What Is a Retrofit Assessment? Everything You Need to Know
What Is a Retrofit Assessment? Everything You Need to Know
What Is a Retrofit Assessment? Everything You Need to Know

Improving the energy efficiency of homes is more important than ever, and a retrofit assessment plays an important role in achieving this goal. By evaluating a property’s current energy performance and identifying opportunities for enhancement, retrofit assessments ensure homes meet modern standards while addressing environmental concerns.
In this guide, we’ll explore the essentials of retrofit assessments, from what they involve to how they contribute to energy performance, sustainability, and the broader push toward net-zero emissions.
Key Takeaways
- Definition and Purpose: A retrofit assessment is a detailed evaluation of a property’s energy performance, condition, and occupancy. Conducted by a qualified assessor, it identifies areas like insulation, heating systems, and ventilation that need improvement, providing a foundation for energy-saving measures.
- Benefits and Outcomes: Retrofit assessments help reduce energy bills, lower carbon emissions, and improve thermal comfort. They also align homes with regulations such as PAS 2035 and can increase property value, making them a vital step toward sustainable living.
- Holistic and Custom Approach: By focusing on the property’s unique characteristics, including structural condition and usage patterns, retrofit assessments ensure tailored solutions. This "whole-house" approach addresses energy efficiency and compliance while supporting broader net-zero goals.
What is a Retrofit Assessment?
A retrofit assessment is a comprehensive evaluation of a property's current condition and energy performance, carried out by a qualified Retrofit Assessor. It goes beyond a standard energy assessment to examine key areas such as insulation, ventilation, and heating systems, while also considering the building's overall condition and how it's used.
The assessment typically includes:
- An energy performance evaluation to identify opportunities for improving efficiency.
- A condition report assessing the structural and physical state of the property, including issues like damp or mold.
- An occupancy assessment to understand how the building is used and any special considerations for the occupants.
- Consideration of heritage and architectural constraints for older or historically significant buildings.
This comprehensive assessment serves as a crucial foundation for enhancing energy efficiency and ensuring compliance with standards like the Publicly Available Specifications (PAS) 2035, which governs the retrofitting of domestic properties. It provides detailed insights that guide Retrofit Coordinators and Designers in planning appropriate energy-saving measures.
The resulting report, which includes an energy report, condition survey, and occupancy assessment, acts as a roadmap for improving the property's energy efficiency while considering its unique characteristics and the needs of its occupants. This approach supports broader sustainability goals and helps ensure that retrofit measures are appropriate, effective, and tailored to the specific property.
What is PAS 2035?
PAS 2035 is the UK's official standard for domestic retrofitting, providing a comprehensive framework to ensure consistent, high-quality energy efficiency improvements.
Developed in response to the 2015 Each Home Counts review, it outlines detailed requirements for assessment, design, installation, and monitoring of retrofit projects. PAS 2035 emphasizes a "whole-house" approach, considering not only the property's needs but also occupant comfort, health, and well-being, as well as architectural and cultural heritage. It works in conjunction with PAS 2030, which focuses on installation aspects.
The standard establishes processes for assessing and implementing improvement measures best suited to each individual home, including risk assessments and compatibility checks. PAS 2035 is mandatory for all publicly funded projects and businesses operating under TrustMark.
By adhering to this standard, professionals can achieve long-term energy savings, improved property performance, and compliance with industry standards, while also ensuring satisfactory outcomes for occupants through post-retrofit performance monitoring. This comprehensive approach fosters trust, sustainability, and addresses previous issues of retrofit measures being considered in isolation.
What Does a Retrofit Assessor Do?
