
Improving energy efficiency while safeguarding occupant well-being.
This case study focuses on a retirement housing development managed by Anchor, England’s largest provider of specialist housing and care for older people. The development consists of 28 retirement flats, with the project aiming to improve energy efficiency using funding from the Social Housing Decarbonisation Fund (now the Warm Homes: Social Housing Fund) Wave 2.1. We were commissioned to assess these properties by Value Optimised Retrofit (VOR), Retrofit Designers and Coordinators, who were commissioned by Wates, the primary contractor.
The Challenge
The project sought to address multiple challenges related to energy efficiency, energy demand, damp and mould, and energy costs. The intended specific outcomes were:
- Achieve an EPC rating of C for all properties
- Achieve below 90kWh heat demand for all properties
- Reduce energy bills
- Resolve any reported issues of damp and mould
The Solution: What was undertaken?
In Newbury between the 20th of May and the 3rd of June 2024, we conducted PAS 2035-compliant retrofit assessments and testing to deliver a comprehensive view of building performance. Key actions included:
- PAS 2035 compliant retrofit assessments were completed for all 28 flats
- Pulse air tightness testing was carried out on all properties
- Part F Ventilation Testing for all flats, assessing ventilation flow rates, trickle vents, and purge ventilation using calibrated anemometers and balometers
- Intrusive borescope surveys were conducted on properties where damp was reported to identify water ingress sources and insulation conditions
- Identified 4 archetypes across the development to streamline the assessment and testing process
Before our initial visit, we carried out a brief archetype survey of the properties, categorising key characteristics to streamline assessments and increase on-site efficiency. Selected properties underwent more comprehensive testing, including blower door air tightness tests.
This project was a great opportunity to demonstrate the value of comprehensive assessments. Identifying archetypes early on allowed us to streamline the process, and the borescope surveys gave insight into any underlying damp issues whilst providing clarity to current insulation conditions
Oliver Morgan, Retrofit Manager at Building Energy Experts
Key Observations from our Retrofit Assessors
- Top-floor flats achieved EPC C ratings, largely due to previously applied external wall insulation (EWI).
- The properties were not connected to mains gas, so the flats rely on relatively efficient electric storage heaters.
- Borescope surveys showed evidence of filled cavity walls with no observable causes for damp problems.
- Generally the ventilation was not sufficient, with inadequate ventilation determined as the underlying cause of damp issues in certain flats.
The Results
Our comprehensive assessments provided actionable data that helped the project’s design team recommend targeted solutions. Our insights included:
- Identified ventilation issues as the primary cause of damp, enabling VOR’s designers to specify appropriate solutions.
- Delivered actionable data for EPC improvements and heat demand reductions.
- Equipped project stakeholders with a comprehensive understanding of building performance, ensuring a solid foundation for future retrofit work.
Lessons Learned
The key lesson here is that ventilation is critical to prevent damp and mould, particularly in older buildings. Inadequate ventilation was found to be the main contributor to damp issues in several flats, highlighting the importance of airflow alongside insulation and airtightness in retrofit projects.
Strong collaboration between housing providers, contractors and specialists is critical for project success. In this case, effective collaboration with VOR, Wates, and Anchor was key to overcoming challenges and achieving the project’s goals.
An integrated approach addressing all building performance aspects – ventilation, insulation, heating and air tightness – is essential for ensuring long-term benefits for occupants.
What’s Next?
This project has reinforced the value of detailed assessments and collaborative partnerships in delivering successful retrofits. If you’re managing a large-scale retrofit project, we can help you achieve compliance, improve energy efficiency, and ensure long-term success.