IHBC’s Technical Update: Panel chair Prof. John Edwards examines PAS 2038 ‘… a new BSI retrofit standard and what it means for older buildings’

Professor John Edwards, Director of Edwards Hart Consultants and a member of the panel that produced the new  ‘Publicly Available Specification’, PAS 2038, offers new insights on this ‘new BSI retrofit standard and what it means for older buildings’.

… PAS’s ….are produced through consensus. There was greater representation of heritage experts on the panel producing PAS 2038 compared to PAS 2035…

John Edwards writes:

Domestic buildings have received a lot of attention in the past few years, but now it’s time to focus on non-domestic buildings with the publication of PAS 2038 earlier this month.  This is the UK standard for the energy efficiency and retrofit of non-domestic buildings and that includes historic buildings, traditional buildings, and those buildings with special protection.  It is largely a process that incorporates, at least to some degree, BS 7913: 2013: Guide to the Conservation of Historic Buildings and BS EN 16883: 2017: Conservation of Cultural Heritage – Guidelines for improving the energy performance of historic buildings.  It requires training and a qualification in the energy efficiency retrofit of older buildings and conservation accreditation / certification for designers. Therefore, it is time for those who care about our older and protected buildings to get behind PAS 2038, because on the whole it’s a force for good, not least because we need to sensibly improve the energy performance of all buildings.

Whilst PAS 2038 is largely a process that sets out the overall approach to be taken, it also expresses detailed requirements on what needs to be done.  It includes specific roles with specific responsibilities and describes the competences required from individuals performing those roles. There isn’t an equivalent authoritative document that covers this most important subject which relates to around 2 million UK buildings. There currently isn’t a mandatory requirement to comply with it, but as its production was funded by UK Government, then this could change in the future. Note that the equivalent document for dwellings is PAS 2035, and for this there is a mandatory requirement for many government and ECO (Energy Company Obligation fund) funded schemes to comply with it.

The types of buildings coming under PAS 2038 is vast.  This includes offices, shops, factories, and warehouses, but it also includes schools, universities, hotels, restaurants, museums, churches, cinemas, theatres, hospitals, castles, and many other types of buildings which are not used as dwellings. Obviously, with such a wide range of buildings there are many different construction types that will come under PAS 2038, and buildings of vastly different scales.  PAS 2038 deals with this challenge by making provision for these differences. For example, PAS 2038 directs non-domestic buildings which are domestic in size and type of construction along with the type of building services you would get in the dwelling, to follow PAS 2035 and consequently PAS 2038 does not apply to these buildings. Traditional construction is also differentiated from other construction types and there is some difference in the approach to exceptionally large buildings.

PAS 2038 is intended to accommodate projects of different types and sizes.  It is about retrofit and not replacing like for like and therefore unfortunately not the maintenance and repair work that would improve energy efficiency, but it does state in the side notes that putting the building into good repair must be actioned before retrofit.  However, if an element is being replaced with an equivalent that has an improved thermal performance, then that would come under this document. It acknowledges that energy efficiency retrofit work could come under existing types of programmes of improvements, but also as separate retrofit projects.  If a project is to comply with  PAS 2038, however it must follow the processes including making sure that all the activities described in the documents are followed and be in accordance with it. This includes having in place individuals undertaking specific roles.

There are three specific lead roles within PAS 2038. The Retrofit Lead Professional is a professional member of the retrofit project team appointed to lead and coordinate the work.  In essence, this person is the project manager and dependent on the main focus of the work, this could be a professional whose expertise lies in building fabric or building services.  The Lead Assessor is a member of the project team who leads the assessment of the existing building. The assessment includes the use of the building, its condition, and its energy performance although the assessment can rely upon documents and information that already exists.  The Lead Designer is a member of a retrofit project team who leads the design and specification of retrofit measures or package of measures.

There are qualification and professional membership requirements. There are also some specifically mentioned  issues such as U value calculations, condensation risk assessments, thermal bridging calculations and energy performance where qualifications in such subjects are also required.

Where traditionally constructed buildings (defined as ‘ building construction incorporating vapour permeable materials that both absorb moisture and readily allow its evaporation’) and protected buildings (e.g., a listed building, a building in a conservation area) are concerned there are additional qualification requirements. Members of the project team undertaking or leading assessments, improvement option evaluations, establishing intended outcomes, preparation of an improvement plan or submitting or facilitating applications for statutory approvals shall also hold an additional qualification which PAS 2038 describes as a Level 3 Award qualification covering the retrofitting of traditional buildings.  We can assume this to be at least a requirement for the Retrofit Lead Professional and the Lead Assessor.   It can be obtained through successfully undertaking a two-day course which is available from the Environment Study Centre (www.environmentstudycentre.org).  Additionally, members of the project team undertaking or leading the design and specification of retrofit work shall also be accredited or certified in building conservation.

The process of retrofitting a traditionally constructed building or a protected building also involves some additional requirements. This means that the assessment of the building should be carried out in accordance with BS EN 16883: 2017: Conservation of cultural heritage – Guidelines for improving the energy performance of historic buildings. However, PAS 2038 states that a significance analysis should be undertaken and retrofit proposals should be measured against the impact that they have on significance by undertaking heritage impact assessments in accordance with BS7913: 2013: Guide to the conservation of historic buildings. This is a clear improvement upon PAS 2035, but unfortunately many domestic scale non domestic buildings may not be treated in such a wise way.

Whilst great care and expertise may be adopted in the assessment of a building and in the design and development of proposals, this could all be put at risk unless there is a robust approach to ensure that the design and specification is complied with as the work is being implemented on site. PAS 2038 has a more sophisticated approach to quality management compared to PAS 2035, with the requirement for inspection and test plans, but unfortunately this is only for buildings of over 1000 square meters.

It can be argued that PAS 2038 isn’t good enough, but all such PAS’s (Publicly Available Specifications) are produced through consensus. There was greater representation of heritage experts on the panel producing PAS 2038 compared to PAS 2035, hence PAS 2038 is more robust. Ultimately, PAS 2038 should be followed, but be seen as a minimum requirement.

Professor John Edwards is a Director of Edwards Hart Consultants and Professor of Practice at the University of Wales St David. He is a member of the BSI Retrofit Standards Task Group and a member of the panel that produced PAS 2038, as well as PAS 2030 and PAS 2035. A professional member and Trustee of the IHBC and Chair of its Technical Panel

For more background see the NewsBlog

See the IHBC’s response to PAS 2038

See more on consultations

See more practice guidance on the IHBC’s ToolBox: especially the Research Notes and Guidance Notes

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