A retrofit assessor evaluates a property’s energy efficiency and identifies opportunities for improvement. Here's what their role involves:
- Conduct Comprehensive Surveys
Retrofit assessors perform detailed inspections of properties, focusing on areas like insulation, ventilation, and heating systems. These surveys form the foundation of a tailored plan for energy upgrades. - Collect Key Data
They gather extensive information on the property's condition, energy performance, and usage patterns. This includes assessing potential damp issues, wall insulation, windows, and conducting an occupancy assessment to understand how the building is used. - Identify Ventilation Needs
Proper ventilation is essential for maintaining indoor air quality and avoiding condensation. Assessors analyse existing systems and recommend improvements where necessary, as part of the overall energy efficiency strategy. - Evaluate Heritage and Architectural Constraints
For older or historically significant buildings, assessors consider heritage and architectural constraints that may impact retrofit options. - Collaborate with Retrofit Coordinators
Working under the PAS 2035 framework, retrofit assessors share their findings with coordinators to ensure the proposed energy measures align with regulatory standards and sustainability goals. - Prepare Comprehensive Reports
They compile detailed reports including an energy assessment, condition survey, and occupancy assessment, providing crucial data for retrofit coordinators and designers. - Support Broader Energy Goals
By identifying precise improvements and considering the property holistically, they contribute to the creation of an energy-efficient retrofit plan that aligns with broader sustainability objectives. - Stay Updated on Regulations and Technologies
Retrofit assessors must keep abreast of the latest regulations, standards, and energy-saving technologies to provide the most current and effective recommendations.
A retrofit assessor's role is pivotal in transforming properties into energy-efficient, compliant, and sustainable homes, working alongside various stakeholders in the retrofit process.

What is the Difference Between a Retrofit Assessor and a Retrofit Coordinator?
A retrofit assessor and a retrofit coordinator play distinct but complementary roles in the energy efficiency upgrade process. A retrofit assessor conducts comprehensive property evaluations, gathering detailed data on insulation, ventilation, energy performance, and occupancy patterns to identify areas for improvement. They provide crucial initial information for the retrofit project.
In contrast, a retrofit coordinator oversees the entire retrofit process, from planning to completion. They ensure compliance with PAS 2035 standards, manage stakeholders, conduct risk assessments, produce improvement plans, and oversee the design, implementation, and monitoring of energy efficiency measures. The coordinator considers not only the occupant's needs and budget but also manages technical and process risks associated with the project.
While assessors provide the foundational data, coordinators are mandatory for all retrofit projects to comply with PAS 2035, utilising the assessor's insights to guide a comprehensive and effective retrofit strategy. Together, these roles ensure a thorough, compliant, and successful energy efficiency upgrade process.
What Are the Benefits of a Retrofit Assessment?
The benefits of a retrofit assessment are:
Lower Energy Bills
By identifying areas of energy loss, a retrofit assessment helps implement upgrades that reduce energy consumption and lower utility costs.
Improved Thermal Comfort
Enhanced insulation, efficient heating systems, and proper ventilation create a more comfortable indoor environment year-round, potentially reducing health risks associated with damp or cold conditions.
Reduced Carbon Emissions
Retrofitting your home based on assessment recommendations contributes to a lower carbon footprint, aligning with sustainability goals. The study "Reduction in Energy Consumption and CO₂ Emissions by Retrofitting an Existing Building to a Net Zero Energy Building for the Implementation of SDGs 7 and 13" quantifies energy savings and carbon emissions reductions achieved through retrofitting. Retrofitting measures reduced energy consumption by 34% and CO₂ emissions by 32%. The integration of a 41.6 kW solar system further eliminated 25.2 metric tons of CO₂ annually, converting the building into a net-zero energy building (NZEB). The combined retrofitting and renewable energy strategies contribute to achieving Sustainable Development Goals (SDGs) 7 and 13, highlighting their significance in energy efficiency and climate action initiatives (1).
Increased Property Value
Energy-efficient homes are more appealing to buyers, making retrofitting an investment that enhances your property's market value. The study "Increasing the Market Value of Buildings Through Energy Retrofitting: A Comparison of Actual Retrofit Costs and Perceived Values" examines how energy retrofits impact property valuation and buyer preferences within the European real estate market. Using case studies in Italy and France, it highlights that deep retrofitting measures can increase buyer willingness-to-pay (WTP) by 13.5% over pre-retrofit conditions. The study identifies factors like energy-efficient windows, HVAC systems, and renewable energy as key drivers of higher property valuations. It underscores the dual benefits of retrofits—energy savings and increased market value—while emphasizing regional market dynamics in shaping retrofitting outcomes (2).
