Acoustic Design Standards for Educational Buildings – A Country-by-Country Guide
A country-by-country guide for architects working across Sweden, Norway, Denmark, the UK and Poland.
Good acoustics in schools is not a luxury specification- it is a precondition for learning. Yet the standards that govern acoustic performance in educational buildings vary significantly from country to country: different metrics, different threshold values, different enforcement mechanisms, and different relationships between voluntary classification and mandatory regulation. For architects working across markets, navigating this landscape is both essential and time-consuming.
This guide maps the key acoustic standards for educational buildings in five of Gustafs’ core markets: Sweden, Norway, Denmark, the United Kingdom and Poland. For each country we cover the governing standard, what it requires, how it is enforced, and what it means in practice for the specification of wall and ceiling treatments.
Why acoustic performance in schools demands its own framework
Classrooms, libraries, lecture halls and corridors present acoustic challenges that differ fundamentally from offices or healthcare settings. The primary goal is speech intelligibility – the ability of students to clearly hear and process what a teacher says, at varying distances, in the presence of background noise generated by the students themselves.
Three acoustic parameters dominate educational design: reverberation time (RT or T60), background noise level, and sound insulation between adjacent spaces. Underlying all three is a fourth, often under-specified parameter: signal-to-noise ratio (SNR) – the difference in level between the teacher’s voice and the background noise at the listener’s position. Speech intelligibility is ultimately governed by SNR; reverberation control and background noise limits are both means to that end. These parameters interact: a room with well-controlled reverberation but inadequate sound insulation from an adjacent music room will still fail to support learning. Similarly, a classroom meeting its reverberation target may still underperform if ventilation noise pushes background levels above 35 dB(A).
Research consistently points to a target reverberation time of around 0.4–0.6 seconds for unoccupied classrooms as the optimal range – the precise figure depends on room volume, the age of learners, and whether the space serves language instruction or general teaching. Most national standards in Europe have converged toward 0.6 seconds as the maximum acceptable value, though the routes to compliance, and the ambition of the best-practice tier, differ considerably.
Beyond the headline numbers, there is a growing recognition that acoustic standards need to account for neurodiversity, hearing impairment, and language learning – populations for whom the standard requirements are necessary but not always sufficient. We address this in a separate article on designing for neurodiversity.
Sweden – SS 25268:2023
The Standard
Sweden’s primary standard for educational acoustics is **SS 25268**, maintained by the Swedish Standards Institute (SIS). The most recent edition, SS 25268:2023, was introduced in April 2023 and covers healthcare premises, rooms for education, preschools and leisure-time centres, offices, hotels and restaurants.
The 2023 revision made a significant structural change: it replaced the previous sound classification system of classes A to D with two new requirement levels — Basic and Enhanced — with an increased focus on the acoustic needs of rooms rather than their name or category. Educational facilities are now treated as a single segment, no longer divided into higher and lower education.
What it requires
The standard sets requirements across five areas: airborne sound insulation, impact sound levels, indoor noise from installations, indoor noise from traffic, and room acoustics (reverberation time).
A notable addition in the 2023 edition is a stronger focus on low-frequency absorption. Reverberation time requirements now include the 125 Hz octave band, ensuring that low-frequency sound – which causes fatigue and interferes with speech perception – receives greater attention in design. The standard also includes guidance suggesting that walls be fitted with absorbers corresponding to approximately 8% of the total wall area, with absorption class A according to SS-EN ISO 11654. This is design guidance rather than a binding requirement, but it reflects a clear intent: mid-frequency ceiling absorption alone is no longer considered sufficient.
Enforcement
SS 25268 is a voluntary standard, but it supplements and is referenced by Boverkets Byggregler (BBR), Sweden’s mandatory building regulations. The Basic requirement level is intended to correspond to the statutory minimum; Enhanced applies where a higher acoustic environment is desired or specified.
Practical implications for specification
The guidance on absorption class A wall treatments reflects a design intent that panels and wall systems must actively support. Feltfon panels, when installed with their built-in void, achieve absorption class A (SS-EN ISO 11654) – enabling architects to implement the wall-absorption strategies outlined in SS 25268:2023 and necessary to meet SNR and STI targets in open-plan configurations. Lamellow+ and Lamellow+ Cera, with their fibre-gypsum ribs, provide the structural depth needed to achieve meaningful low-frequency absorption when used as ceiling or wall systems.
