8.6 Quality Views and Acoustic Performance
Key Takeaways
- Quality Views (1 point) requires a direct line of sight to the outdoors via vision glazing for 75% of all regularly occupied floor area.
- Quality Views also requires that views include at least 2 of 4 view-content qualities: views of nature/flora/fauna/sky, views with movement, views at least 25 ft from the glazing in 90% of regularly occupied area, or unobstructed views at multiple lines of sight from a single workstation.
- Acoustic Performance (1 point) requires HVAC background noise levels of 35-40 dBA (NC 30-40) depending on space type, sound transmission class (STC) ratings for composite walls/floor-ceiling assemblies based on adjacency type, and controlled reverberation times.
- Reverberation time targets follow ANSI/ASA S12.60-2010 Part 1 for classrooms (≤0.6 s for rooms ≤10,000 ft³; ≤0.7 s for 10,000-20,000 ft³) and NIBS Guideline 3 for other space types.
- Acoustic Performance is required for Schools and Healthcare BD+C as a prerequisite, but is an optional credit in the other BD+C rating systems (NC, CS, Retail, Data Centers, Warehouses, Hospitality).
EQ Credit: Quality Views (1 Point)
Intent: Give building occupants a connection to the outdoor environment by providing quality views.
Geometry Requirement
Provide a direct line of sight to the outdoors via vision glazing for 75% of all regularly occupied floor area. Vision glazing means transparent glazing between 30 and 90 inches above the finished floor (typical seated and standing eye height). Spandrel, frosted, and obscured glass do not count toward vision glazing.
View Quality Requirement
In addition to the 75% line-of-sight test, the views available from those areas must include at least 2 of the following 4 view-content qualities:
| # | View Quality | Description |
|---|---|---|
| 1 | Nature | Flora, fauna, or sky visible from the regularly occupied space |
| 2 | Movement | Views with movement within 90 ft - pedestrians, vehicles, water |
| 3 | Distance | Views at least 25 ft from the inside of the glazing in 90% of the regularly occupied area |
| 4 | Multiple lines of sight | Unobstructed views in multiple directions from a single workstation (≥90 degrees apart) |
For projects with multiple buildings or floors, the calculation is by total regularly occupied area, not by floor.
Common Exam Pitfalls
- The 75% threshold applies to floor area, not to the number of workstations.
- Conference rooms, lobbies, and break rooms are not regularly occupied if occupants spend less than one hour per person per day there - they're excluded from the calculation.
- Storefronts, classrooms, and patient bedrooms count if they are regularly occupied.
EQ Credit: Acoustic Performance (1 Point)
Intent: Provide workspaces and classrooms that promote occupants' well-being, productivity, and communication through effective acoustic design.
Acoustic Performance has three requirement domains. The project must satisfy all that apply: HVAC background noise, sound transmission, and reverberation time. (Sound reinforcement is required for schools but not credit-relevant for most other BD+C rating systems.)
Domain 1 - HVAC Background Noise
Design HVAC systems to meet maximum background noise levels in occupied spaces:
| Space Type | Maximum NC | Maximum dBA |
|---|---|---|
| Classrooms, conference rooms | NC 30 | 35 dBA |
| Private offices | NC 30-35 | 35-40 dBA |
| Open offices | NC 35-40 | 40-45 dBA |
| Patient rooms | NC 30 | 35 dBA |
| Lobbies, corridors | NC 40 | 45 dBA |
Designers use vibration isolators, lined ductwork, lower face velocities, and silencers to hit these targets.
Domain 2 - Sound Transmission
Walls, floor-ceiling assemblies, and doors between adjacent spaces must meet a minimum composite Sound Transmission Class (STC) rating based on adjacency:
| Adjacent Spaces | Minimum STC |
|---|---|
| Office to office, private | 45 |
| Standard classroom to standard classroom | 50 |
| Classroom to a music or activity room | 60 |
| Patient room to patient room | 45 |
| Mechanical equipment room to occupied space | 60 |
Composite STC accounts for doors and windows in the wall assembly, not just the bulk wall material.
Domain 3 - Reverberation Time (T60)
Meet the maximum reverberation times from ANSI/ASA Standard S12.60-2010, Part 1 (for classrooms) and NIBS Guideline 3 (for other rooms).
| Space Type | Volume | Max T60 |
|---|---|---|
| Core learning space (classroom) | ≤10,000 ft³ | 0.6 s |
| Core learning space (classroom) | 10,000-20,000 ft³ | 0.7 s |
| Private office | n/a | 0.6 s |
| Open office | n/a | 0.8 s |
| Conference room | ≤20,000 ft³ | 0.6 s |
| Patient room | n/a | 0.6 s |
Control reverberation with acoustic ceiling tiles, wall panels, carpet, and curtains. Hard, parallel surfaces are the typical culprits when measured T60 exceeds the target.
Schools and Healthcare Difference
In the Schools and Healthcare BD+C rating systems, an acoustic performance prerequisite with stricter requirements applies. Acoustic Performance as a 1-point credit is found in the other BD+C rating systems (NC, CS, Retail, Data Centers, Warehouses, Hospitality), where it builds on those prerequisites by extending the same logic across more spaces.
A 100,000 sf open office plan provides direct line of sight to outdoor vision glazing for 80% of the regularly occupied floor area. Views from those areas include flora/fauna visible through the glazing and pedestrian movement within 90 ft on the street below. Does the project earn the Quality Views credit?
A classroom in a public elementary school has a volume of 8,000 ft³. According to ANSI/ASA S12.60-2010 Part 1, what is the maximum allowed reverberation time?