It’s one thing to acknowledge climate change; it is quite another to take practical steps that will make a difference. The introduction of reasonable levels is a particular challenge for the UK for historical reasons: over 50% of the housing stock was built before the 1965 Building Regulations brought in introductory regulations governing insulation.
Home dwellings account for 14% of greenhouse gas emissions. Meeting the ambitious net-zero target for emissions by 2050 (UK), 2045 (Scotland) is going to require shrinkage of heat emissions by 95 per cent. This figure looks even more daunting when considered in terms of CO2 tonnage. Because that’s a reduction from 2,345 Kg (current) to 138 Kg, that’s a challenge.
The size of this challenge is truly overwhelming. There will need to be a concerted effort to increase the energy efficiency of all homes. However, this is small potatoes compared to the vast retrofit programme that will be required—something that has never been attempted before. Given that such a programme will involve every single dwelling in the country, it isn’t surprising. Contractors have their work cut out to plan how this work could be carried out.
Of course, standards must be defined to guide the retrofit work, which is why the UK Government brought in a Retrofit Standards Framework, specifically to prevent piecemeal implementation of so significant a change. In effect, the government have set out three logical steps for the industry:
- Carry out a property by property assessment of each property
- Produce a medium-term plan of action
- Introduce approved measures
What is PAS 2035 and what does it mean?
PAS 2035 is the key document. It sets out clear guidelines for contractors by offering a procedure for building assessment, a guide to selecting the most appropriate EEMs and instructions for long-term monitoring. The document also lays down minimum standards of qualifications, roles and responsibilities, for anyone carrying out retrofitting. The updated PAS 2030 can be seen as a companion to PAS 2035 since it focuses exclusively on commissioning, installation and hand over of EEMs.
Before 2015, unease grew concerning a perceived gap between energy efficiency promised and energy efficiency delivered and at the end of 2016, the Bonfield review was published. This report laid down 27 primary recommendations and suggested a brand new approach to retrofit projects which was to be underpinned by the introduction of a Home Quality Mark in addition to new codes of conduct and practice. The review also proposed a cradle-to-grave framework for the delivery of retrofit energy efficiency.
Efforts have been made by the UK government in tandem with an appointed implementation board, to put the review’s recommendations into effect.
In terms of quality assurance, an extension to the existing quality mark to encompass repair, maintenance and improvement, retrofits and energy efficiency sectors. This opens up a future in which retrofit schemes may be entered into only by TrustMark-registered companies.
In common with other such schemes, companies seeking accreditation will need to be formally assessed by a qualified certification body. Recently the government adopted three new requirements:
- PAS 2030:2019 – Specification for the installation of energy efficiency measures in existing dwellings and insulation in residential park homes
- PAS 2031:2019 – Certification of energy efficiency measure installation in existing buildings and insulation in residential park homes
- PAS 2035:2019 – Retrofitting dwellings for improved energy efficiency. Specification and guidance.
Collectively, these specifications offer a thorough framework for energy efficiency retrofits on domestic properties. Companies should start now, to familiarise themselves with these specs—by 30 June 2021, it will be mandatory for certification bodies and companies registered under the TrustMark scheme to comply with them. As is the case with any robust system, compliance will need to be evidenced.
PAS 2035 – A whole-house approach
The third document listed above—PAS 2035:2019—offers the most comprehensive understanding of the entire Retrofit Standards Framework. Everything from assessment, design and monitoring is explained. PAS 2035 takes a pragmatic, so-called ‘whole-house approach,’ in recognition of the fact that there is no solution set that will fit all circumstances. This way, all aspects of the property require careful, holistic evaluation in advance of any EEMs being put in place. The ‘whole-house’ approach further recognises that insisting that all features are raised to an identical high standard is not only impractical but ill-advised.
PAS 2035 covers risk assessment and whole-dwelling assessment. This process encompasses:
- Building construction
- Architectural character
- Patterns of use
Considering how retrofitting may impact on each. PAS2035 adopts a philosophy that raises considerations such as the protection of occupant health, wellbeing and comfort above those of merely upgrading the energy efficiency of the property.
- Medium-term planning aims to determine a suitable improvement level, given any constraints. At the end of this period of consideration, the idea is to deploy a collection of EEMs.
- Plans should include a review of unintended consequences arising from potential interactions between EEMs.
- A precise order in which EEMs are to be deployed must also be included, with consideration given to any knock-on effects.
- Plans must be formatted in a future-proof way, to facilitate inevitable changes.
A cost-effective method of improvement, emphasised in PAS2035, is the fabric first approach, which is both robust and cost-effective—an approach PAS2035 suggest should be taken into account in the planning process. Essentially, this means taking the following sequential steps:
- Upgrade the building to a reasonable state of repair concerning pointing, brickwork integrity and damp
- Replace older light fittings with low-energy bulbs and lighting units.
- Improve temperature controls
- Tackle more significant, possibly more costly upgrades to the fabric of the building, e.g. by installing insulation, thermal bridge/air leakage reduction, installing ventilation.
Actual scopes of work evolve from issues noted in the first building assessment. For example, contractors may be restricted in the range of work that can be carried out on listed buildings. In the same way, a risk-based approach is preferred for older properties.
Poor decisions taken in the design phase can significantly reduce effectiveness. For this reason, PAS2035 singles out the need to ‘concentrate on the interfaces’. This ensures that junctions are watched closely to make sure insulation layers and air barriers are continuous and thermal bridges dealt with effectively.
When this has been achieved, contractors can concentrate on residual heat and energy requirements and dealing with them as effectively as possible. This includes which renewable technologies are appropriate.
PAS 2035 facilitates best practice by offering guidance on methods for monitoring and evaluating properties and by considering ways that feedback from one project can be made available to others, for continual improvement.
