Building regulations - proposed changes to energy standards, etc: consultation analysis

Executive Summary

Background

The Scottish Government’s ‘Heat in Buildings Strategy’ (2021)^[1] sets out its vision for decarbonising heat and reducing energy demand across all buildings in Scotland, setting out the scale of the investment opportunity and supporting our green recovery from the Covid-19 pandemic.

Reviews of the energy standards within building regulations undertaken in 2002, 2007, 2010 and most recently in October 2015 has resulted in a stepped reduction in carbon emissions associated with the use of new buildings.

This consultation sought to deliver further improvement to the energy efficiency of new buildings and new building work, in line with the Scottish Government’s wider net zero ambitions. It also sought views on additional areas: ventilation; overheating risk; compliance and electric vehicle charging.

Seven draft guidance documents were issued in support of the consultation.

The consultation opened 26^th July 2021 and closed on 28^th November 2021. The consultation was originally due to close on 29^th October 2021, but the deadline was extended in response to requests from key stakeholders.

The consultation paper included 79 questions, the majority of which were closed questions. Respondents were also asked to add commentary to provide context to their answers. There was no word or page limit, enabling respondents to provide as much detail as they chose. In total, 176 responses to the consultation were received, via an online survey hosted on the platform ‘Citizen Space’. Most of the responses (89%) were received from organisations and the remainder (11%) from individuals. Most of the respondents were ‘industry associations/manufacturers’ (24%) followed by ‘contractor/developer’ (14%). The base number of responses varies by question.

The response to the consultation was generally positive. Key messages are presented below, grouped by the separate parts of the consultation.

Overview: Part 2 – Energy, new buildings

This section of the consultation covered the process of demonstrating compliance of a new building with standard 6.1 of Building Regulations via the application of the SAP or SBEM calculation methodology. It addressed the process of setting and meeting performance targets under that standard.

Key messages: Energy, new buildings

There is strong support for the introduction of an energy target for new buildings in addition to current emissions targets, notably for a primary energy target. This is underpinned by strong emphasis on the adoption of a fabric first approach. However, it was also noted that basing the target on a SAP will be strongly reliant on the provision of adequate SAP software to calculate and cost effectively.

There is clear support for an uplift to the 2015 standard for new dwellings, with slightly more respondents (42%) in favour of Option 2 – an ‘advanced’ standard equating to a 57% emissions reduction than those respondents in favour of Option 1 (38%) – an ‘improved’ standard equating to a 32% emissions reduction.

The improved standard is considered to be adequate and more achievable than the advanced standard. Those in support of the advanced standard welcome the concept of a ‘more aggressive’ target to tackle climate change and a transition towards low and zero carbon. However, some concerns were flagged in relation to capacity to achieve an advanced standard, which on a positive note was deemed ambitious, but on the basis of that ambition, potentially unviable.

There is strong support for the overarching concept of an uplift to the 2015 standard for new non-domestic buildings. Nearly two-thirds of respondents (63%) support a ‘high’ standard, equating to 25% emissions reduction. A fifth of respondents are in support of a ‘medium’ standard, equating to 16% emissions reduction. More respondents are in favour of the high standard as they deem it to be achievable, while remaining an ambitious target. Again, the importance of a fabric first approach is emphasised.

A range of comments were made about values identified for the elements which make up the Domestic Notional Building Specification. These mostly relate to meeting the proposed values in practice and any unintended consequences of doing so. More time was requested to both develop and test technical solutions to address the challenges.

In relation to the values identified for the elements which make up the Non-domestic Notional Building Specification, most considerations related to glazing, with some concerns flagged around the achievability of the proposed changes in the timescales. However, it was also suggested that the proposed standards were not sufficiently ambitious and could go further, i.e., there is a lack of consensus.

Respondents in support of a simplified two-specification approach to defining the domestic notional building point to increased flexibility and a transition away from fossil fuel heating systems. Many respondents found it difficult to comment, stating that this was because of perceived issues they associate with the currently available SAP software.

