Retrofitting the UK’s housing stock is essential to achieve net zero targets

Jerome Edwards, director of building surveying in the UK, shares his insights into retrofitting, including the PAS 2035 standard. He highlights why the construction industry must embrace the retrofit revolution and accept a higher degree of professional obligation.

The government is committed to achieving net zero carbon by 2050. Our built environment accounts for 25% of the UK’s total carbon emissions, with domestic heating representing around 18% of energy consumption.

With around 80% of existing buildings expected to still be standing by 2050, we must look towards the retrofitting of the UK’s housing stock to increase levels of energy performance.

The UK has some of the oldest, worst performing and energy inefficient homes in Europe. The retrofit challenge presents an opportunity to transform our homes into high performing assets that are healthy and affordable.

What is domestic retrofit?

Domestic retrofit improves or modifies existing residential properties to make them more energy-efficient and sustainable. It involves introducing new energy-saving technologies or passive measures to reduce energy demand and associated carbon emissions that will enhance the building’s overall performance. By making homes greener, they will be more environmentally friendly, as well as cheaper to run and more comfortable to live in.

What is PAS 2035?

In 2015, the UK government commissioned the Each Home Counts review to identify and tackle the high level of failure in domestic retrofit. The goal was to determine a better process for the delivery of energy efficiency projects across the UK, raising consumer experience as well as addressing the unintended performance gap that is often associated with retrofit.

PAS 2035 was created because of this review, with the backing of industry and the government’s Department for Energy Security and Net Zero.

PAS 2035 is the overarching process within the BSI Retrofit Standards Framework that establishes a best practice approach towards managing the technical and process risks associated with retrofit.

The ‘whole house’ approach considers the entire building as a system, providing a comprehensive overview of the property to determine the most suitable energy efficiency measures to install.

What roles are required for PAS 2035?

There are five roles required to create a retrofit team:

  • Retrofit assessor: provides an in-depth assessment of the current arrangement and build of the property. This includes ways to improve after analysing collected data.
  • Retrofit co-ordinator: this is an end-to-end role with full responsibility for demonstrating compliance with PAS 2035 and protecting the client and public interests.
  • Retrofit designer: reviews the dwelling assessment and develops a retrofit strategy to provide a fully compliant retrofit design, ensuring the requirements of the risk and client’s objectives are both met.
  • Retrofit installer: a PAS 2030 certified and TrustMark registered contractor who installs the retrofit measures, specified in accordance with PAS 2035.
  • Retrofit evaluator: conducts technical monitoring and post-occupancy evaluation once the works are complete.

What steps are in the PAS 2035 process?

The PAS 2035 standard is underpinned by six core stages from project inception to completion and handover.

Step 1: Intended outcomes

Role: Retrofit co-ordinator

The client’s goals, objectives and overarching retrofit brief need to be discussed and clearly understood.

Step 2: Risk assessment

Role: Retrofit co-ordinator

The project risks depend on the expected works that will take place. Different levels of risk will be managed differently and have varying requirements under PAS 2035.

Step 3. Whole dwelling assessment

Role: Retrofit assessor

This is a thorough assessment of each property that will provide accurate information, so the right decisions are made.

Step 4. Design and co-ordination

Role: Retrofit co-ordinator and retrofit designer

Most retrofit strategies will be implemented over a long-term period. As a result, the client will be provided with a medium-term plan towards achieving optimal energy performance.

Step 5: Installation

Role: Retrofit installer and retrofit co-ordinator

The installation will take place by a contractor in accordance with PAS 2030, which is the framework and procedure for installation of energy efficiency measures.

Step 6: Monitoring and evaluating

Role: Retrofit evaluator

The project should benefit from an appropriate level of evaluation to measure its success, effectiveness and provide key learning opportunities for future retrofit delivery.

Is PAS 2035 mandatory?

No, but since 20 June 2021, all UK retrofit projects in receipt of public funding must specify PAS 2035 and evidence compliance is achieved throughout delivery.

We recommend that PAS 2035 is adopted for all residential retrofit projects, publicly funded or not, as it provides a clear and structured path to compliance and best practice.

