Under the revised minimum energy efficiency standards (MEES) for privately rented buildings in England and Wales, due to be published at the end of 2021, it is expected that around 85% of non-domestic rented buildings will need to achieve an Energy Performance Certificate (EPC) rating of at least B by 2030. This will require significant energy retrofits on millions of properties. To ensure these retrofits are appropriate for the buildings being treated, to deliver the expected energy savings and ultimately provide good value for money, the British Standards Institute has published a new public specification – PAS 2038: 2021.
What is PAS 2038?
PAS 2038 sets out the process for the ‘whole-building’ retrofit of non-domestic properties. This includes assessing the condition of the existing building, developing a medium-term improvement plan for the energy performance of the building (for the period up to 2050), and the specification and evaluation of the energy efficiency measures (EEMs) needed to deliver this. It works in conjunction with PAS 2030:2019, which focuses on the installation and commissioning of the EEMs, forming a comprehensive Retrofit Standards Framework.
It essentially acts as the counterpart of PAS 2035: 2019 which sets out the ‘whole-house’ retrofit process for domestic properties.
Learn more about PAS 2035:2019
Ultimately, the Retrofit Standards Framework looks to raise competence and practice in the energy retrofit of buildings, ensuring EEMs deliver the expected performance improvements and avoiding unintended consequences from poorly considered or installed measures.
What energy efficiency measures (EEMs) are covered under PAS 2038?
PAS 2038 covers a wide range of EEMs, or packages of EEMs, including:
• improvements to insulation (including addressing thermal bridges);
• measures to increase the airtightness of the building fabric;
• low carbon heating technologies;
• more efficient heating, ventilation and lighting systems;
• smart controls;
• renewable technologies; and
• metering and monitoring systems.
Which buildings does PAS 2038 apply to?
PAS 2038 has been designed to span the full spectrum of non-domestic buildings, from hospitals and universities to shops and mixed-use buildings.
The standard identifies four main retrofit scenarios:
• retrofit of owner-occupied buildings;
• retrofit of unoccupied tenanted buildings;
• retrofit of tenanted buildings; and
• retrofit of parts of tenanted buildings occupied by a specific tenant.
How does PAS 2038 work?
PAS 2038 identifies the key role of a Retrofit Lead Professional who oversees improvements to a building. They are responsible for appointing all other members of the project team, retaining key documentation and ensuring all processes are completed in line with the recommendations of PAS 2038.
The specification also sets out a clear process that projects should go through:
1. Building assessment - The project is first considered by a suitably qualified assessor who creates a building assessment report considering a variety of factors including:
• the building construction, dimensions, architecture, significance and current condition;
• any constraints imposed by the site (orientation, elevation, location etc.) or as a result of local planning conditions;
• an occupancy survey covering occupancy volume and hours; and
• a review of building services including low carbon systems, bills and potential for future natural ventilation, passive cooling or improved daylighting and fabric.
Notes will be made on any defects to identify whether or not they need to be addressed prior to any retrofit work.
2. Improvement option evaluation – Based on the building assessment report, an evaluation is then carried out to identify a suitable package of EEMs based around the energy efficiency targets and any restraints identified in the assessment. This may include a heritage impact assessment in the case of protected buildings. In addition to the building assessment, the evaluation is also informed through energy performance simulation modelling carried out in line with CIBSE TM 54.
The evaluator then looks at the energy cost effectiveness and pay-back period of the different measures and provides a final improvement option evaluation report with a recommended package of improvements. Both reports are provided to the client and the intended outcomes of the project agreed.
3. Medium term improvement plan – based on these reports and the agreed outcomes, a medium-term improvement plan is then drawn up for the next 20-30 years. This identifies a retrofit strategy for the building, creating a clear schedule for the delivery of EEMs. The plan is retained in an electronic format to allow it to be updated as work is completed and adjusted as new technologies become available.
4. Design and specification – a designer will review all of the documents created to date and produce a retrofit design which includes:
• a summary of the building, any constraints and the overall design intent;
• specification of the different materials along with installation guidance;
• specific construction details covering all key junctions;
• detailed information about the building services;
• the sequence for installing EEMs;
• testing, commissioning and maintenance instructions; and
• a list of any product guarantees.
5. Installation & commissioning - The design is then passed to the installer to quote for the work and, provided this meets the available budget, work can commence on all or part of the identified work in accordance with the agreed schedule. The installation and commissioning of the EEMs is completed in accordance with PAS 2030: 2019 by a suitably qualified installer.
6. Handover – At handover, the client should be provided with clear information about how to correctly operate and care for new measures along with a log book which is completed in accordance with CIBSE TM31 and includes all of the building reports and records of testing and commissioning. The Retrofit Lead Professional also retains electric copies of all these documents along with guarantees and product manuals.
7. Fine tuning – at least 3 months after handover, a fine tuning assessment is carried out to confirm that systems are performing correctly and to make adjustments to address any anomalies. Any changes are added to the log book.
8. Evaluation – at least 1 month later, an evaluator will also carry out a basic evaluation asking occupants to fill out a questionnaire to confirm their satisfaction with the measures and identify any issues. Based on these, the evaluator then makes recommendations which are circulated to the team. If significant issues are identified, a further evaluation will be carried out (with the client’s permission) to identify the reasons for any underperformance and confirm remedial work. This may include a range of testing measures including airtightness, moisture and energy-monitoring as well as a review of all the reports. The findings will then be circulated around the team along with remedial recommendations.
How can I get accredited to PAS 2038?
PAS 2038 is a process, rather than an accreditation itself. This means it is not necessary to pass a training course, but project teams must be able to clearly demonstrate that they have conformed with all of the steps and requirements outlined in the specification. Appropriate training and accreditation can be used to show that you have the relevant competency and processes in place which meet the standard. PAS 2038 does identify a number of qualification requirements for different parties involved in the project.
Is PAS 2038 mandatory?
PAS 2038 is not mandatory for retrofit work although it is likely to be a requirement for any future government funded retrofit schemes impacting the non-domestic sector. We would strongly encourage that energy retrofit work on non-domestic projects is completed in accordance with the process to ensure the best long-term results.