Easiform Housing Project, Bristol

Cavity Wall Insulation

INTRODUCTION


A £382,000 energy efficiency retrofit project completed in May 2023 for 61 residential properties in the Henbury & Brentry Ward of Bristol. This pilot scheme aimed to decarbonise concrete houses suffering from excessive cold, condensation and damp issues that were creating mould hazardous to residents' health. The project, funded by SHDF and commissioned by Bristol County Council, focused on cavity wall insulation and ventilation improvements to enhance thermal efficiency and indoor air quality.

Project Challenges & Solutions

Technical Challenges

Easiform homes lacked existing British Board of Agrément (BBA) certification for cavity wall insulation, creating

significant technical hurdles. These concrete slab constructions, built

by John Laing in 1919, were highly susceptible to cold bridging and damp

issues.

Innovative Approach

TF Energy & ARP partnered with Instagroup & BBA to develop an

approved cavity wall insulation method. The solution involved blown eco EPS beads injected into cavities at strategic

patterns, combined with a

comprehensive ventilation strategy.

Resident Considerations

Working in occupied homes required careful scheduling and proactive

communication. Resident Liaison Officers engaged directly with tenants,

providing updates and addressing concerns through a phased work approach.

The project team used three pilot properties to test and refine their approach, conducting rigorous assessments on insulation performance, ventilation impacts, and structural integrity. This methodical process ultimately secured BBA certification, setting a new industry benchmark for future Easiform

retrofits.

Ventilation Strategy


A bespoke ventilation strategy was designed to complement the insulation work, integrating passive vents and mechanical extraction to ensure proper airflow throughout the properties. This approach was critical to prevent moisture build-up that could otherwise

worsen following insulation installation.

Insulation Approach


Breathable, moisture-resistant insulation was carefully installed to maintain long-term durability. The team filled the cavities of the

concrete slab construction with cavity wall insulation, with External Wall Insulation (EWI) scheduled for a later phase of the project.

The successful completion of this project has delivered significant improvements in thermal comfort and energy efficiency for residents while establishing a proven methodology for similar Easiform properties across the UK. Post-installation surveys gathered valuable feedback that will help refine future delivery approaches for this challenging housing type.

Outcomes & Conclusion

Safe Execution

Project completed with zero safety incidents despite complex working

conditions and tight timeframes.

On-Time Delivery

All installation phases completed within allocated half-term windows, preventing any disruption to school operations.

Quality Installation

High-performance Accoya timber windows and doors installed to the

highest standard, improving both aesthetics and energy efficiency.

The project demonstrates TF Energy's ability to deliver complex installations in sensitive environments with strict scheduling constraints. Through careful phasing, strict asbestos management protocols, and efficient scaffold logistics, the team ensured a controlled installation programme that maintained a safe environment for staff and pupils throughout.


Brookfield Primary School now benefits from high-performance windows and doors that comply with conservation requirements while significantly improving the building's energy efficiency, comfort, and security.