An essential facet of PAS 2035 is that it seeks to give a voice to occupants, putting their views front and centre of the refurbishment process. This certainly inspires consumer confidence, but it also acknowledges that occupant use is capable of undermining the effectiveness of EEMs, and even exacerbate the performance gap between the designed and actual performance of the building. An instantly recognisable example of this phenomenon is when occupants living in highly insulated and airtight buildings leave windows open while running heating systems.
PAS 2035 goes further with consultation by ensuring that occupants are kept informed of all developments in improvement plans relating to their properties. Updates are reasonably comprehensive, providing as they do, details about how interventions operate and explanations why they were scheduled in a specific order. Data is also provided to ensure that post works, energy efficiencies achieved during the retrofit are maintained over the longer term.
In support of the Retrofit Standards Framework, an online data warehouse has been created. This enables the logging of work at one location and makes it available to other sites in real-time, facilitating an integrated approach. More value has been created with the introduction of a property hub that provides a window to view useful information for homeowners.
Roles and responsibilities
As a means to validate competency, several pivotal positions have been created within the Retrofit Standards Framework. PAS 2030 and PAS 2035 set out clear and mandatory vocational or professional qualification requirements. In reality, individuals may hold any number of posts simultaneously. As a check on this flexible arrangement, post holders must be sufficiently qualified, and any potential conflicts of interest must be made visible from the outset.
Of all roles, that of Retrofit Coordinator has primacy. The person in this role has responsibility for end-to-end project oversight. The Retrofit Co-ordinator:
• Commissions measure design
• Contracts installers
• Acts as the homeowner’s advocate
It does not matter who employs the Retrofit Coordinator. The client can do this, or any other party for that matter, so long as he or she is responsible for protecting the client and the public’s interest, and for ensuring compliance with PAS 2035.
PAS 2030 and PAS 2035 set out a series of well-defined steps through which all retrofit projects should proceed:
A conversation takes place between the Retrofit Adviser and the householder. The plan includes reducing consumption, through property improvements and adjustments to occupant behaviour.
The householder has the option to explore a range of improvements. If this exploration is taken up by the householder, the retrofit coordinator conducts a risk assessment informed by the contents of various key documents:
• Current Energy Performance Certificates
• Interviews with occupants and or owners
• Site visit observations
From these inputs, each property is graded A (lowest) to C (highest), and this grade will determine the future trajectory of the project. The risk assessment is repeated and updated as new measures are implemented.
Retrofit assessors carry out a whole-dwelling survey, to include a comprehensive review of:
• The property’s heritage, construction and dimensions
• Current services
• Defects and improvement opportunities
• Existing planning constraints
• Moisture properties and suitability for improvement.
For risk paths B and C, further considerations are required, including:
• Occupant appraisal. Have they special requirements?
• Ventilation review
• Air permeability assessment
• Yearly fuel consumption and estimated emissions
• A significance estimate following BS 7913:2013 which is a guide to the conservation of historic buildings.
The retrofit designer now considers all the data collected and sets about designing a bespoke package of EEMs, paying close attention to fabric EEMs and to measures that might potentially interact. If dealing with risk paths B or C, the retrofit coordinator must include an improvement option evaluation before completing the retrofit design, calculating payback period and carbon cost-effectiveness.
At this stage, the retrofit coordinator sets out a twenty to thirty-year improvement plan, in which improvements are sequenced to achieve the optimal long term benefit of the owner. Close attention to sequencing has a further advantage: designer needs to ensure that one measure does not hamper another.
Improvement plans are discussed with the customer, including any required statutory approvals. Following from this retrofit installers receive briefings on design, sequencing new technologies.
PAS 2030 guidance is used to inform the installation of EEMs by retrofit installers. Responsibility for compliance lies with the installer, who must also supply evidence.
The retrofit installer monitors testing and commissioning of EEMs.
The retrofit coordinator assures an effective handover to the occupant or owner of the property. The transfer will include an on-site inspection and clear safety information, care and maintenance. The coordinator retains testing certificates, commissioning records and other paperwork, giving the client access. They will also suggest creating a new EPC and undertaking any further work arising.
At this stage, the role of retrofit evaluator comes to the fore. PAS 2035 requires the evaluation of retrofit projects, and the retrofit evaluator may have to monitor the site over time to confirm if expected outcomes have been met. And also, of course, to provide feedback to the whole supply chain.
The retrofit evaluator visits homeowners, no later than three months from handover, to carry out a brief questionnaire evaluation. This seeks to confirm whether expected outcomes from the previous work have been achieved. At this point, homeowners may register complaints or dissatisfaction.
If any interested parties conclude that there has been a significant shortfall in performance, two possibilities open up: intermediate and advanced. Such additional steps may include:
• Airtightness testing
• Fuel use metering
• Thermographic survey
Intermediate measures must be carried out within six months of handover; advanced measures within two years. The retrofit evaluator circulates recommended remedial actions.
TrustMark-registered business deadline
As referred to above, a transitional period—valid until 30 June 2021—has been introduced to allow firms time to reach the required standard and gain certification. Companies intending to trade under the TrustMark scheme must be certified to and compliant with PAS 2030 by the deadline.
As the Retrofit Standards Framework transitions responsibilities out of PAS 2030:2019, registered companies must also be able to prove compliance with PAS 2035, following certification.
The big picture
Upgrading homes to improved energy efficiency standards presents a massive task—and opportunity to today’s construction industry.
The Retrofit Standards Framework offers a clear and systematic approach to this work. In adopting this approach, industry professionals can be sure they are ready for the challenges of delivering retrofits that meet expectations and provide value to homeowners in the long-term.