CASE STUDY

From Defective Concrete Blocks to an A0 Home

A detached home in Buncrana, Co. Donegal, approved for remediation under the Defective Concrete Blocks scheme, was rebuilt and upgraded from a C2 to an A0 BER, with REIL managing the energy upgrade and SEAI grants.

€28,900 SEAI Grant Secured

Full Project Management

A0 Zero Emission Building

BEFORE

C2

176.33 kWh/m²/yr

43.9 kgCO₂/m²/yr

AFTER

A0

33.75 kWh/m²/yr

3.79 kgCO₂/m²/yr

142.58 kWh/m²/yr

improvement in energy performance

A0

New BER Rating

C2

Previous BER Rating

€28,900

SEAI Grant Secured

€375,000

DCB Remediation Grant

91%

Reduction in Calculated Carbon Emissions

7 Energy Upgrade Measures

181.92m²

Floor Area

40.11 kgCO₂/m²/yr Improvement

THE STORY

Rebuilding a Home, and Making It A0

Susan O’Brien’s detached home in Buncrana, Co. Donegal was built in 2004, and she moved in in 2006. Five years later, in 2011, she noticed cracking in the blocks. She applied for the Defective Concrete Blocks scheme in early 2023, and her home was approved for remediation.

In 2024, the Government announced that energy upgrade grants would be available as part of the enhanced redress scheme. Susan decided to make the most of the rebuild and wanted it to deliver real energy efficiency, not just a like-for-like repair.

REIL managed the energy upgrade alongside the rebuild, working with T&D Doherty Construction and architects North West Modern Designs so the design, build and grant process moved together. The package covered insulation, windows and doors, a heat pump with central heating, and mechanical ventilation. The home had previously been heated with oil and a solid fuel stove.

The result is an A0 BER, the highest rating available, with an energy value of 33.75 kWh/m²/yr, down from 176.33. The home is rated a Zero Emission Building, and calculated carbon emissions have fallen by over 90%.

REIL handled the SEAI grant process from start to finish and deducted the grants upfront, so Susan never had to pay for the upgrade in advance.

Why this project stands out

BER improved from C2 to A0
Energy value improved by 142.58 kWh/m²/yr
Rated a Zero Emission Building
€28,900 SEAI energy grant alongside the €375,000 DCB remediation grant
Oil and solid fuel heating replaced by a heat pump
Calculated carbon emissions down by over 90%

THE PERFORMANCE UPLIFT

From Defective Blocks to A0: A Home Rebuilt

253.46 kWh/m²/yr Improvement

A home rebuilt after defective concrete blocks, now rated A0 and cutting calculated carbon emissions by over 90%.

A Whole-Home Upgrade Alongside the Rebuild

REIL coordinated the energy measures with the rebuild across the building fabric, heating, ventilation and grant management.

SCHEDULE OF WORKS

▦

Wall Insulation

Cavity wall insulation cuts heat loss through the external walls, one of the main sources of energy waste in any home.

⌂

Roof & Floor Insulation

Insulation at ceiling level and under the ground floor stops heat escaping, tightening the thermal envelope alongside the walls.

▣

Windows & Doors

New high-performance windows and two external doors reduce heat loss, eliminate draughts and improve comfort throughout.

▥

Air-to-Water Heat Pump & Central Heating

A new 8kW heat pump and central heating system provide space heating and hot water, with no fossil fuels used on site.

◎

Mechanical Ventilation (MVHR)

A balanced whole-house ventilation system with heat recovery keeps the air fresh and manages moisture in the new, well-insulated home.

✓

Renewable Heat Bonus & Project Management

REIL managed the project from first assessment through to final BER and grant processing, including the SEAI Renewable Heat Bonus, coordinating with the builder and architect throughout.

PROJECT GALLERY

A3-Rated and Gas-Free: Inside the Buncrana Retrofit

The original home DCB affected (before)

The rebuild underway

Built for Efficiency from the Start

After: rebuilt and rated A0

A bright, comfortable home

Air Source Heat Pump systems

REAL-WORLD IMPACT

The Numbers That Matter

Before the rebuild, Susan estimates she spent around €370 a month on energy, about €120 on electricity and about €250 on heating oil, coal and wood.

Fossil fuel costs have been eliminated entirely following the heat pump installation

€

~€1,330 a year

This is the projected yearly electricity cost of heating and powering a rebuilt, A0-rated home, with no oil, coal or wood.

Electricity before:

~€120

a month

Heating fuel, before:

~€250

a month

Combined energy before:

~€370

a month

Projected Annual Cost

~€1,330

after upgrade

CLIENT REVIEW

★★★★★

I wanted the rebuild to deliver real energy efficiency. REIL’s team worked hand in hand with my architect and builder to plan it properly, and I never had to pay a cent upfront – the result speaks for itself

T

Susan O’Brien,

Buncrana, Co. Donegal

CONCLUSION

What This Project Demonstrates

This project shows what’s possible when an energy upgrade is planned into a defective concrete blocks rebuild from the start, rather than added later. A home affected by DCB has been rebuilt and upgraded from C2 to A0, with calculated carbon emissions down by over 90%.

With REIL managing the SEAI grants and coordinating with the builder and architect, Susan has a warm, comfortable, energy-efficient home, and she didn’t have to pay for the upgrade upfront.

HOW REIL MAKES IT SIMPLE

One Managed Process, Alongside Your Rebuild

Susan didn’t have to manage the SEAI paperwork or the grant process herself. REIL worked alongside her builder and architect from first assessment to final BER.