Murdishaw, Runcorn: PAS 2035 retrofit assessment and coordination across 132 homes

Greener Solutions Group provided Retrofit Assessment, Retrofit Coordination and specialist building-performance analysis on the Murdishaw regeneration and decarbonisation programme in Runcorn, Cheshire. The programme was delivered under Social Housing Decarbonisation Fund Wave 1 on behalf of Onward, and improved 132 homes with 528 retrofit measures installed. It represented more than £6 million of investment into the Murdishaw estate. Greener Solutions Group worked as part of the wider project team, combining standard PAS 2035 assessment work with thermal imaging surveys and fRsi condensation risk analysis to inform property-specific design decisions.

Project at a glance

• Location: Murdishaw estate, Runcorn, Cheshire

• Client body: Onward

• Funding programme: Social Housing Decarbonisation Fund (SHDF) Wave 1

• Homes improved: 132

• Retrofit measures installed: 528

• Total programme investment: more than £6 million

• Our scope: Retrofit Assessment, Retrofit Coordination, thermal imaging, fRsi analysis, technical design support

• Standard applied: PAS 2035

What was Greener Solutions Group's role on the Murdishaw programme?

Greener Solutions Group delivered Retrofit Assessment and Retrofit Coordination services, working alongside the delivery and design teams to confirm that proposed measures suited each individual property and could be installed in line with PAS 2035.

The scope covered:

• Retrofit Assessments across the housing stock

• Collection and review of property, condition and energy-performance data

• Retrofit Coordination throughout the relevant project stages

• Review of existing building fabric and property condition

• Identification of risks associated with proposed retrofit measures

• Thermal imaging surveys investigating heat loss, thermal anomalies and areas of concern within the building fabric

• Assessment of thermal bridging and junction performance

• fRsi calculations to assess internal surface-temperature factors at critical junctions

• Technical input to the development of appropriate retrofit solutions

• Support to the Retrofit Designer and wider design team

• Review of proposed measures against assessment and investigation findings

• Coordination of assessment, design and installation information to support PAS 2035 compliance

How did thermal imaging inform the retrofit strategy?

Thermal imaging surveys gave the project team a level of technical investigation that goes beyond a standard property assessment. The surveys produced additional evidence on how the existing building fabric was performing, identifying areas of increased heat loss, thermal bridging, insulation deficiencies and other anomalies that needed to be considered within the retrofit strategy.

Those findings were reviewed alongside property condition information and the proposed improvement measures, so that design decisions were based on observed performance rather than assumption.

Why were fRsi calculations used on this project?

fRsi is the temperature factor at the internal surface of a construction detail, used to assess the risk of surface condensation and mould growth. Where critical construction details and thermal bridges needed further investigation, Greener Solutions Group carried out fRsi calculations and analysis.

This mattered on Murdishaw because changes to the thermal performance of the building envelope can alter temperatures at existing junctions. Running the analysis during assessment and design meant potential condensation and mould risks were identified before installation rather than after it, and the findings fed directly into the retrofit design.

How did assessment work support the retrofit design?

Although the primary responsibility sat with assessment and coordination, the technical work fed straight into the design process. Assessment data, thermal imaging findings, fRsi analysis and property-specific observations were passed to the Retrofit Designer and wider delivery team so that identified risks could be addressed within the proposed design.

This created a clear chain from assessment, through technical investigation and risk identification, into retrofit design, coordination and installation. Integrating assessment and coordination with specialist building-performance analysis meant design decisions rested on a detailed understanding of the actual properties rather than generic assumptions.

How was PAS 2035 compliance maintained?

The Retrofit Coordination function maintained oversight of the retrofit process throughout the programme and made sure the required information was considered as the project progressed. This included reviewing the interaction between the existing building, the proposed measures, ventilation requirements and identified technical risks, while supporting communication between the assessment, design and delivery functions.

That approach upheld the whole-dwelling principles of PAS 2035, so individual energy-efficiency measures were treated as part of an integrated retrofit strategy rather than in isolation.

Project outcomes

• 132 properties improved

• 528 retrofit measures installed

• More than £6 million invested into the Murdishaw estate

• Improved energy performance across the housing stock

• Better understanding of existing building-fabric performance through thermal imaging

• Detailed assessment of thermal-bridge and condensation risks through fRsi calculations

• Property-specific technical information provided to support retrofit design

• Retrofit Assessment and Coordination delivered within the PAS 2035 framework

• Improved collaboration between assessment, design and installation teams

Technical retrofit expertise on large-scale decarbonisation programmes

Murdishaw shows what Greener Solutions Group offers beyond a standard Retrofit Assessment service. By combining Retrofit Assessment, Retrofit Coordination, thermal imaging, fRsi analysis and technical design support, the team gave the wider project the building-performance detail needed to make informed retrofit decisions.

That involvement bridged the gap between survey, assessment and design, flagging technical risks early and supporting robust, compliant and property-specific solutions. It is an approach that suits large-scale social housing decarbonisation programmes, where a consistent assessment process has to sit alongside the ability to investigate and resolve more complex building-fabric issues property by property.

Frequently asked questions

What is PAS 2035?

PAS 2035 is the publicly available specification that sets out the whole-dwelling approach to retrofitting existing domestic buildings for energy efficiency in the UK. It requires that measures are assessed, designed, installed and evaluated as an integrated package rather than individually, with defined roles including Retrofit Assessor, Retrofit Coordinator, Retrofit Designer and Retrofit Installer.

What does a Retrofit Coordinator do?

A Retrofit Coordinator oversees the end-to-end retrofit process for a dwelling, ensuring assessment findings, design decisions, ventilation requirements and identified risks are considered together and that the project meets PAS 2035 requirements. On Murdishaw, this included maintaining communication between the assessment, design and delivery functions.

What is the Social Housing Decarbonisation Fund?

The Social Housing Decarbonisation Fund is a UK government programme providing grant funding to social housing landlords to improve the energy performance of their least efficient homes. Murdishaw was delivered under Wave 1 of the fund.

Why is fRsi analysis important in retrofit?

fRsi analysis identifies whether internal surface temperatures at junctions and thermal bridges are likely to fall low enough to cause condensation and mould growth once retrofit measures change the performance of the building envelope. Carrying it out at design stage allows risks to be designed out rather than discovered after installation.

How many homes were improved at Murdishaw?

132 homes were improved and 528 retrofit measures were installed as part of the wider Murdishaw programme, which represented more than £6 million of investment into the estate.

Talk to us about your retrofit programme

Greener Solutions Group provides Retrofit Assessment, Retrofit Coordination, thermal imaging and fRsi analysis for social housing decarbonisation programmes across the UK. Get in touch to discuss your project.