Norway – NS 8175:2019
The standard
Norway uses **NS 8175**, published by Standards Norway. The current version is NS 8175:2019, updated from the 2012 edition with stricter requirements, setting clear requirements for maximum noise and reverberation in schools across all room types.
Like Sweden’s standard, NS 8175 uses an A–D classification system, with Class C corresponding to regulatory requirements for new construction and Classes A and B representing higher performance levels.
What it requires
The standard covers schools, kindergartens, offices, hospitals and other building types. For educational spaces, it specifies maximum reverberation times, maximum indoor noise levels, and sound insulation between rooms. The standard has been updated to address open-plan teaching environments specifically, incorporating room acoustic criteria including Speech Transmission Index (STI), distraction distance, and spatial decay rate of speech – recognising that STI alone does not guarantee satisfactory speech conditions and must be balanced with reverberation time and noise level.
Enforcement
TEK17, the Norwegian Building Regulations, does not reference NS 8175 directly by version – the connection runs through the associated guidance document (VEK). In practice, NS 8175:2012 remains the legally cited edition, while NS 8175:2019 is widely applied in current projects as best practice and the preferred basis for design. Architects specifying for Norwegian public schools should clarify with the client and building authority which version underpins the project brief.
Practical implications for specification
Norway has a notably high compliance gap in practice. Many schools do not fulfil current requirements, and acoustic conditions in classrooms in particular are very poor. This creates a significant retrofit opportunity – and a clear case for specifying acoustic ceiling and wall systems from the outset rather than treating acoustics as an afterthought.
🇳🇴Les på norsk / Read in Norwegian
Denmark – BR18 and the absence of a classification scheme
The standard
Denmark’s situation is distinctly different from its Nordic neighbours. While acoustic classification schemes including classrooms exist in Finland, Iceland, Norway and Sweden, no such scheme exists in Denmark. Instead, acoustic requirements for schools are embedded in **BR18**, the Danish Building Regulations, alongside associated guidance.
What it requires
BR18 specifies requirements for reverberation time, sound insulation and indoor noise levels for schools, but without the graduated quality-class structure used elsewhere in the Nordics. The absence of a classification scheme means there is no voluntary “better than minimum” framework to reference in design briefs – compliance is binary.
For classrooms, Danish regulatory requirements align broadly with the Nordic consensus. Reverberation times of 0.5–0.6 seconds for furnished, unoccupied spaces are typically applied through associated guidance and industry practice rather than being stated as explicit figures in BR18 itself; background noise limits of 35–40 dB(A) vary by room type. Denmark implemented stricter reverberation time guidance in 2008, bringing it into closer alignment with neighbouring countries.
Enforcement
BR18 requirements are mandatory. As with most European building codes, they apply to new buildings and conversions, but generally not to renovation projects where the use of the building is unchanged – a significant gap given the age of much of the Danish school estate.
Practical implications for specification
Without a voluntary classification framework, the specification conversation in Denmark tends to centre on minimum compliance rather than design intent. This is an area where architects can lead by referencing international best practice – including the Nordic classification criteria from neighbouring countries – to make the case for enhanced acoustic performance beyond the mandatory floor.
🇩🇰 Læs dette afsnit på dansk / Read this section in Danish
United Kingdom – Building Bulletin 93 (BB93)
The standard
The UK’s educational acoustic standard is **Building Bulletin 93 (BB93)**, formally titled *Acoustic Design of Schools: Performance Standards*, published by the Department for Education (DfE). BB93 is intended to create optimal learning environments by reducing background noise, controlling reverberation, and ensuring speech intelligibility across different types of teaching and learning spaces. It is primarily used by architects, designers, and contractors involved in the construction and refurbishment of schools.
What it requires
BB93 covers four performance areas:
indoor ambient noise levels, reverberation time, sound insulation between spaces, and speech intelligibility in open-plan environments.
Background noise levels:
BB93 sets maximum indoor ambient noise levels that vary by room function. Classrooms should not exceed 35 dB(A); music rooms require a lower limit of 30 dB(A); sports halls and dining areas allow slightly higher levels up to 40 dB(A).
Reverberation time:
In general classrooms, reverberation time should not exceed 0.6 seconds to ensure good speech intelligibility. For larger spaces like sports halls, longer reverberation times are permitted but must still be controlled to maintain clear communication.
Sound insulation:
Between classrooms, a minimum field-measured normalised level difference (DnT,w) of 45 dB is required; music rooms require 55 dB or more given the potential for high sound generation.
