8.1 Sound Mapping (S01) & Maximum Noise Levels (S02)
Key Takeaways
- S01 Sound Mapping is the Sound concept's only precondition and requires an annotated floor plan labeling four zone types made available to occupants: Loud, Quiet, Mixed and Circulation zones.
- S01 Part 2 accepts either an acoustic design plan developed by the project team or owner with an implementation timeline, or a detailed report from a professional in acoustics.
- S02 Maximum Noise Levels defines three categories: Category 1 areas for conferencing, learning or speaking, Category 2 enclosed areas for concentration, and Category 3 open areas for concentration, spaces with PA systems and dining areas.
- S02's 3-point tier caps average sound pressure level at 35 dBA in Category 1, 40 dBA in Category 2 and 45 dBA in Category 3, measured over five minutes.
- For dwelling units S02 caps average bedroom background noise at 35 dBA measured over at least 12 hours including 10 pm to 7 am.
8.1 Sound Mapping (S01) & Maximum Noise Levels (S02)
Core Exam Takeaway: Sound has one precondition (S01) and five optimizations (S02–S06), and carries 8 scored exam questions. S01 Sound Mapping creates the four zone labels — Loud, Quiet, Mixed, Circulation — that S02, S03, S05 and S06 all reference. Learn the zones before the numbers. Then memorize S02's 3-point row: 35 / 40 / 45 dBA for Categories 1 / 2 / 3.
Feature S01: Sound Mapping — Precondition
Intent: incorporate the strategic planning required to prevent issues of acoustic disturbance from various sources of noise.
S01 Part 1 — Label Acoustic Zones
- (a) An annotated document is submitted and made available to occupants showing labelled zones throughout the project floor plan or similar schematic:
| Zone | Definition | WELL's examples |
|---|---|---|
| Loud zones | Areas intended for loud equipment or activities | mechanical rooms, kitchens, fitness rooms, social spaces, recreational rooms, music rooms |
| Quiet zones | Areas intended for concentration, wellness, rest, study and/or privacy | restorative spaces, lactation rooms, nap rooms |
| Mixed zones | Areas intended for learning, collaboration and/or presentation | auditoriums, classrooms, breakout spaces |
| Circulation zones | Occupiable areas not intended for regular occupancy | hallways, egress, atria, stairs, lobbies |
- (b) If Loud zones directly border Quiet zones, the project provides a plan for reprogramming or mitigating sound transmission between them.
S01 Part 2 — Provide Acoustic Design Plan
The project provides one of:
- (a) A plan developed by the project team and/or project owner outlining acoustical solutions and a timeline for implementation, focused on managing acoustical comfort, background noise, speech privacy, reverberation time and/or impact noise within the project boundary; or
- (b) A detailed report from a professional in acoustics describing existing conditions, recommended solutions and measurement results, focused on background noise, speech privacy, reverberation time and/or impact noise. These measurements are not required to adhere to the Performance Verification Guidebook requirements for on-site testing.
WELL Core guidance for both parts: whole building, based on any knowledge of anticipated uses.
[!IMPORTANT] S01's zone labels are load-bearing across the whole concept. S03's wall isolation table is keyed to "Loud zones," "Quiet zones" and "Circulation zones." S06's masking thresholds apply to "open areas with Quiet zones" and "enclosed rooms labeled as Quiet zones." A project that labels its zones carelessly inherits the wrong targets everywhere else — which is exactly why sound mapping is the precondition rather than an optimization.
[!TIP] Note that Circulation zones are defined as occupiable areas not intended for regular occupancy — a hallway is occupiable but not regularly occupied, which links this definition straight back to the WELL v2 space-occupancy vocabulary. And note Part 1(b)'s remedy language: "reprogramming or mitigating". Moving the nap room away from the mechanical room is an equally valid answer to a Loud–Quiet adjacency as building a better wall.
[!TIP] Part 2 offers a team-authored plan or an acoustician's report, and the report route explicitly exempts its measurements from Performance Verification Guidebook protocols. That makes S01 Part 2 achievable with an ordinary consultant survey rather than a formal WELL performance test.
Feature S02: Maximum Noise Levels — Optimization (3 pt / WELL Core 1.5 pt)
Intent: achieve desired ambient noise levels such that HVAC, exterior noise intrusion or other noise sources do not impact occupant health and well-being.
