BREEAM (Building Research Establishment Environmental Assessment Method) is the world's most widely used green building certification system, with over 590,000 certified buildings and 2.3 million registered projects in 89 countries. Within the BREEAM Health and Wellbeing (HEA) category, credit HEA 05 specifically addresses acoustic performance — and it awards up to 3 credits that can make a material difference to overall BREEAM ratings (the difference between "Very Good" and "Excellent" is often fewer than 5 credits).
This guide covers BREEAM HEA 05 requirements in detail for BREEAM New Construction NC 2018 and BREEAM International, providing calculation targets, evidence requirements, and a practical compliance strategy.
BREEAM Scheme Context
BREEAM New Construction 2018 (NC 2018) is the primary UK scheme for new commercial buildings. BREEAM International SD 2016 covers projects outside the UK. The Health and Wellbeing category in NC 2018 carries a maximum weighting of 15%, with HEA 05 accounting for up to 3 credits.
BREEAM rating thresholds (NC 2018):
| Rating | Score |
|---|---|
| Pass | ≥ 30% |
| Good | ≥ 45% |
| Very Good | ≥ 55% |
| Excellent | ≥ 70% |
| Outstanding | ≥ 85% |
The potential value of HEA 05 depends on building size and type, but for a 5,000 m² office building, 3 HEA 05 credits can equate to approximately 1.0–1.5% of the total BREEAM score — often the margin between rating bands.
HEA 05 Assessment Criteria
BREEAM HEA 05 is structured around three criteria, each contributing to the maximum 3 credits. The precise wording varies slightly between scheme versions; the following is based on NC 2018.
Criterion 1 — Internal Ambient Noise Levels (1 Credit)
This criterion requires that background noise levels within key occupied spaces are within limits appropriate to the space use. The assessor checks that:
- Background noise levels meet the design limits in BB93 (educational buildings), BS 8233:2014 (general occupied spaces), or HTM 08-01 (healthcare)
- The acoustic designer has assessed both external noise sources (road, rail, aircraft) and internal mechanical services (HVAC, plant)
- Noise from HVAC systems is controlled to appropriate limits
| Space Type | Standard Referenced | Target (dB LAeq,T) |
|---|---|---|
| Classroom (primary school) | BB93 | ≤ 35 dB |
| Classroom (secondary school) | BB93 | ≤ 35 dB |
| Open-plan office | BS 8233:2014 | ≤ 45 dB |
| Private office | BS 8233:2014 | ≤ 40 dB |
| Library / study space | BS 8233:2014 / BB93 | ≤ 35 dB |
| Hospital ward (daytime) | HTM 08-01 | ≤ 40 dB |
| Meeting room | BS 8233:2014 | ≤ 40 dB |
Evidence required: An acoustic design report from a competent person (typically MIOA or equivalent) demonstrating that background noise criteria have been considered, with predictions or measurements referenced to the appropriate standard.
Criterion 2 — Sound Insulation Between Spaces (1 Credit)
This criterion addresses airborne sound insulation between occupied spaces within the building. The assessment checks that the acoustic separation between adjacencies meets minimum performance requirements.
The concept of critical adjacencies: BREEAM HEA 05 focuses on the highest-risk adjacencies — spaces where privacy, confidentiality, or concentration are paramount, adjacent to spaces with higher noise levels. A private meeting room adjacent to an open-plan office is a critical adjacency; a service corridor adjacent to a plant room is not.
Reference standards for Criterion 2:
- Educational buildings: BB93 sound insulation requirements between classrooms (Dw + Ctr ≥ 40 dB in many cases)
- Offices: BS 8233 guidance values, typically DnT,w ≥ 40 dB for meeting rooms
- Healthcare: HTM 08-01 airborne insulation targets
- Residential within commercial developments: Approved Document E (ADE) if applicable
| Adjacency | Target DnT,w (dB) | Standard |
|---|---|---|
| Classroom to classroom (primary) | ≥ 45 | BB93 |
| Classroom to corridor | ≥ 32 | BB93 |
| Meeting room to open office | ≥ 40 | BS 8233 |
| Doctor's consulting room to waiting area | ≥ 45 | HTM 08-01 |
| Hotel room to hotel room | ≥ 45 | ADE Table 1 |
| Office to toilet/utility | ≥ 43 | BS 8233 |
Evidence required: Acoustic predictions using EN 12354-1 or an equivalent validated method, identifying critical adjacencies, calculating predicted DnT,w for proposed wall/floor construction, and confirming compliance with referenced standard targets.
Criterion 3 — Reverberation Control (1 Credit)
This criterion addresses RT60 within key occupied spaces. Excessive reverberation degrades speech intelligibility, increases noise levels, and reduces wellbeing for building occupants — a recognised causal chain that BREEAM credits buildings for addressing.
Reference standards for Criterion 3:
- Educational buildings: BB93 Sections 1.2–1.4 (RT60 and absorption ratio targets)
- Offices: BS 8233:2014 Table 5 (background noise includes reverberation contribution)
- Healthcare: HTM 08-01 reverberation criteria
- Retail and hospitality: No single referenced standard — assessor discretion applies
| Room Type | Volume Range | RT60 Target (s) | Unoccupied |
|---|---|---|---|
| Primary classroom | ≤ 250 m³ | ≤ 0.6 | Typically ≤ 0.8 |
| Secondary classroom | ≤ 250 m³ | ≤ 0.8 | Typically ≤ 1.0 |
| University lecture theatre | > 250 m³ | ≤ 1.0 | Typically ≤ 1.2 |
| School dining room | > 250 m³ | ≤ 1.0 | — |
| School music room (ensemble) | ≤ 250 m³ | 0.8–1.0 | — |
| School sports hall | All | ≤ 1.5 | — |
| Library / resource room | ≤ 250 m³ | ≤ 0.6 | — |
Evidence required: RT60 calculations using an acoustic modelling tool (Sabine equation, Eyring correction, or geometric acoustics) for each key space type, referenced to the appropriate standard. Measured values from completed analogous projects strengthen the evidence but are not mandatory at design stage.
