Wakefield District Housing: whole-house fabric-first retrofit with Concept Heating

Greener Solutions Group worked in partnership with main contractor Concept Heating to deliver a large-scale whole-house retrofit programme for Wakefield District Housing. Greener Solutions Group provided the complete PAS 2035 service, covering assessment, energy modelling, design and coordination, alongside direct delivery of PAS 2030-compliant cavity wall and loft insulation. Concept Heating delivered Q-Bot robotic underfloor insulation and AIREX smart air bricks. Together the measures addressed heat loss through walls, roofs and floors as a single coordinated fabric-first package.

Project at a glance

• Client: Wakefield District Housing

• Main contractor: Concept Heating

• PAS 2035 and insulation delivery partner: Greener Solutions Group

• Approach: whole-house, fabric-first retrofit

• Greener Solutions Group services: PAS 2035 Retrofit Assessment, Coordination and Design, cavity wall insulation, loft insulation, retrofit compliance and quality assurance

• Measures delivered by Concept Heating: Q-Bot underfloor insulation, AIREX smart air bricks

• Standards applied: PAS 2035 and PAS 2030

What was Greener Solutions Group's role?

Greener Solutions Group provided an integrated retrofit service covering both the professional PAS 2035 requirements and the physical installation of insulation measures.

The scope included:

• PAS 2035 Retrofit Assessments

• RdSAP energy assessments and improvement modelling

• Retrofit Coordination

• Improvement Options Evaluations (IOEs)

• Medium-Term Improvement Plans (MTIPs)

• Retrofit Design and technical support

• Ventilation assessments and consideration of whole-dwelling ventilation requirements

• PAS 2030 cavity wall insulation

• PAS 2030 loft insulation

• Pre-installation technical reviews

• Coordination between different retrofit measures and installation teams

• Quality assurance and compliance documentation

• Post-installation review and project close-out support

  
  

This integrated approach kept the PAS 2035 process closely connected to what was actually being delivered on site.

What is a fabric-first retrofit approach?

A fabric-first approach improves the thermal envelope of a building, its walls, roof, floors and airtightness, before turning to heating systems or renewable technologies. Reducing the amount of heat a home loses in the first place means any subsequent system can be smaller, cheaper to run and better matched to the property.

On this programme, Greener Solutions Group assessed each dwelling individually to establish its existing condition, construction type, insulation levels, ventilation provision and energy performance. That information determined an appropriate package of measures for each property.

Where suitable, Greener Solutions Group then installed cavity wall and loft insulation in accordance with PAS 2030, reducing heat loss through two of the principal elements of the building envelope. Concept Heating delivered Q-Bot underfloor insulation, addressing heat loss through suspended floors with minimal disruption to residents, and installed AIREX smart air bricks where appropriate to provide intelligent control of subfloor ventilation.

Why does combining multiple insulation measures need careful coordination?

Improving the airtightness and thermal performance of several elements of a property at once can alter its moisture and ventilation characteristics. Measures that are individually sound can create problems in combination if their interactions are not considered.

Greener Solutions Group's Retrofit Coordinators provided oversight throughout, confirming that proposed measures suited each dwelling and that potential unintended consequences were identified and managed. Particular consideration was given to:

• Existing property condition and defects

• Moisture and condensation risk

• Ventilation requirements

• Existing insulation and construction details

• Compatibility between individual retrofit measures

• Thermal bridging and continuity of insulation

• Sequencing of works

• Resident impact

• PAS 2030 installation requirements

• Evidence and documentation required for project compliance

  
  

This mattered most where cavity, loft and underfloor insulation were combined on the same property.

How did the collaboration with Concept Heating work?

As main contractor, Concept Heating retained responsibility for overall project delivery and delivered the specialist Q-Bot and AIREX measures. Greener Solutions Group provided the PAS 2035 technical framework around the programme while also taking direct responsibility for cavity wall and loft insulation installations.

That created a streamlined delivery model running from assessment, through energy modelling, improvement strategy, retrofit design and coordination, into PAS 2030 installation, quality assurance and completion. Because Greener Solutions Group was involved at both the technical and installation stages, there was greater continuity between the original retrofit strategy and the measures ultimately installed.

How was quality and compliance managed?

Our technical and operational teams worked together to confirm that insulation measures were suitable for each property before installation and that completed works aligned with the requirements established through the PAS 2035 process.

This helped Concept Heating manage the technical complexity of delivering multiple fabric measures across an occupied housing portfolio, while maintaining a clear audit trail from assessment through to completion.

Project outcomes

• Improved thermal performance of residents' homes

• Reduced heat loss through walls, roofs and floors

• A coordinated fabric-first retrofit strategy

• PAS 2035-compliant assessment, design and coordination

• PAS 2030-compliant insulation installation

• Improved understanding of individual property condition and performance

• Better integration between retrofit design and site delivery

• Consideration of ventilation, moisture and building performance throughout the process

• A robust technical and compliance trail for the client and main contractor

  
  

Retrofit delivered as one integrated service

The Wakefield District Housing programme shows Greener Solutions Group operating as both a PAS 2035 technical consultancy and a PAS 2030 installation contractor. Combining assessment, coordination, design and compliance services with direct delivery of cavity wall and loft insulation meant Concept Heating had a joined-up retrofit solution rather than individual measures treated in isolation.

Working alongside Concept Heating's Q-Bot and AIREX installations allowed the project team to deliver a coordinated whole-house approach focused on improving building performance, maintaining compliance and achieving better outcomes for residents.

Frequently asked questions

What is Q-Bot underfloor insulation?

Q-Bot is a robotic system that applies insulation to the underside of suspended timber floors from within the void beneath the property. Because the robot works from the crawl space, floorboards do not need to be lifted, which significantly reduces disruption to residents in occupied homes.

What are AIREX smart air bricks?

AIREX smart air bricks replace conventional air bricks and control subfloor ventilation automatically, responding to temperature and humidity conditions. They allow ventilation to continue where it is needed to manage moisture, while limiting unnecessary heat loss through the subfloor void.

What is the difference between PAS 2035 and PAS 2030?

PAS 2035 is the specification governing the whole-dwelling retrofit process, including assessment, design, coordination and evaluation. PAS 2030 governs the installation of the energy-efficiency measures themselves. Funded retrofit programmes require compliance with both.

What does a Retrofit Coordinator do on a multi-measure project?

A Retrofit Coordinator oversees the whole retrofit process for a dwelling, ensuring that assessment findings, design decisions, ventilation requirements and identified risks are considered together. On multi-measure projects this includes managing how measures interact, sequencing works and identifying unintended consequences before installation.

Why does ventilation matter when insulating a home?

Insulation and airtightness improvements reduce the amount of uncontrolled air movement through a building. Without adequate ventilation, that can raise internal humidity and increase the risk of condensation, damp and mould. PAS 2035 requires ventilation to be assessed as part of any retrofit rather than treated as a separate consideration.

Talk to us about your retrofit programme

Greener Solutions Group provides PAS 2035 retrofit assessment, coordination and design alongside PAS 2030 insulation installation for social housing retrofit programmes across the UK. Get in touch to discuss your project.