The three categories
S02 defines its own category system, which is not identical to S01's zones:
- Category 1 — Areas for conferencing, learning or speaking
- Category 2 — Enclosed areas for concentration
- Category 3 — Open areas for concentration, spaces with PA systems, and areas for dining
S02 Part 1 — Limit Background Noise Levels
For all spaces except dwelling units, commercial kitchen spaces and industrial.
Background noise levels are measured over a period of five minutes and average sound pressure levels do not exceed:
| Sound pressure level | Unit | Category 3 | Category 2 | Category 1 | Points (Core) |
|---|---|---|---|---|---|
| Average SPL (L<sub>eq</sub>) | dBA | 45 | 40 | 35 | 3 (1.5) |
| dBC | 65 | 60 | 55 | ||
| Max SPL (L<sub>Max</sub>) | dBA | 55 | 50 | 45 | |
| dBC | 75 | 70 | 65 | ||
| Average SPL (L<sub>eq</sub>) | dBA | 50 | 45 | 40 | 1 (0.5) |
| dBC | 70 | 65 | 60 | ||
| Max SPL (L<sub>Max</sub>) | dBA | 60 | 55 | 50 | |
| dBC | 80 | 75 | 70 |
For dwelling units: average background noise levels in bedrooms, measured over a minimum 12-hour period which must include the hours of 10 pm to 7 am, do not exceed 35 dBA (L<sub>eq</sub>).
WELL Core guidance: non-leased spaces; consider lobbies, hallways and corridors within non-leased spaces as Category 3; an additional point for also meeting Category 3 levels in leased spaces.
+-----------------------------------------------------------------------------+
| S02: HOW THE TABLE IS STRUCTURED (READ THIS FIRST) |
| |
| THREE AXES, and candidates confuse them constantly: |
| |
| 1. CATEGORY 1 (conferencing/learning/speaking) is the STRICTEST |
| 3 (open concentration / PA / dining) is the LOOSEST |
| |
| 2. METRIC Average SPL (Leq) is 10 dB tighter than Max SPL (LMax) |
| dBC is 20 dB looser than dBA in every single cell |
| |
| 3. TIER The 3-POINT row is 5 dB tighter than the 1-POINT row |
| |
| Anchor to memorize: 3-point, Average, dBA = 35 / 40 / 45 |
| for Category 1 / 2 / 3 |
| Everything else moves from there in clean 5 and 10 dB steps. |
+-----------------------------------------------------------------------------+
[!IMPORTANT] Why dBA and dBC both appear. The A-weighting curve approximates human sensitivity at moderate levels and heavily discounts low frequencies. The C-weighting curve is nearly flat and therefore captures the low-frequency rumble — fan noise, transformer hum, traffic — that A-weighting hides. A room can pass a dBA limit while being genuinely oppressive from mechanical rumble, which is why S02 imposes both, with dBC set 20 dB above the corresponding dBA value in every cell.
[!TIP] The dwelling-unit requirement is measured differently in every respect: a 12-hour minimum window rather than five minutes, mandatorily spanning 10 pm to 7 am, in bedrooms, at 35 dBA L<sub>eq</sub> — the same number as the strictest Category 1 average, but earned over a night rather than a five-minute sample. Sleep is the use case, so the measurement follows the sleeper.
[!WARNING] S02 excludes commercial kitchen spaces and industrial spaces entirely — those environments are inherently loud, and WELL addresses occupant protection there through other means rather than by setting an unachievable ambient limit.
Reading the concept as a system
The five Sound optimizations divide the problem cleanly, and each is worth locating before studying its numbers:
| Feature | Acoustic problem it solves |
|---|---|
| S02 Maximum Noise Levels | Too much ambient noise (HVAC, exterior intrusion) |
| S03 Sound Barriers | Sound passing between enclosed spaces — isolation and speech privacy |
| S04 Reverberation Time | Sound persisting within a space — intelligibility and vocal effort |
| S05 Sound Reducing Surfaces | Build-up of speech and unwanted sound — absorption |
| S06 Minimum Background Sound | Too little ambient noise, which makes distant speech intelligible — masking |
Note the elegant tension between S02 and S06: one caps background sound, the other establishes a floor. A room that is too quiet offers no speech privacy at all, because a conversation two desks away becomes perfectly audible. WELL's answer is a band, not a minimum.
Which four zone types must a project label to satisfy S01 Part 1?
A project's floor plan places a music rehearsal room directly adjacent to a nap room. What does S01 Part 1 require?
Under S02, what average A-weighted sound pressure level earns the 3-point tier in a Category 1 area for conferencing and learning?
How is background noise measured in dwelling unit bedrooms under S02?