The Air Tightness Testing and Measurement Association (ATTMA) is proud to have officially responded to the Scottish Government’s consultation on proposed changes to energy and environmental standards for new buildings. This consultation is a vital step towards creating a Scottish equivalent to the internationally recognised Passivhaus standard. The move is a bold and necessary one in response to Scotland’s ambition to lead the way in climate-conscious, energy-efficient construction. Scotland’s new-build regulations are set to transform the energy landscape, driving sustainability and reducing emissions while enhancing occupant comfort and air quality.

The consultation, which was launched in July 2024, invites industry professionals, trade associations, and the public to provide feedback on a proposed Scottish building standard that aims to match the rigorous energy efficiency and environmental performance of Passivhaus. The goal is to further enhance building fabric standards, airtightness, and ventilation systems, ensuring that new buildings are healthier, more energy-efficient, and capable of contributing to the nation’s 2045 net-zero targets.

The Goals and Intentions of the Consultation on Energy and Environmental Standards

The consultation sets out to create building regulations that improve the energy efficiency and environmental performance of new builds in Scotland. This is in response to the climate emergency, Scotland’s commitment to the Climate Change Act, and its ambitious targets to reduce greenhouse gas emissions to net-zero by 2045. With Alex Rowley MSP’s 2022 Bill Proposal as the driver behind the consultation, the Scottish Government is looking to introduce new minimum environmental design standards for all new-build housing. These standards will be based on the core principles of Passivhaus, a voluntary standard that has set the benchmark for energy efficiency for over 30 years.

The intention is clear: the Scottish Government wants buildings that need less energy to operate, that are healthier for occupants, and that can assure compliance with standards in practice. The Passivhaus standard achieves these goals by optimising building form and design, ensuring highly insulated and airtight buildings with low energy demand, and maintaining consistent indoor air quality and comfort levels. The Scottish consultation seeks to adapt these core principles into its own building regulations, making them deliverable at scale across the country.

The consultation is structured around several key proposals, including:

> Defining a Scottish equivalent to the Passivhaus standard
> Tightening the requirements for building fabric, insulation levels, thermal bridging, and airtightness
> Mandating the use of mechanical ventilation systems to ensure proper air quality
> Establishing clear metrics for energy efficiency, with a focus on reducing the space heating demand of buildings
> Strengthening the compliance process to ensure that new builds meet these standards in practice

ATTMA’s Response and Key Recommendations

ATTMA’s response to the consultation focuses on two core areas: airtightness and ventilation. As the certifying body for air tightness testing in the UK, ATTMA has a significant interest in ensuring that the future of Scotland’s construction standards reflects the best practices in air tightness testing and building performance.

ATTMA has long advocated for stricter airtightness standards to be applied to all new builds. In our consultation response, we highlight the importance of building homes to much higher airtightness levels than currently required. This not only reduces energy demand but also helps in maintaining indoor air quality and comfort. Buildings that leak air will always require more energy to heat or cool, leading to higher running costs and increased emissions. The proposal for a Scottish equivalent to Passivhaus would place a much-needed focus on achieving near-zero air infiltration, making buildings far more energy-efficient and comfortable.

In our response, we also have emphasised that the established blower door method remains the gold standard for air tightness testing, ensuring that compliance is measured accurately and consistently.

Furthermore, ATTMA stresses the necessity of mandatory, continuous mechanical ventilation systems in all new builds. As fabric standards are improved and air leakage is reduced, the risk of ventilation-related issues, such as poor air quality, mould, and the build-up of airborne toxins, becomes a serious concern. In our response, we call for an end to the reliance on ‘natural’ ventilation methods, such as trickle vents, which are insufficient for maintaining indoor air quality in highly insulated and airtight homes. Instead, we advocate for a shift towards continuous running mechanical ventilation as a minimum requirement, ensuring that all new homes are properly ventilated to protect the health and well-being of occupants.

We also highlight the need for an independent commissioning process for ventilation systems. With airtightness becoming an increasingly important factor in energy-efficient design, it is crucial that ventilation systems are installed and tested by competent, independent third parties. This will ensure that systems are operating as designed and that indoor air quality standards are met. The consultation presents a golden opportunity for Scotland to lead the way in construction practices, and ATTMA is committed to supporting these vital improvements.

What’s Next: Timeline for the Delivery of New Standards

The consultation process runs until 23rd October 2024, after which the Scottish Government will review the responses and take them into consideration as they prepare for the second stage of the review. The aim is to finalise the proposed changes to the building standards and present them in a further consultation in summer 2025. By December 2024, the government intends to lay down the necessary regulations to implement the first stage of these new standards. The revised standards are expected to come into force shortly after, making Scotland a pioneer in setting some of the most ambitious construction regulations in the Western world.

The second consultation, planned for mid-2025, will focus on refining the detailed proposals and developing the guidance tools and compliance frameworks necessary to implement the new standards. This will include further discussions on energy performance metrics, compliance verification, and how the new standards will be applied across different building types.

Scotland’s approach to energy efficiency and environmental standards could set a new benchmark not just in the UK, but internationally. The nation’s commitment to creating a Passivhaus equivalent standard, adapted to its own unique building environment and climate, represents a significant shift towards a future where all new buildings are designed and built with sustainability, efficiency, and occupant health at their core.

A Word from Barry Cope, Group Managing Director of ATTMA

“We are extremely supportive of the Scottish Government’s efforts to improve their building standards, particularly in adopting a Passivhaus-equivalent approach to new builds. Scotland is taking brave steps towards creating some of the best construction standards in the Western world. It’s no small feat to set such ambitious goals for energy efficiency, airtightness, and ventilation, but it’s necessary if we are to tackle the climate emergency and provide homes that are healthy, comfortable, and affordable to run.

The consultation process is a critical opportunity for the construction industry to shape the future of building standards in Scotland, and we’re proud to be a part of it. By improving airtightness and ensuring robust, independent commissioning processes for ventilation systems, we can make a real difference in how buildings perform in practice, and we look forward to seeing these changes implemented in the near future.”

The Future of Scottish Building Standards

The changes outlined in the consultation represent a monumental shift towards a more sustainable and energy-efficient built environment. With an emphasis on airtightness, ventilation, and rigorous compliance processes, Scotland is poised to set a new standard for building performance. ATTMA’s role in responding to this consultation reflects our ongoing commitment to promoting best practices in air tightness testing and ensuring that new-build homes are built to the highest standards.

As the consultation progresses, ATTMA will continue to engage with the Scottish Government and other stakeholders to support the development and implementation of these new regulations. We are excited to see the positive changes that these new standards will bring, not only for the construction industry but for the people of Scotland as they benefit from healthier, more energy-efficient homes.