Delivering combined retrofit assessment and specialist testing in a single site visit across 80 post-war council homes, cutting programme time without cutting technical rigour.
Project Overview
- Client: Value Optimised Retrofit (commissioned on behalf of Wates and Unitas)
- Sector: Social Housing & Housing Associations | Local Authority-Led Programmes
- Location: Stoke-on-Trent, Staffordshire
- Services Provided: PAS 2035 Retrofit Assessments, Air Tightness Testing, Ventilation Testing, Thermography
- Scale: 80 properties across 13 building archetypes
- Target: PAS 2035-compliant retrofit of post-war modular housing
The Challenge
Stoke-on-Trent’s housing stock includes a large amount of post-war modular housing, built quickly during the 1950s economic boom – the kind of stock many councils across the country are now grappling with. Unitas’s residents were living with rising energy bills and cold, damp, draughty homes across 80 such properties earmarked for retrofit. Although most of the houses looked similar from the outside, they actually fell into 13 distinct archetypes based on differences in layout and build, each needing its own air tightness and ventilation testing, with some requiring thermography to properly understand how the building fabric was performing. Delivering a retrofit that would genuinely work for residents meant getting specialist testing expertise involved from the outset – something that sits outside a standard retrofit assessor’s skillset.
The Solution
Integrated PAS 2035 Retrofit Assessment & Building Testing
Being cross-trained in both retrofit assessment and specialist testing let our assessors bring retrofit assessments, air tightness testing, ventilation testing, and thermography to the project as a single, combined service rather than coordinating multiple separate visits. Across the 80 properties, common issues emerged clearly: walls as thin as 100–120mm, roof insulation that was inadequate or missing entirely, ageing boilers, poorly installed first-generation double-glazing, and electric fires that had replaced gas fires to cut emissions – but pushed up costs for residents in the process, since electricity is more expensive per unit. We also found EPCs that didn’t reflect the properties’ real energy performance, understating the true cost of energy each resident was actually facing. Together, thin walls, poor windows, and minimal insulation meant these homes were simply very bad at holding onto heat, regardless of what “upgrades” they’d already had.
Based on these findings, the retrofit strategy centred on a fabric-first approach – external wall insulation, upgraded windows and doors, and improved ventilation – giving residents immediate relief from high energy bills and cold homes, while also reducing the heating demand that any future renewable heating system would need to meet.
The Outcome
We completed retrofit assessments and testing across all 80 properties in eight weeks, working alongside the project coordinators to produce what became some of the most comprehensive retrofit assessment reports in the UK. Carrying out both the assessment and the technical testing in a single visit to each property saved the project meaningful time, cost and resource compared to running them as separate exercises – a real advantage on a programme of this scale.
Client Testimonial
At Value Optimised Retrofit we pride ourselves on excellence at every stage of the process, ensuring compliance to the highest level. This is why we choose to work closely with Building Energy Experts on our projects.
The information collected during the assessment is vital to enable us to produce accurate energy modelling, planning of retrofit measures, and to ensure robust design that will help to deliver the net zero targets of our clients. Building Energy Experts always deliver the highest quality information.
— Kelly Brown, Project Director, Value Optimised Retrofit