There is also support for the simplified two-specification approach for non-domestic notional buildings. Where respondents were not in favour, several reasons were cited including a preference for all buildings to be assessed against the same heating systems.

In relation to the proposal to provide a more demand-based approach to assignment of domestic hot water heating within the non-domestic notional building specification, there is support on the basis that this is appropriate where there is low demand. More clarity is requested on water consumption figures.

There is strong support for a change in the application of targets for supplied heat connections for new buildings, with 86% of respondents in favour.

The vast majority of respondents (81%) agree that benefits from on-site generation within the compliance calculation should be limited by a practical assessment of the extent that generated energy can be used on site. Over half of the respondents (55%) report no concerns about the approach to limited benefit from on-site generation of power, with regard to particular technologies or solutions.

Nearly two-thirds of respondents (61%) agree with a proposed approach for new buildings to be exempt from the need for a calculation to demonstrate compliance with the Target Emissions Rate - where heat demand is met only by ‘zero direct emissions’ sources. Those in support of the proposal commonly refer to benefits they perceive from simplification of the design and assessment processes.

There is clear support for the need for new buildings to be designed to enable future adaption relating to use of zero direct emissions heat sources (where not initially installed), with 81% of respondents agreeing. There is a desire for clarity as to what exactly constitutes simple future adaption, which would help to inform the type and level of detail of information required to be made available to homeowners seeking to action the change.

Substantial support (91% of respondents in agreement) was expressed for the proposal to retain the current elemental approach to setting minimum standards for fabric performance in new dwellings. Where required, there will be an option to take an alternative approach via calculation of the total space heating demand for the dwelling. Those in support commonly refer to simplicity, flexibility, and familiarity in terms of their reasoning.

Respondents were asked to make comments on the maximum U-values proposed for elements of fabric, in relation to their level of challenge and achievability at a national level. The availability of products, product development and potential related safety issues were flagged in response. Specific concerns were raised on behalf of the aluminium fenestration industry and in relation to the requirements for windows and doors and, triple glazing.

There is considerable support for the proposal to move to airtightness testing of all new dwellings, by registered members of an appropriate testing organisation (86% of respondents in agreement).

There is also substantial support for the adoption of CIBSE TM23 as the basis for airtightness testing in Scotland (93% of respondents in agreement). Many comments highlight that it would be practical for Scotland to adopt the same principles and standards to align with the rest of the UK.

There is strong support for the introduction of the pulse test method of airtightness testing as a further means to testing and reporting on the performance of new buildings, with 83% of respondents in agreement. Again, respondents pointed to the advantages of a consistent approach across the UK.

Respondents were asked to comment on the amended provision for modular buildings (non-domestic). The majority of respondents (89%) state they believe that this provides an appropriate balance between multiple requirements relating to improvement of building energy performance, reuse of modular elements and use of small units for short-term use at short notice.

Overview: Part 3 – Energy, all buildings

This section of the consultation introduced proposed changes to provisions which apply to new buildings and to new work to existing buildings. This included proposals for improved minimum standards for building fabric and a simplification of how these are applied across new and existing buildings.

Key messages: Energy, all buildings

There is clear support for the proposed introduction of the term ‘major renovation’ as further means of identifying when aspects of building regulations should apply to existing buildings – 89% of respondents are in agreement, stating renovation is an appropriate point to consider what types of energy performance improvements can be made.

The proposed improvement in maximum U-values for elements of building fabric for domestic buildings is supported by 70% of respondents. Most respondents emphasise the need for fabric first approach as a critical enabler in reducing greenhouse emissions.

There is also strong support for this proposal in relation to non-domestic buildings (80% of respondents in favour). Respondents note that non-domestic and domestic standards should be similar. Although some respondents note that proposed U-values are ambitious, they believe them to be achievable in light of current technology and skills.

There is considerable support for the standardisation of values and approach for conversions, extensions, and shell buildings (81% of respondents in favour). Respondent comments refer to such standardisation as sensible, providing clarity and a better understanding of requirements.

