
Our team of experienced retrofit assessment professionals has completed thousands of domestic assessments, developing best practices that ensure efficient, thorough assessments. We are adaptable, reliable, and ready to share our blueprint for success. Above all, we want the sector to improve, so here are five practical ways to ace a retrofit assessment.
Over time our approach has helped us become one of the most sought-after assessment teams in the UK. In this blog, you’ll learn:
- How our proven approach sets us apart
- Key data points for a thorough retrofit assessment
- Benefits of teamwork and collaboration
- Importance of accurate floor plans
- Tips for effective communication with stakeholders
What is a retrofit assessment?
First up, a small explainer. Retrofit assessments form a core part of the retrofit process outlined in PAS 2035, the overarching framework that details best practice guidance on energy retrofits in domestic buildings in the UK. The role of Retrofit Assessors is to be the eyes and ears of each project. They conduct the primary data collection for each dwelling in the retrofit assessment process, serving as the link between the project’s coordinator and designer. The coordinator relies on each report to inform the overall project direction, while the designer needs quality data to help them develop the most appropriate solution for each property – both of which stem from a successful retrofit assessment.

What does a good retrofit assessment look like?
A good retrofit assessment provides sufficient information to help the wider project team understand what needs to be done.
Great retrofit assessments goes beyond these minimum requirements, supplying comprehensive measurements, accurately scaled floor plans, photos, commentary, and insight into any problem areas encountered during the assessment.
A retrofit project benefitting from this level of detail has a much higher chance of success at the design and implementation stages because the coordinator has been given everything they need in order to make the right decisions.
5 steps to approach a retrofit assessment
Our team has developed a tried and tested five-step approach that they use to approach each site visit, ensuring the highest standard of retrofit assessments. Here’s how you can ensure success:
Step 1: Follow a set process
Every house is different and every resident has their own particular set of needs. This means that each visit can feel overwhelming at first. Following the same process every time makes the assessment smoother and more efficient, with much of the work seeming almost automatic.
After greeting the resident, we start off by drawing a basic floor plan by hand, noting all vents, lights, doors, windows, and heating systems. We then take a logical path through the property, moving methodically from room to room taking measurements and photos, observing issues, and making notes.
Key Takeaway: Following a consistent process during each site visit ensures thorough and efficient data collection for every assessment.
Step 2: Collect more data than the minimum requirement
While the industry standard submission tools only ask for limited information, our team collects far more than the minimal data. We’ve developed an extensive checklist of mandatory data points over time – in consultation with experienced Retrofit Coordinators.
There are lots of specific things to cover in a best practice assessment, from inspecting loft hatches to photographing corroded window sills. You need to tick each point in the checklist, in order, before you complete each inspection. The final retrofit assessment report should contain extensive photos, comments on issues encountered, and a professional floor plan drawn to scale. More data means better insights and a higher chance of project success.
Key Takeaway: Going beyond the minimum data requirements provides a comprehensive view of the property, ensuring higher-quality assessments.
Step 3: Work closely with the wider team
For large properties and Risk Pathway C projects that require an air test, our lead assessor will often work with another member of the team. This means there are two people double-checking the data and an additional point of view to contextualise any observations. This team-based approach ensures higher accuracy and quality control.
This is a step that is pretty unique to our cross-trained team of retrofit assessors: many are also qualified air tightness testing engineers, Part F ventilation testing engineers, and thermographers.
While most Pathway C retrofit projects require an external testing engineer to be drafted in, we keep the project in-house, reducing costs, improving quality, and increasing turnaround times.
Key Takeaway: Collaborating with a cross-trained team ensures double-checking of data and helps maintain high standards of accuracy and efficiency.
Step 4: Convert floorplans from freehand to SketchUp
An accurate floorplan is essential for any retrofit project. The most effective way to produce this is to convert the freehand drawings made on-site to professional standard SketchUp files.
We work as one big team on large projects with tight turnaround times. Onsite assessors will check data and draw floor plans freehand. Desk-based staff then convert these floor plans and QA all reports before they are submitted. Staff back at the office will support on-site assessors with the desk-based work mentioned above.
This ensures the most precise and scalable visualisation of the property, helping both the project designer and coordinator better understand the space and plan retrofitting solutions.
Key Takeaway: Converting freehand floorplans to professional SketchUp files ensures precise, scalable representations of each property.

Step 5: Work closely with your key stakeholders
Good communication is key. Conversations with people on-site can provide vital qualitative information to inform the project report, while energy efficiency information can be shared with residents if they want to make their own behaviour changes.
Developing a good relationship with the coordinator in charge of each project and discussing any issues or concerns as soon as they arise is critically important. Feedback from them can help us improve our reports and data collection, while our observations play an important role in guiding the subsequent project phases.
We iterate our approach each time we receive feedback and are continually improving our reports and processes.
Key Takeaway: Maintaining open communication with project stakeholders ensures any concerns are addressed early and contributes to improved report quality and project success.
Why retrofit assessments are crucial
A well-executed retrofit assessment forms the foundation of a successful retrofit project. It provides the necessary data for designing energy-efficient solutions, improving the building’s energy performance, and reducing carbon emissions. A thorough assessment helps ensure that the project will be completed on time, within budget, and with lasting benefits for both the property and its occupants.
What’s next?
We have provided this brief overview of some key parts of the retrofit process in the hope that coordinators and other assessors will find this list useful. We hope it helps you understand the importance of thorough and detailed assessments.
If you’re looking to learn more about retrofit assessments or need professional support for your next project, check out some of our other helpful articles:
Our experienced team is ready to help you guide your project to success. Reach out today to find out how our expert retrofit assessors can support your next retrofit project.
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