Scotland to accept passive house as regs compliant

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Scotland’s devolved government has published amendments to building standards which are set to usher in a transition to the passive house standard – including the development of a local equivalent to the standard, and recognition of passive house certification as an alternative means of meeting compliance.

The amendment, laid by the Scottish parliament on 12 December, makes concrete a December 2022 commitment made by ministers to give effect to the ‘Domestic Building Environmental Standards (Scotland) Bill’, first proposed by Alex Rowley, a Labour member of the Scottish parliament, in May of that year.

The Building (Procedure) (Scotland) Amendment Regulations 2024 introduces a requirement for developers to provide an “energy and environmental design statement” with building warrant applications and an “energy and environmental construction statement” with each completion certificate.

A date of 31 March 2028 has been set for implementation. The move to amend building regulations followed an initial consultation held in the summer of 2024, with a second round of consultations due in 2025 to set out proposals for the revision of performance targets, and for compliance requirements and supporting processes. The revised standards are set to be published in early 2026 and become mandatory in early 2028.

One element being considered for the Scottish passive house equivalent definition is an energy use intensity (EUI) target, which may differ depending on building types. EUI refers to the amount of energy used annually per square metre of floor area and typically includes all energy use at the meter – including so called ‘plug loads’, or unregulated energy. Focusing on an EUI target would mean that the definition would include hard targets for the energy efficiency of the building itself, rather than relying on ‘primary energy’ targets – meaning the energy used at source, such as the power station. As less efficient electricity generation is phased out, the primary energy of the grid is improving. This means, in the case of electrically heated buildings, that primary energy-based targets may give the false impression of energy efficiency, lower running costs and higher thermal comfort, and risk undermining public confidence in attempts to decarbonise buildings.

A statement issued by Scottish Building Standards described the move as “an important milestone in the current review of building standards,” and said engagement with its working group and wider industry partners was now needed to agree the extent to which the ethos and components of the passive house standard can be embedded within performance targets are defined and how compliance, and the real-world performance of new buildings, is assured. The move has been given a guarded welcome by the UK’s Passivhaus Trust.

Sarah Lewis, the trust’s research and policy director said the Scottish government’s announcement was an “important first legislative step”. However, the trust was nevertheless “still awaiting the fine details of what that policy will look like. We are hopeful that the recommendations we put forward in our consultation response will have been taken on board so that Scottish building standards have the accurate tools and absolute energy targets that would be essential for any standard aiming to be a passive house equivalent".

The trust stressed the importance of setting absolute energy targets in the new standard being set close to passive house levels, a modelling tool with accuracy equivalent to PHPP (Passive House Planning Package), and the need for training to up-skill the industry as needed.

“Everything is still up for grabs in terms of targets," said Passivhaus Trust CEO Jon Bootland. "We’re very supportive of the move towards absolute targets, and also of mechanisms to ensure greater certainty of actual performance for building occupants."