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The Retrofit Readiness Checklist: Is Your Home a Good Candidate for Deep Retrofit?

Thinking about a deep retrofit for your home? Upgrading to modern insulation, heating, ventilation, and renewable energy can transform comfort, health, and running costs – but not every home is ready to dive straight in. Here’s how to assess if your property is a good candidate, and what steps to take first.

What Is a Deep Retrofit – and Why Does It Matter?

A “deep retrofit” means a whole-house upgrade: not just one improvement, but a coordinated package of insulation, airtightness, new heating (like a heat pump), ventilation, and often renewable energy (like solar PV). The goal is to dramatically cut energy use, improve comfort, and boost your BER (Building Energy Rating), often taking a G- or F-rated home up to a B or even A rating.

Why bother? Because deep retrofits can:

  • Slash your heating bills by up to 50-70% (SEAI)
  • Make your home warmer, healthier, and free of draughts or cold spots
  • Add value and future-proof your property against energy price rises and stricter standards

But every home is unique – so how do you know if yours is ready?

1. Age and Construction Type Considerations

Older homes (pre-1980s) often have poor insulation and single glazing, making them strong retrofit candidates. For example:

  • 1940s-1970s bungalows and semis: Usually cavity wall, minimal attic insulation, single glazing – big potential for improvement.
  • Rural stone cottages: Solid walls, often damp or poorly ventilated; need specialist solutions but can see huge gains.
  • 1990s-2000s homes: May have some insulation, but often not to modern standards.
  • Post-2006 homes: Usually already well insulated; deep retrofit may not be needed.

Key questions:

  • When was your home built?
  • Is it cavity wall, solid wall, or stone construction?
  • What insulation and glazing do you currently have?

2. Structural Requirements & Pre-Retrofit Repairs

A deep retrofit is only as good as the structure it’s built on. Before you start, check for:

  • Damp, leaks, or water ingress: Look for patches on ceilings, walls, or floors.
  • Structural cracks or subsidence: Cracks wider than a €2 coin, doors/windows sticking, sloping floors.
  • Poor roof condition: Missing tiles, sagging timbers, moss growth.
  • Rotting timbers or window frames: Soft wood, flaking paint, visible mould.

Why it matters: Insulating over damp or unstable structures can trap moisture, worsen problems, and shorten the life of your investment. Always fix these issues first – even if it means delaying your retrofit.

3. Budget Planning & Grant Eligibility Factors

Deep retrofits are a significant investment. In Ireland, the SEAI’s One Stop Shop grant can cover up to 45% of the cost for eligible homes, but you’ll need to budget for your contribution.

Typical cost range: €30,000-€70,000+ for a deep retrofit (SEAI, 2024).

Sample breakdown:

  • Insulation (walls, attic, floors): 40-50%
  • Windows/doors: 10-15%
  • Heating/controls/ventilation: 25-30%
  • Solar PV: 5-10%
  • Project management, BER, and contingencies: 10-15%

Grant eligibility basics:

  • Your home must be built before 2011
  • You must complete a “whole house” upgrade (insulation, windows, heating, ventilation)
  • The project must be managed by an SEAI-registered One Stop Shop (like Leetherm)

See SEAI’s full eligibility criteria »

Payback & Added Value:

While payback depends on your starting point, most homeowners see a significant reduction in bills and an increase in property value. Plus, a higher BER makes your home more attractive to future buyers.

4. Timelines & What to Expect

Retrofit timelines depend on:

  • Home size and complexity
  • Scope of works (full upgrade vs phased)
  • Pre-existing issues (repairs, asbestos, planning)

Typical timeline: 3-6 months from assessment to completion, but this can vary.

What to expect:

  • Initial assessment and BER survey
  • Design and grant application
  • Pre-works repairs (if needed)
  • Main retrofit works (may involve moving out of key rooms, dust, and noise)
  • Final inspections and grant paperwork

Older, more complex homes may take longer due to unforeseen repairs or specialist works. Most people can live at home during the works, but expect some disruption.

5. Red Flags That Need Addressing First

Some issues must be sorted before a retrofit can begin:

  • Active leaks or rising damp (must be fixed to prevent trapped moisture)
  • Structural instability (can make works dangerous or ineffective)
  • Asbestos (requires specialist removal – never DIY)
  • Planning restrictions (for protected structures or conservation areas)
  • Unresolved legal or access issues (shared walls, right of way)

Ignoring these can lead to failed upgrades, wasted money, or even health risks. For example, insulating over damp can cause rot and mould, and skipping planning can mean costly legal trouble later.

6. Best and Worst Candidates for Deep Retrofit

Best candidates:

  • Homes built pre-2006, especially with poor insulation and heating
  • Owners planning to stay long-term (5+ years)
  • Properties with clear access for works
  • Homeowners ready for short-term disruption for long-term gain

Worst candidates:

  • Recently built homes (already energy efficient)
  • Properties with major unresolved structural issues
  • Homes where planning or legal barriers exist
  • Owners seeking “quick fixes” or minimal disruption

Quick self-checklist:

  •  My home is older than 2011
  •  I’m ready to invest and stay long-term
  •  I’ve checked for damp, leaks, or structural problems
  •  I’m open to a few months of disruption for lasting benefits

Retrofit FAQs

Can I do a deep retrofit in stages?

Yes, but you’ll need to plan carefully to maximise efficiency and grant eligibility. The SEAI’s One Stop Shop model is designed for whole-house upgrades, but phased works are possible – ask your provider for advice.

What if my home is listed or in a conservation area?

Special rules apply – get advice early, and check with your local authority. Some measures may need planning permission.

Can I stay in my home during the works?

Usually yes, but expect some rooms to be out of action. Your contractor will advise on what’s practical.

Why Homeowners Choose Leetherm (In Their Words)

When you’re investing in a home energy upgrade, expertise matters – especially when it comes to navigating the SEAI One Stop Shop process. At Leetherm, our friendly experts manage the journey end-to-end: clear advice, quality workmanship, and the reassurance that the grant paperwork is handled properly as part of the service. And because we’ve supported homeowners across the region through upgrades with minimal stress and disruption, we know what “good” looks like – not just on paper, but in the day-to-day experience of living through the works.

What homeowners say about Leetherm’s retrofit service:

Leetherm were very accommodating to our needs, excellent work and cleaned up after works completed you would never even know the workers were there.

Clare – Carlow

The surveyors were very informative and helpful, workers were very courteous, excellent work, house was spotless, the lady in the office was so helpful and friendly, couldn’t ask for more. So wonderful that all the grant work is completed by Leetherm, thanks to everyone.

Nicola – Cashel, Tipperary

All works were done with minimal disruption. All were extremely helpful throughout the process. There was no question left unanswered. House was left clean and tidy. Everything was explained to us and recommended ways to use the systems installed. Once the process was started it ran like clockwork. Would 100% recommend Leetherm. Could not be more satisfied and happy.

Liam – Callan, Kilkenny

Ready to Check Your Retrofit Readiness?

A deep retrofit is a big step, but it can deliver huge improvements in comfort, health, and running costs. 

Leetherm is a SEAI-registered One Stop Shop, which means we are fully up to date on the latest grants and supports available to help homeowners offset the cost of home energy upgrades. We manage the process end-to-end – from assessment and planning through to project delivery and grant administration – so you can move forward with confidence and clarity. And we’ve helped hundreds of homeowners just like you create a healthier, cosier, more energy-efficient home, with upgrades that are prioritised properly and built to last. 

Get in touch today by filling out our enquiry form, and one of our local energy experts will be in touch to talk through your home, your goals, and the best next step.