Identifying ‘fabric first’ wins for large-scale council retrofit
Background
Value Optimised Retrofit (VOR) is among the most experienced and well-respected retrofit specialists in the country. We have partnered with them on many projects where building testing services are required as part of the retrofit process.
One of the first large-scale projects we supported them on was for Unitas, Stoke on Trent – a local authority successfully rolling out retrofit projects following the PAS 2035 framework.
The Challenge
Stoke-on-Trent’s housing stock, like many other councils across the country, contains post-war modular housing built in a hurry during the economic boom of the 1950s. Value Optimised Retrofit were commissioned to coordinate the retrofit of 80 properties where residents were struggling with rising energy bills and cold, damp, draughty living conditions. Upgrading the building fabric and installing adequate ventilation could both improve the lives of residents and reduce the carbon footprint of each dwelling.
While most of the houses looked the same, VOR identified 13 different archetypes, based on their differences in layout and build. Each of these had to be fully tested for air tightness and adequate ventilation, while some required thermography to better understand the performance of the building fabric.
Specialist building testing expertise lies outside the skillset of a standard retrofit assessor, so VOR needed to bring in this specialism to ensure the success of the project. This is where we come in.
The Solution
Luckily, our team is cross-trained and qualified in both retrofit and testing. We brought the following building testing and retrofit specialist services to the project:
Combining our ability to carry out retrofit assessments at scale with our background in testing saved the project time, money, and other resources.
Retrofit Assessment Observations
While many of the houses had received upgrades (like double-glazing) in the past, they were still cold, leaky, and inefficient. Some of the most common observations we encountered while carrying out assessments included:
- Paper-thin walls (100 – 120 mm)
- Insulation inadequate or lacking entirely in the roof space
- Out-of-date boilers
- Poorly installed, first-generation double-glazing (6 mm)
- Electric fires that had replaced gas fires to reduce carbon emissions – but at a cost to residents because electricity costs more
- Incorrect EPCs that didn’t reflect the real energy performance, and therefore undervalued the true cost of energy to each resident.
The buildings were ultimately very bad at retaining heat because they had thin walls, poorly installed windows, and virtually no insulation.
Retrofit Coordinator Recommendations
Following on from the observations made by our assessment team, VOR recommended that external wall insulation would need to be added along with upgraded windows and doors and improved ventilation. Taking this ‘fabric-first’ approach gives residents immediate relief from expensive energy bills and cold homes, while reducing the heating requirements needed from any future renewable heating system installed.
VOR do a great job of explaining the importance of taking a fabric-first approach here:
Final outcomes
Overall we conducted retrofit assessments and testing on 80 buildings over eight weeks, collaborating with VOR’s coordinators to produce some of the most comprehensive assessment reports in the UK.
We ultimately saved the project time, money, and effort by undertaking both testing and assessment in a single visit to each property.
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