Speech intelligibility:
For open-plan teaching and study spaces under defined conditions, a minimum Speech Transmission Index (STI) of 0.6 is required. This applies specifically to open-plan configurations, not o standard enclosed classrooms.
Note on jurisdiction: The Republic of Ireland and the United Kingdom are separate jurisdictions with separate governing documents. Northern Ireland follows BB93 directly as part of the UK framework. Architects working in the Republic must reference the Irish Department of Education’s own guidance, not BB93.
Enforcement
BB93 is Department for Education guidance that satisfies Requirement E4 of the Building Regulations via Approved Document E – making it the standard route to legal compliance for school construction and refurbishment in England and Wales. It is enforced through Building Control and is typically verified through pre-completion acoustic testing.
BREEAM also references BB93 directly: compliance with BB93 is referenced by BREEAM Global as a means of attaining specific credits, verified by site testing in accordance with the Association of Noise Consultants’ Good Practice Guide for Acoustic Testing of Schools, and compliance with a specific BREEAM rating may be a requirement for planning approval.
Practical implications for specification
BB93 is one of the most detailed and prescriptive educational acoustic standards in Europe. Its explicit STI requirement for open-plan spaces is particularly relevant as more schools move toward flexible, activity-based learning layouts. Wall treatments with high Class A absorption are critical to meeting both reverberation and STI targets in these configurations. The Equality Act 2010 adds a further dimension: school client bodies must anticipate the needs of deaf and other disabled children, and when alterations affect acoustics, improvement to promote access for children with special needs must be considered.
Poland – PN-B-02151-4:2015
The standard
Poland’s room acoustic standard for educational buildings is **PN-B-02151-4:2015-06**, which came into force in 2015 as the first Polish standard dealing specifically with room acoustics. The standard sets demands for rooms designed for speech communication, including classrooms, lecture theatres and conference rooms, establishing two criteria to be fulfilled together: maximum reverberation time and minimum Speech Transmission Index.
There are also special requirements for rooms designed for early education, language teaching, or for people with hearing impairment – for which reverberation time must be reduced by 0.1 seconds below the general classroom requirement, and must not exceed 0.6 seconds for hearing-impaired users. Reverberation time must comply with specified thresholds across all octave bands from 250 Hz to 8 kHz.
What it requires
For a standard classroom, the maximum permitted reverberation time under PN-B-02151-4 is 0.6 seconds. Background noise limits under the companion standard PN-B-02151-2:2018 set a maximum of 35 dB for classrooms.
The compliance gap in Poland is stark. Research shows that the average sound level in classrooms during lessons reaches 72 dB – well above the 35 dB legal limit – and many schools have reverberation times of 1.0–1.5 seconds, against a maximum of 0.6 seconds. This reflects a construction culture that has historically prioritised hard finishes – plastered masonry, concrete slabs, hard floors – with no acoustic treatment.
Enforcement
PN-B-02151-4 occupies an unusual position: the provisions of the reverberation standard are recommendations and guidelines rather than rigid rules, though the mandatory building regulations do reference the standard’s requirements for noise levels. In practice, enforcement is uneven, and there is significant pressure from educational bodies and parents’ associations to strengthen compliance.
Practical implications for specification
Poland represents perhaps the most significant opportunity for acoustic improvement in the region. The gap between current conditions and standard requirements is large, awareness is growing, and the business case for retrofit is well documented. Case studies from Warsaw demonstrate that comprehensive acoustic treatment covering classrooms, corridors, canteens, auditoriums and sports halls can bring a whole school building into compliance with PN-B-02151-4 – with measurable improvements in teacher vocal health, student concentration and reported wellbeing.
Comparative overview
The table below summarises the key parameters across all five markets. Values are for standard classrooms in unoccupied, furnished state unless otherwise noted.
| COUNTRY | Governing standard | Max RT (classroom) | Max background noise | Enforcement |
| Sweden | SS 25268:2023 | ≤ 0.5 s (Enhanced) ≤ 0.6 s (Basic) | ≤ 35 dB(A) | Voluntary + BBR reference |
| Norway | NS 8175:2019 | ≤ 0.5 s (Class B) ≤ 0.6 s (Class C) | ≤ 32–35 dB(A) | TEK17 via VEK (2012 ed.) |
| Denmark | BR18 | ≤ 0.6 s (via guidance) | ≤ 35–40 dB(A) | Mandatory (no class scheme) |
| UK (England & Wales) | BB93 (2015) | ≤ 0.6 s | ≤ 35 dB(A) | DfE guidance / Approved Doc E |
| Ireland | SDG-02-05-03 (2020) | ≤ 0.6 s | ≤ 35 dB(A) | Dept. of Education mandatory |
| Poland | PN-B-02151-4:2015 | ≤ 0.6 s | ≤ 35 dB(A) | Recommended (partially mandatory) |
Note: Specific values for music rooms, lecture halls, libraries and sports halls vary by standard. Always consult the current version of the applicable standard for project-specific requirements. Northern Ireland follows BB93 directly under the UK framework.