Common Compliance Challenges
Challenge 1: Hard Ceilings and Exposed Concrete
Contemporary architectural aesthetics favour exposed concrete soffits, polished concrete floors, and minimal soft finishes. These surfaces all have very low absorption coefficients (α < 0.05 at most frequencies), leading to high reverberation times. A 10m × 8m × 3.5m office with exposed concrete ceiling and polished concrete floor will typically achieve RT60 of 1.2–1.8 s — failing BB93 and BS 8233 targets.
Solution: Hanging acoustic baffles or floating ceiling panels above the occupied zone, typically covering 30–50% of ceiling area. At NRC 0.90, baffles covering 40% of the ceiling plane in this room would reduce RT60 to approximately 0.5–0.6 s. AcousPlan's prescription engine can calculate the required coverage percentage for any room geometry.
Challenge 2: Open-Plan Layouts with Glass Partitions
Glass partitions have DnT,w values of approximately 30–36 dB (single glazing) to 40–46 dB (acoustic double glazing). Meeting rooms glazed on one or two sides to an open-plan office frequently fail Criterion 2 targets without enhanced glazing.
Solution: Specify acoustic double glazing (minimum 6-16-6 configuration) and ensure all penetrations (cable trays, ventilation grilles) are acoustically treated. Solid walls from floor to underside of raised floor above (not just to suspended ceiling line) are usually required.
Challenge 3: HVAC Noise Exceeding Criterion 1 Limits
HVAC noise is one of the most frequent Criterion 1 failures. Exposed ductwork with high supply air velocities can produce broadband noise exceeding 40–45 dB(A) in occupied spaces.
Solution: Design supply air velocity ≤ 3.0 m/s at diffusers, provide 1.5–2.0 m of acoustic duct liner downstream of in-duct fans, specify attenuators on supply and return branch connections, and verify the acoustic specification with the M&E engineer early in design (Stage 2 at latest).
Challenge 4: Evidence Quality
BREEAM assessors are required to evaluate evidence quality. Generic statements ("acoustic treatment will be provided") without quantified calculations will fail. The evidence must include:
- Room dimensions and surface areas
- Surface material absorption coefficients with references
- Calculated RT60 values per octave band
- Comparison with the referenced standard's targets
- Identification of the acoustic standard referenced and specific clause numbers
Strategic Approach to Maximising Credits
Get the acoustic engineer involved at RIBA Stage 1 (Preparation and Brief)
The most common reason projects fail HEA 05 credits is late engagement of acoustic consultants — often at Stage 4 (Technical Design) when structural and M&E decisions that affect acoustics are already fixed. Retrofitting acoustic performance into a fixed design is expensive. Early engagement typically costs the same but delivers better outcomes.
Identify critical adjacencies in the Stage 2 report
A Stage 2 acoustic concept report should map all critical adjacencies on the floor plans, flag structural configurations that create flanking risk (steel frame buildings with screed on metal deck are particularly vulnerable), and propose the wall/floor strategy for sound insulation compliance. This report is the foundation of the BREEAM evidence.
Model RT60 for all key space types, not just the highest-risk rooms
BREEAM assessors review evidence for a representative sample of space types. Providing RT60 calculations for classrooms only, in a building with a library, learning resource centres, and a sports hall, creates gaps that assessors may penalise. Calculate and report all space types.
Commission post-completion acoustic testing
While not mandatory for design-stage credits, commissioning acoustic testing after completion — airborne sound insulation per ISO 16283-1, RT60 per ISO 3382-2 — provides definitive evidence and protects against post-occupancy complaint. The cost (£2,000–£6,000 for a commercial building) is small relative to the cost of BREEAM certification itself.
BREEAM International vs NC 2018
BREEAM International SD 2016 uses a similar HEA 05 framework but references ISO standards rather than UK-specific standards (BB93, ADE, BS 8233) where no equivalent national standard applies. For international projects, the acoustic designer should reference ISO 3382-2 (RT60), ISO 16283 (sound insulation measurement), and the applicable national building code for compliance targets.
In markets without detailed national acoustic standards (parts of Southeast Asia, Middle East, Sub-Saharan Africa), BREEAM assessors typically accept BS 8233:2014 as the reference standard for occupied building spaces when no local equivalent exists.
Using AcousPlan for BREEAM HEA 05 Evidence
AcousPlan's compliance module supports direct comparison against BS 8233:2014, BB93, and WELL v2 Feature 74 acoustic performance criteria. The workflow:
- Enter room dimensions, surface materials, and construction details
- Run the RT60 simulation — results across 125–4000 Hz octave bands
- Select the BREEAM-referenced standard (BB93, BS 8233, or custom)
- Generate a compliance report showing pass/fail against each criterion
- Download the PDF report for submission to the BREEAM assessor
Summary
BREEAM HEA 05 awards up to 3 credits for acoustic performance that can be the difference between "Very Good" and "Excellent" certification. The criteria address internal ambient noise levels, sound insulation between spaces, and reverberation control — all quantifiable with acoustic calculations referenced to BB93, BS 8233, or HTM 08-01.
Key success factors: engage acoustic engineers at Stage 1, identify critical adjacencies early, model RT60 for all space types, and produce quantified evidence with referenced standard citations. The credits are achievable with good design practice; they are not achievable by treating acoustics as an afterthought.