Asked Questions
Attic insulation for a standard three-bedroom semi-detached house typically costs €800 to €1,500, depending on the area to be covered, the depth of insulation required (300mm is the current standard), and how easy it is to access. If your attic is already partially insulated, a top-up to 300mm costs less. The SEAI grant of up to €1,500 can cover a significant portion of this cost, making attic insulation one of the best-value energy upgrades available.
SEAI currently offers: up to €1,500 for attic insulation, up to €1,700 for cavity wall insulation, up to €6,000 for external wall insulation, and grants for internal dry-lining. These are individual measure grants available to all homeowners. Under the National Home Energy Upgrade Scheme, households with lower incomes can receive up to 80% of total costs. Your home must have been built before 2011, and the work must be done by an SEAI-registered contractor.
Possibly. Homes built between 1990 and 2005 typically have cavity walls with partial fill (50-75mm), which falls short of current standards (150mm+). Topping up the attic insulation from 100mm to 300mm is almost always worthwhile and costs very little. Whether cavity or wall upgrades make sense depends on what is already there. A BER assessment will tell you exactly where your heat is escaping and which upgrades deliver the best return.
Cavity wall insulation fills the gap between the two layers of your external walls with pumped beads or bonded bead material. It is quick (half a day), cheap (€1,200 to €2,000), and invisible once done. External wall insulation wraps your house in rigid insulation boards finished with a render coat. It is far more expensive (€8,000 to €18,000) and takes several weeks, but it eliminates cold bridges and transforms the look of your home. Your wall construction determines which option is possible.
Quality insulation materials last 40 to 50 years or more. Mineral wool in the attic, expanded polystyrene on external walls, and pumped bead in cavities all have excellent longevity. The main risk to lifespan is water damage. If your roof leaks into the attic or rising damp affects wall insulation, the material can degrade. Ensuring your home is weathertight before insulating protects your investment.
External wall insulation is generally exempt from planning permission under Irish exempted development rules. However, there are exceptions: if your home is a protected structure, in an Architectural Conservation Area, is an apartment or duplex, or if the insulation changes the building line or exceeds certain thicknesses. If you live in a semi-detached or terraced house, your neighbour's consent is not required, but the finish must be sympathetic. Your contractor or local authority can confirm whether your project needs permission.
Poorly installed insulation can cause condensation if ventilation is not addressed at the same time. When you insulate, your home becomes more airtight, trapping moisture from cooking, showering, and breathing. Without adequate ventilation (through vents, extractors, or an MVHR system), this moisture condenses on cold surfaces and leads to mould. A responsible contractor will always assess your ventilation needs as part of the insulation job.
Always insulate first. Heat pumps work most efficiently in well-insulated homes because they operate at lower water temperatures than boilers. If your home is poorly insulated, a heat pump has to work harder, costs more to run, and may not keep your rooms warm enough. Most SEAI One Stop Shops will recommend a fabric-first approach: insulation and windows first, then the heating system.
The savings depend on your starting point. A home with no attic insulation that gets 300mm installed can see heating bills drop by 20-25%. Adding cavity wall insulation on top of that delivers another 15-20% reduction. A full external insulation job on a solid-wall home can cut heating costs by 30-40%. These figures assume your heating system is working efficiently. If your boiler is also old, upgrading both insulation and heating together delivers the biggest savings.
Home Insulation Quotes by County
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