Regulatory Compliance
Retrofit assessments ensure your property meets energy standards and regulations, such as the minimum EPC rating of E for rental properties, avoiding potential penalties.
Personalised Energy Solutions
Each assessment provides tailored recommendations for your home, addressing specific challenges and offering targeted solutions for improvement.
Access to Funding
Retrofit assessments can help homeowners access funding opportunities, such as the ECO4 scheme, for energy efficiency improvements.
Future-Proofing
With energy prices expected to remain high, investing in retrofit measures now could lead to significant long-term savings.
Compliance with PAS 2035
Retrofit assessments are a key part of compliance with PAS 2035, the government-mandated standard for domestic retrofit projects.
Taking a retrofit assessment is a vital step toward achieving a sustainable and energy-efficient home while enjoying these long-term benefits and potentially accessing available funding schemes.
How Do Energy Performance Certificates (EPCs) Influence Retrofit Decisions?
Energy Performance Certificates (EPCs) play a significant role in influencing retrofit decisions by providing an overview of a property's current energy efficiency. They highlight areas needing improvement, such as insulation, heating systems, or ventilation.
However, while EPCs offer valuable insights, a retrofit assessment following the PAS 2035 standard provides a more comprehensive evaluation, including a detailed in-depth survey of the property's condition, occupancy patterns, and improvement potential.
This process can help properties progress toward higher EPC ratings, potentially increasing property value. It's important to note that EPCs have limitations, including standardised assumptions about occupancy and a 10-year validity period, which may not reflect recent property changes.
While EPCs and retrofit assessments can guide decisions to reduce energy costs and align with sustainability goals, they should be viewed as complementary tools in the broader context of energy-efficiency improvements.
Conclusion: How Does a Home Retrofit Assessment Improve Energy Performance?
A home retrofit assessment is a pivotal step in enhancing energy performance by providing a comprehensive evaluation of a property's condition and energy efficiency potential. Aligned with PAS 2035 standards, it identifies areas for improvement such as insulation, heating systems, and ventilation, while also considering the building's structure, occupancy patterns, and the occupants' needs.
This holistic approach, which prioritises a "Fabric First" strategy before considering options like renewable energy systems, empowers homeowners to make informed decisions about energy efficiency upgrades.
The assessment not only guides improvements to reduce energy costs and carbon emissions but also addresses broader issues like damp or mold, ensuring overall building health.
By providing access to funding opportunities such as the ECO4 scheme and potentially increasing property value, a retrofit assessment represents a valuable investment in both environmental sustainability and long-term property efficiency.
This comprehensive process helps create more comfortable, energy efficient living spaces while avoiding unintended consequences that could arise from considering retrofit measures in isolation.
Retrofit Assessment FAQ's
A typical retrofit assessment takes 1-3 hours, depending on the size and complexity of the property.
The cost varies but generally ranges from £120 to £950, depending on factors such as the assessor, location, and property size.
While some local authorities may offer incentives for retrofit assessments, there is no universal grant scheme specifically for the assessments themselves. However, retrofit assessments can help homeowners access funding for energy efficiency improvements through schemes like ECO4.
Reference List
(1) Razzaq I, Amjad M, Qamar A, Asim M, Ishfaq K, Razzaq A and Mawra K (2023) Reduction in energy consumption and CO2 emissions by retrofitting an existing building to a net zero energy building for the implementation of SDGs 7 and 13. Front. Environ. Sci. 10:1028793. doi: 10.3389/fenvs.2022.1028793
Research licensed under CC BY 4.0 DEED.
No changes were made to the material.
(2) Gholamzadehmir, M.; Pandolfi, A.M.; Del Pero, C.; Leonforte, F.; Sdino, L. Increasing the Market Value of Buildings Through Energy Retrofitting: A Comparison of Actual Retrofit Costs and Perceived Values. Buildings 2025, 15, 376. https://doi.org/10.3390/buildings15030376
Research licensed under CC BY 4.0 DEED.
No changes were made to the material.
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