Many social housing providers are now embedding the PAS 2035 process into their asset management, investment, and decarbonisation programmes as a minimum technical standard.

Find out more about PAS 2035.

How can we help?

Retrofit projects are large, complex and usually delivered at speed – stretching internal capabilities to plan and execute them effectively.

Clients must think about retrofit at the start of their project and from a whole-life perspective to ensure long-term sustainability and value creation. Monitoring and analysing data throughout an assets’ lifetime are essential to enable holistic decision-making on decarbonisation options.

Our multidisciplinary team is well-placed to support the delivery of your retrofit programme. Our building surveying and sustainability teams have developed industry knowledge and technical capability, ensuring good quality outcomes are achieved through retrofit delivery.

We hold the appropriate qualifications and accreditations to fulfil all PAS 2035 roles, providing a professional and fully integrated service.

Our team has been at the forefront of the implementation of the retrofit standards framework, particularly PAS 2035. We have supported several large-scale programmes across the UK, lifting thousands of homes up to modern energy performance standards.

Benefits of our retrofit service:

  • Compliance: our team are seasoned retrofit practitioners who understand the technical requirements to evidence full compliance and achieve good quality outcomes.
  • Quality: we are professional, fully qualified specialists.
  • Fully insured: all retrofit services are covered by our public liability and professional indemnity insurances.
  • Efficiency: we have developed robust systems and ways of working - utilising digital workflows to promote data sharing to minimise the risk of projects stalling or failing.

As retrofit co-ordinator, we will manage all aspects of your PAS 2035 project, including taking responsibility for the following deliverables:

  • Project managing and protecting you and the public from poor quality retrofit.
  • Ensuring projects are safe, of a high-quality and perform to their maximum potential.
  • Providing your teams, consultants and contractors with informed advice and support.
  • Providing you with assurances that project risks are being effectively managed and quality is being maintained.
  • Completion of an initial and ongoing risk assessment for each project.
  • Completion of an options appraisal to assess the most effective package of energy efficiency measures.
  • Developing a retrofit and decarbonisation strategy which aligns with net zero carbon aspirations.
  • Monitoring works during the construction phase and facilitating toolbox talks and site meetings, where necessary.
  • Undertaking building performance evaluations to measure success and provide evidence that intended outcomes have been achieved - mitigating the performance gap.

Achieving our decarbonisation targets will require a major step-change in how we manage existing stock. Embracing the retrofit revolution and accepting a higher degree of professional obligation will help add value to make building a better future possible.

Supporting our clients decarbonise their existing estates through retrofitting

We are delighted to announce our upcoming initiative in collaboration with Stroud District Council – a comprehensive programme focused on PAS2035-compliant retrofits. In the initial phase, we are assessing 200 properties which includes delivering the following services:

  • Comprehensive assessments: we are providing in-depth retrofit assessments covering condition, energy efficiency, ventilation, and occupancy. Our rigorous evaluations ensure compliance and accuracy in every aspect.
  • Collaborative approach: we work closely with Stroud District Council, designers and installers, fostering seamless communication and adherence to the highest industry standards.
  • Post-installation support: we deliver post-installation services, including energy performance certificates (EPCs), tenant education and operational assistance, guaranteeing sustained efficiency.
  • Data collection and reporting: we meticulously collect valuable data essential for reporting, evaluation, and case studies. Our approach aligns with Social Housing Decarbonisation Fund Wave 2 requirements, ensuring that we remain at the forefront of industry standards.
  • Quality assurance: regular site visits are conducted to uphold the highest standards. Feedback and evaluations serve as vital tools, confirming the success of each project.

We are dedicated to ensuring energy-efficient, compliant, and comfortable homes are provided for the community. This initiative represents our commitment to creating a sustainable and eco-friendly living environment for all.

Get in touch

For more information on our PAS 2035 services, download our flyer. Or to speak to someone about how we can support on retrofitting, especially putting PAS 2035 into practice, please contact:

Jerome Edwards

Director – Building Surveying

[email protected]

+44 7767 625 509

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