How to meet the acoustic building standards in Scotland
Posts by Russell in Building Regulations
The vast majority of the UK’s buildings are built under the minimum standards set by the Building Regulations England and Wales, simply because most of the construction work undertaken in the UK is within England, given its far greater population. However, what if you are working on projects located in Scotland?
The Approved Documents published in the Building Regulations for England and Wales do not apply north of the border – or in Northern Ireland. In Scotland, new buildings and buildings undergoing conversions or renovations must be designed and built to the performance standards set by the Building Standards Technical Handbooks published by the Scottish Government.
The core principles are the same, providing a framework covering such areas as safety, accessibility and environmental responsibility, but there are significant differences in the Scottish standards. These are regarded as more stringent in areas such as fire safety, energy efficiency, climate resilience and – importantly – the passage of sound or acoustic performance.
The section of the Scottish building standards technical handbook relating to the passage of sound and acoustic insulation is Section 5.0 Noise.
Why are Scottish acoustic building standards higher than in England?
There are a number of reasons why stricter acoustic standards apply in Scotland.
Political and cultural
The first reason, and something that has been a more significant factor in recent decades, is political. Since devolution in particular, Scotland’s policymakers have been able to pursue different policies from those adopted in England, and that has been reflected in the standards applying to buildings.
The Scottish Government seeks to take a more holistic view of health and wellbeing, and that means that its building regulations often align with broader goals in this area. Within this is an objective to ensure the negative effects of noise on mental and physical health are mitigated through building design, and this is why policymakers prioritise enhanced sound insulation in floors, ceilings and walls to deliver better living conditions, especially in dense urban environments.
Hence why the Scottish technical standards handbook applies, which covers both domestic and non-domestic buildings in accordance with the Building (Scotland) Regulations 2004.
Historical
Another reason for the higher acoustic standards in Scotland is due to the types of dwellings we see in many of the country’s larger towns and cities.
Glasgow and Edinburgh in particular have a large number of multi-storey tenements and flats, many of which were built between the mid-19th and the early 20th centuries. And in the social housing boom of the 1960s and 70s, which sought to replace many of the tenement post-war slums that had developed, the concept of accommodating large numbers of people in flats continued with the construction of high-rise and low-rise blocks.
These characterised many of Scotland’s urban areas until very recently. This is why a higher proportion of people in Scotland live in flats compared to England. According to data published by the Office for National Statistics in 2022, 36.4% of households were defined as living in flats across Scotland, compared to 21.7% in England.
Scottish construction approaches, therefore, have historically required a greater focus on sound reduction between the individual residential units in blocks of flats because they are much more common. And that knowledge, experience and best practice has also been applied to acoustics in other types of buildings, such as terraced and semi-detached houses and commercial buildings.
Climate
A final key reason why Scottish technical standards are more stringent than in England and Wales is because of the slightly colder climate north of the border. Whilst this does not directly impact on standards for the passage of sound, it does mean that Scotland’s homes are generally better insulated than south of the border, which also contributes to improved acoustic performance in walls and floors.
Key differences between English and Scottish acoustic performance standards
The table below shows how the performance standards relating to the passage of sound differ between England and Scotland.
What is most obvious is that the Scottish technical standards have stricter requirements, especially for impact sound insulation, which can make compliance more demanding. Where airborne sound is concerned, the higher the figure, the better, with the opposite being true for impact sound, where a lower db rating offers higher sound insulation.
Remember too that a 10 db reduction represents a halving of sound intensity, meaning that this level reduction would mean the level of noise we hear is cut by half.
| Criteria | England (ADE) | Scotland (Section 5) |
|---|---|---|
| Airborne Sound Insulation (walls/floors) | ≥ 45 dB (DnT,w + Ctr) for new builds | ≥ 56 db (DnT,w) for new builds |
| Impact Sound Insulation (floors) | ≤ 62 db (LnT,w) for new builds | ≤ 56 db (LnT,w) for new builds |
| Conversions | Less stringent than new builds | Reduced targets, generally stricter than England, different figures apply to ‘traditional buildings’ |
‘Traditional buildings’ is not something that applies in England and Wales. Under the Scottish standards, a traditional building is defined as “a building or part of a building of a type constructed before or around 1919 using construction techniques that were commonly in use before 1919, and with permeable components, in a way that promotes the dissipation of moisture from the building fabric.”
Achieving higher sustainability standards in Scotland
In addition to the minimum acoustic standards published in Section 5.0 Noise, developers aiming to build to Silver and Gold sustainability standards also need to take into account the enhanced performance required under Section 7.0 Sustainability.
These enhanced standards are published to encourage more sustainable development in Scotland. Within this is “quality of life”, which supports the development of homes to accommodate flexible living, working and studying patterns. And, importantly, these standards seek to offer protection from noise from adjacent buildings to higher levels than those published in Section 5.0.
As a result, the following enhanced acoustic minimum standards for separating walls and floors/ceilings apply to the higher sustainability levels:
| Criteria | Silver | Gold |
|---|---|---|
| Airborne Sound Insulation (walls/floors) | ≥ 58 dB (DnT,w) | ≥ 60 dB (DnT,w) |
| Impact Sound Insulation (floors) | ≤ 56 dB (LnT,w) | ≤ 52 dB (LnT,w) |
Post-completion testing and Robust Details considerations
Under the Scottish technical standards, post-completion acoustic testing is generally required in new dwellings and residential conversions that create two adjoining dwellings. The exception is where the Robust Details scheme is used, a version of which applies in Scotland in the same way it does in England and Wales.
The process for using Robust Details (Scotland) Ltd starts with choosing a design from their handbook, and including it within your application for a building warrant to the local authority verifier, or when submitting an amendment of a building warrant application to include the Robust Details (Scotland) Ltd. The plots are then registered with Robust Details (Scotland) Ltd prior to commencement on site and the verifier is notified by forwarding them a copy of the Purchase Statement.
Using the Robust Details (Scotland) Ltd scheme avoids the uncertainties of post-completion sound testing.
How to meet Scotland’s higher acoustic building standards
The key to creating an acoustic specification that will achieve the required performance in Scotland is early consideration of the wall or floor design, and not leave it to chance.
By partnering with Hush Acoustics to achieve your acoustic performance targets, you have the additional assurance of working with a company which was founded in Scotland prior to relocating to the north of England. That means our team has a deep understanding of how to meet the specific needs of the Scottish building industry and how to deliver the additional impact and airborne sound insulation improvements required.
Hush Acoustics offers a range of fully tested acoustic systems for timber joisted and masonry floor/ceiling and wall constructions. These are designed to provide acoustic performance ranging from compliance level, through to enhanced and superior. And where a specific level of either airborne or impact sound reduction is sought which is not covered by one of our systems, the Hush team can provide a bespoke solution, either by adapting one of our systems or creating a completely new design and specification.
In addition, Hush systems are approved for use under the Robust Details scheme which can eliminate the need for post-completion testing in new build projects.