Respondents were asked to comment on the presentation of information on compliance of building services. Nearly half (44% of respondents) express a preference for re-integration of guidance into the relevant standard. Around a quarter of respondents (24%) suggest Compliance Guides should move to Section 6 as an Annex. Just over a fifth of respondents (22%) propose retention of separate Compliance Guides. While there is no one clear consensus on the presentation, there is a common desire for having information easily accessible from the same place.

There is very strong support for continued alignment of minimum provisions for fixed building services at a UK level within the Domestic Building Services Compliance Guide (92% of respondents in agreement).

There is further support for changes to the Non-domestic Building Services Compliance Guidance (89% of respondents agree with proposed changes).

Support was also expressed for the proposal to limit distribution temperatures in wet central heating systems to support effective implementation of low and zero carbon heat solutions and optimise the efficiency of heat generation and use. Respondents described this as a sensible approach, given its scope to provide energy and cost savings - with 88% of respondents in agreement with the proposal.

The majority of respondents support extension of provision of self-regulating devices to include installation (where absent) at the point a heat generator is replaced. Respondents described these measures as reasonable and proportionate, with 94% of respondents in favour.

There is further support for the proposal to introduce a requirement for building automation control systems, of the type specified, in larger non-domestic buildings with systems with an effective rated output over 290 kW. Most respondents felt this could result in greater energy efficiency, user benefits and cost savings (87% of respondents in agreement). It should be noted that there was notable divergence on the 290 kW threshold, with questions raised as to how the threshold had been determined and why it was high.

Overview: Part 4 - Ventilation

Following the commissioning of research into the impact of previous 2015 ventilation amendments to ventilation standards for new homes in 2021, it is the intent of BSD to undertake a fuller review of ventilation provision for both domestic and non-domestic buildings from 2022. Accordingly, changes proposed are focused on domestic ventilation and are limited to those which are considered to be directly relevant to the introduction of improved energy standards or (in response to published research) can better address the delivery of expected levels of ventilation and good indoor air quality.

Key messages – ventilation

There is considerable support for proposed revisions to presentations of guidance on ventilation and incorporation of the 'domestic ventilation guide' into the Technical Handbooks. Respondents note that this will provide greater clarity with improved accessibility and awareness (93% of respondents in favour).

There is also very strong support to revise guidance in order to clarify the function of purge ventilation and increase provision to align with that applied elsewhere in the UK. Respondents believe alignment with the rest of the UK would enhance simplification and reduce confusion (97% of respondents in favour of the proposal).

Three-quarters of respondents agreed with reference to a single option for continuous mechanical extract ventilation which can have centralised or decentralised fans, with the same design parameters being applied to the system in each case. There is further support for proposed guidance on default minimum size of background ventilator for continuous mechanical extract systems (89% of respondents in agreement).

Nearly two-thirds (60%) of respondents agree that continuous mechanical extract systems be considered a viable solution in very low infiltration dwellings. Most respondents felt this would be a viable option for low infiltration dwellings. Respondents who did not agree most commonly pointed to the consequences of failure when reliant on a single fan.

Seventy per cent of respondents were in favour of mandating heat recovery systems, pointing to benefits of a reduction in energy consumption and subsequent carbon emissions.

There is overwhelming support for the proposed incorporation of a revised version of the current 'domestic ventilation guide' as an annex to section 3 (environment) of the Domestic Technical Handbook (95% of respondents in agreement). Respondents emphasised the need for documents to be electronic, fully indexed and referenced.

Respondents invited to provide additional comments referred to the necessity to harmonise energy and ventilation standards.

Overview: Part 5 – Overheating risk in new dwellings and other new residential buildings

In the consultation document, the BSD proposed that any new provision to assess and mitigate against the risk of summertime overheating should apply to all new dwellings, subject to the application of a set of trigger criterion that determine the need to consider the design and specification of the dwelling further to mitigate such risk.

