Every retrofit project depends on one person getting the groundwork right first: the retrofit assessor. Before a coordinator can plan a scheme or a designer can specify a measure, someone has to establish exactly what a building is – its condition, its performance, and how its occupants actually use it. Get that foundation wrong, and every later stage inherits the error. Here’s what a retrofit assessor actually does, what it costs and how we deliver it.
In this blog, you’ll learn:
- A breakdown of the retrofit assessor’s role
- Why assessors are essential to every retrofit project
- What drives the cost of a retrofit assessment up or down
- How we deliver assessments nationwide, from small portfolios to large-scale programmes
- How we deliver assessments that exceed industry standards
Who are Retrofit Assessors?
A retrofit assessor is a trained professional tasked with assessing the energy performance, condition and occupancy of a building. Through detailed, full-condition property surveys, they gather the essential data needed to guide the decisions made by a retrofit coordinator or retrofit designer. Their work helps determine the best energy-saving measures for a property, taking into account the building and its inhabitants’ unique characteristics.
Whether dealing with older homes that must be retrofitted sympathetically to their architectural features or more modern properties with up-to-date systems, the assessor’s job is to collect comprehensive data on a property’s unique features, which can be passed on to the coordinator or designer. The extensive data collected on-site by the retrofit assessor can be used to inform decisions that will improve energy efficiency, cut down carbon emissions, and lower utility costs. Retrofit assessors ensure that all recommendations comply with PAS 2035, the UK’s standard for domestic retrofit, which guarantees that improvements are safe, effective, and sustainable.
We deliver PAS 2035 retrofit assessments nationwide – from social housing portfolios in Bristol and London to county-wide rural programmes – working across social housing, local authority and private property projects.
What Do Retrofit Assessors Do?
The job of a retrofit assessor involves much more than basic property surveys, focusing on ensuring that each property is fully prepared for energy-efficiency upgrades.
The retrofit assessment provides the crucial first steps for a retrofit project, establishing a foundation of information to enable retrofit designers and co-ordinators to best decide which measures are appropriate for a property. If this assessment is not carried out to a high standard, the ripples are felt throughout the whole project.
— Stanley Taylor, Lead Retrofit assessor at Building Energy experts
Here’s a breakdown of their core responsibilities:
- Conducting a Full Property Survey: Retrofit assessors visit homes to carry out a comprehensive evaluation of the building’s energy performance. They examine elements like insulation, ventilation, and heating systems to identify areas for improvement.
- Evaluating the Building’s Condition: Beyond energy efficiency, assessors look at the overall condition of the building, from its structural integrity to issues like damp, mould, or other defects that could affect retrofitting efforts.
- Evaluating the Building’s Occupancy: Integral to understanding what retrofit measures are appropriate for a property is the Occupancy assessment. Understanding how the occupants use the building, how many people occupy the space and any special considerations needed in regards to this information.
- Providing Critical Data for Retrofit Designers: The detailed insights they gather feed directly into the planning phase, where retrofit coordinators and designers use this data to decide which energy efficiency measures should be installed. This data is invaluable for retrofit coordinators and designers. It helps them determine which energy-saving measures are feasible and what limitations might affect the final design. Without this detailed insight, the overall retrofit plan would lack precision, risking inefficiencies or potential non-compliance with PAS 2035.
- Considering Heritage and Architectural Constraints: For properties in conservation areas or with historical significance, retrofit assessors must consider architectural limitations and identify what can and can’t be altered without compromising the building’s character.
- Reporting on Existing Installations: Assessors also identify any energy efficiency measures that may have already been installed, ensuring that new upgrades complement existing systems.
- Delivering Actionable Reports: After their assessment, the retrofit assessor prepares a detailed report outlining potential improvements, along with a condition survey, EPC (Energy Performance Certificate) and occupancy assessment. This document is essential for guiding the next steps in the retrofit process.
The Importance of PAS 2035 in Retrofit Assessment
The PAS 2035 standard is essential for ensuring that retrofits are carried out methodically and safely. Compliance with this standard helps ensure that energy-saving measures work as intended and meet the long-term performance goals of the property. Retrofit assessors play a critical role in aligning projects with PAS 2035, making sure that the recommendations are suitable and effective.
PAS 2035 retrofit assessments and energy efficiency testing across 28 retirement flats in Newbury – separating a ventilation problem from a structural one:
How Much Does a Retrofit Assessment Cost?
Cost is one of the questions we’re asked most, and the honest answer is that it depends on the scale and complexity of the project. A smaller archetype-based programme costs less than a full-scope assessment with cavity wall inspections, borescope surveys, blower door air tightness test and thermal imaging layered in, and a large portfolio benefits from economies of scale that a smaller programme won’t see.
Beyond survey scope, the main factors that move the price are:
- Portfolio size – archetype-based assessment reduces the cost per property on large-scale programmes rather than surveying every home individually
- Additional diagnostic testing – air tightness testing, thermal imaging, borescope cavity wall inspections and Matterport LiDAR scanning are priced as add-ons to the standard assessment
- Location and access – a dispersed rural programme carries different logistics to a concentrated urban one
- Heritage or Conservation Area status – properties needing ABBE Level 3-qualified heritage assessment carry a different scope to a standard post-war semi
We review our rate card regularly, and if you’ve found a lower quote for comparable, fully compliant PAS 2035 work, we’ll match or beat it where we can.
What Our Retrofit Assessors Do Differently
A retrofit assessment is only as good as the data behind it. Our approach has been recognised with Retrofit Assessor of the Year (2023 Retrofit Academy Awards) and Supply Chain Partner of the Year (2025 Unlock Net Zero Awards) wins. All of our assessors are accredited with Elmhurst and ECMK, and we’ve built our own bespoke data collection app to tailor each assessment to the specific property, rather than relying on generic, off-the-shelf reporting.
For more on our approach, see Jack Hannon’s presentation on speeding up and scaling retrofit assessments, delivered at Futurebuild 2024:
What’s Next?
The role of a retrofit assessor is crucial – from full property surveys to PAS 2035 compliance, they provide the foundation everything else in a retrofit is built on. Whether it’s a small-scale programme or a portfolio-wide scheme delivered to a tight timeline, that foundation is what we deliver.
We carry out PAS 2035 retrofit assessments nationwide, for portfolios and programmes of every scale.