Common threads and design implications
Despite the national differences, several themes run across all five markets.
The 0.6-second ceiling is near-universal Whether expressed as a mandatory limit, a Class C criterion, or a design target, 0.6 seconds for unoccupied classrooms is the de facto benchmark across Europe. Achieving it reliably in a hard-finished space requires meaningful acoustic treatment – typically a combination of ceiling absorption and wall panels.
Low-frequency absorption is increasingly explicit
Sweden’s 2023 revision specifically added 125 Hz to its reverberation time tables and includes guidance suggesting wall-mounted absorption class A panels covering approximately 8% of wall area. This reflects growing research evidence that low-frequency reverberation causes fatigue and impairs phonological processing – and it points toward products with demonstrable low-frequency performance rather than simply high mid-frequency NRC values. Poland’s PN-B-02151-4 requires compliance across all octave bands from 250 Hz to 8 kHz; Sweden now explicitly extends this down to 125 Hz.
Open-plan spaces require additional specification Both BB93 and NS 8175 address open-plan learning environments explicitly, requiring minimum STI values rather than just reverberation time. This is an area where distributed ceiling systems and integrated acoustic panels provide more benefit than a single dense ceiling treatment.
Retrofit is under-regulated but urgently needed Acoustic regulations are typically valid for new buildings only, including conversions, but not for renovated buildings where use is unchanged. Consequently, large parts of the building stock constructed during periods with missing or weak regulations still suffer from poor acoustic quality. The stakes are concrete: documented retrofit projects show measurable reductions in teacher voice strain and sick leave, improved student concentration and test performance, and reduced noise-related stress for both groups. For architects working on school improvement projects, national standards provide a useful design target even where they are not technically enforceable – and the evidence base makes the case for clients more compelling than ever.
Special educational needs raise the bar All five markets recognise that hearing-impaired students, those with language learning needs, and neurodiverse learners require conditions better than the standard classroom minimum. For these spaces, reverberation targets of 0.5 seconds or below, combined with very low background noise, are the appropriate design goal.
Selecting the right products for compliance
Gustafs products are designed to deliver measurable acoustic performance within architecturally resolved interiors. The selection logic below maps directly to the standard requirements covered in this article.
Feltfon – wall absorption class A for SS 25268, BB93 and NS 8175 compliance.
Feltfon panels, when installed with their built-in void, achieve absorption class A (SS-EN ISO 11654) — enabling the wall-absorption strategies outlined in SS 25268:2023 guidance and necessary to meet SNR and STI targets in open-plan configurations under BB93 and NS 8175. Note: Feltfon installed flat against a wall drops to class D. The void is not optional for class A performance.
Lamellow+ and Lamellow+ Cera – ceiling systems for RT control.
Lamellow+ (fibre-gypsum ribs with wood veneer face) and Lamellow+ Cera (fibre-gypsum ribs with lacquered finish) provide ceiling solutions with good mid-frequency absorption suited to meeting the 0.4–0.6 s reverberation targets required across all five markets. Blayde is specified for ceiling applications only.
Nano Panels – fire-rated specification for educational buildings.
Nano Panels carry B-s1,d0 fire classification – the correct European classification for use in educational buildings. Always verify the applicable national fire standard for each project.
A note on verification and testing
Specifying to the standard is necessary but not sufficient. All five markets discussed here either recommend or require acoustic testing after construction to verify that as-built performance meets design targets. Factors that affect in-situ performance include: actual ceiling and wall surface areas treated, the type and placement of absorption, the presence of hard floor finishes, furniture and occupant load, and flanking transmission through shared structures.
Acoustic modelling at design stage — and pre-completion testing on completion – is the only reliable way to ensure that a school building actually performs as designed. For architects, early engagement of an acoustic consultant and inclusion of post-completion testing in the contract is standard good practice.
Further reading
– Education & Learning Spaces – Acoustic Interiors That Support Learning
– Fire Safety in Wood Interiors