It was also proposed that the same assessment be applied to non-domestic residential buildings where the built form and occupancy is similar to dwellings (e.g., self-contained student flats accessed off a common area).

Key messages – Overheating risk in new dwellings and other new residential buildings

The majority of respondents (85%) agree with the proposed introduction of a requirement to assess and mitigate summertime overheating risk in new homes and new non-domestic residential buildings offering similar accommodation. The main reason cited was climate change, with many respondents also flagging risks to health and welfare associated with overheating.

There is very strong support (96% of respondents in agreement) for an initial assessment of dwelling characteristics to be undertaken to help inform design choices and the delivery of new homes which provide better thermal comfort in the summer months.

Respondents broadly agree with assessment proposals as a suitable means of mitigating summertime overheating in new homes through prescriptive actions. Overheating risks are clearly a key consideration, 79% of respondents agree with the proposal.

Respondents were asked whether the proposed standard and guidance will provide adequate assurance that ventilation measures provided to mitigate summer overheating can be used safely and conveniently in practice. While the majority of respondents (83%) stated their agreement, a number of factors were cited that might limit the extent to which building occupants use the mitigation measures.

Overview: Part 6 – Improving and demonstrating compliance

In late 2019, BSD commissioned a short research project to assist in understanding the issues that arise in the delivery of low energy buildings and how greater assurance of process could be delivered, focusing primarily on building fabric issues. The output of the project was not intended to be a guide for designers and contractors but to inform the later development of such a resource.

BSD stated its intention in the consultation to progress this agenda, extending scope to include the design, installation, and commissioning of building services, in the context of the Compliance Plan approach. BSD will commission the development of a ‘compliance manual’ to support effective delivery of compliance with Section 6 (energy) in a format which would be compatible with the Compliance Plan approach and supporting core guidance.

Key messages – Improving and demonstrating compliance

Respondents gave details of processes for National House Building Council (NHBC), Passivhaus and the Structural Timber Association, alongside references to technical guidance documents, that they felt would be useful for the development of a Compliance Plan manual. Respondents broadly acknowledged difficulties associated with assurance of compliance, and made further reference to the need for competence and skills requirements for various roles involved in the compliance process, from Compliance Manager to tradespeople.

Overview: Part 7 – Electric vehicle charging infrastructure

The Scottish Government is committed to the decarbonisation of transport and with demand for Electric Vehicles (EVs) expected to grow rapidly, enabling people to switch to zero emission vehicles, will require ready access to convenient and reliable EV charging infrastructure.

This part of the consultation sought views on the Scottish Government’s preferred policy options relating to the installation of EV charge points and enabling infrastructure (namely accessible trunking, conduits, or cable trays for electricity cabling) to facilitate the future installation of EV charge points in the car parks of residential and non-residential buildings.

Key messages – Electric vehicle charging infrastructure

Overall, respondents were supportive of the proposals to enable the installation of electric vehicle (EV) charge points and ducting infrastructure (to facilitate the future installation of EV charge points) for parking spaces in new residential and non-residential buildings parking. However, concerns were cited in relation to the costs of installation of the charging points and associated infrastructure.

Respondents are largely positive about preferred options for EV provision in new and existing buildings, but there are concerns as to the level of ambition of the proposal, with costs again being the primary issue. Respondents questioned who will be liable for upfront and future maintenance costs. Most respondents requested more detail and clarification as to how the preferred options would operate in practice.

There is clear support for the Scottish Government’s preferred options for the exemptions as set out in section 7.6.1 (82% of respondents in agreement). Again, however, respondents are seeking greater clarification as to how this would work in practice, as is also the case for the preferred option relating to existing non-residential buildings with car parks with more than 20 spaces.

Overall, respondents are supportive of proposed provision for charge points for accessible parking spaces.

Final comments in relation to EV charging provision re-iterated questions raised about costs, notably a lack of clarity as to what the costs would be and liability for payment.