International acoustic standards for public libraries are clear. ANSI S12.60 mandates RT60 ≤ 0.6 seconds and background noise ≤ 35 dBA for reading and study spaces, while DIN 18041 classifies library lending areas as Group B4 (noise reduction and interior comfort) and sets the absorption area-to-volume ratio (A/V) as the design criterion.
However, in Korea, both the Library Act and the Ministry of Culture, Sports and Tourism manual remain at the level of qualitative recommendations, leaving no quantitative criteria that can be applied in practice.
Acoustics is invisible, yet it is a critical design element that governs users' concentration and cognitive development.
The Role of the Library — Five Spaces in One Building
Public libraries carry out their original purpose of collecting, organizing, and preserving materials while simultaneously serving as community information hubs, lifelong learning venues, and cultural and arts event spaces.
The result is that five spaces with very different acoustic requirements coexist within a single building: the reading room (individual concentration), the stacks area (shelf browsing and circulation), meeting and discussion rooms (group conversation), exhibition spaces (open space), and performance spaces (auditorium or studio theater).
(Kim Seon-ae, "A Study on Deriving Standards for Space Management in Public Libraries," Journal of the Korean Biblia Society, Vol. 19, No. 2, 2008)
Why Acoustic Performance Standards Are Needed
Spaces with different purposes require different acoustic targets. The reading room and stacks need office-level acoustics; meeting and discussion spaces need conference-room-level standards; exhibition spaces need open-space criteria; and performance spaces need concert-hall criteria — each must meet those targets to serve its intended purpose. Acoustics is invisible, but it has measurable effects on productivity and cognition.
International Quantitative Standards vs. Domestic Qualitative Recommendations
ANSI/ASA S12.60 (USA) includes libraries as "core learning spaces" and mandates RT60 ≤ 0.6 seconds and background noise ≤ 35 dBA.
DIN 18041 (Germany) classifies library lending areas as Group B4 and recommends a minimum absorption area-to-volume ratio (A/V) across the 250 Hz–2 kHz band. BB93 (UK school acoustics standard) also specifies library background noise of 40–45 dBA.
In contrast, the 2022 Public Library Construction and Operation Manual published by Korea's Ministry of Culture, Sports and Tourism relies mainly on qualitative language such as "the children's resource area shall be arranged to avoid disturbance from noise" — providing no actionable numeric criteria.
Recommended Acoustic Standards by Space Type
Recommended RT60, NC, and background noise per zone. Compiled from ANSI S12.60, DIN 18041, BB93, and international acoustic consulting cases. ◆ = strictest target.
| 기준 | 열람실 · Reading | 장서 · Stack | 회의/토론 · Meeting | 전시 · Exhibition | 공연 · Performance |
|---|---|---|---|---|---|
| RT60 (s) | 0.4 - 0.6 ◆ | 0.6 - 0.8 | 0.5 - 0.7 | 0.8 - 1.2 | 0.9 - 1.5 |
| NC (Noise Criteria) | NC 30 ◆ | NC 35 | NC 30 - 35 | NC 35 - 40 | NC 25 - 30 |
| Background (dBA) | 35 - 40 | 40 - 45 | 35 - 40 | 40 - 50 | 30 - 35 ◆ |
| Reference standard | ANSI S12.60 / BB93 | DIN 18041 B4 | ANSI / ISO 11690-1 | IFLA / ISO 11690-1 | ISO 3382-1 (performance) |
Absorption Strategy Matrix by Space Type
Reading room (individual focus)
Target RT60 0.4-0.6s, NC 30
Stack area
Block flutter echo
Meeting / discussion
Speech clarity + isolation
Exhibition (open)
Large-volume reverb control
Performance hall
Precise RT60 0.9-1.5s by use
High ceiling (5 m+)
Volume 1000 m³+ excess reverb
Where Domestic Guidelines Currently Stand
The 2022 Public Library Construction and Operation Manual from the Ministry of Culture, Sports and Tourism is primarily qualitative regarding acoustics, using language such as "the children's resource area shall be arranged to avoid disturbance from noise." The Enforcement Rules of the Library Act also focus on floor area and collection size rather than acoustic numeric standards. This structural gap is the primary reason acoustics is routinely overlooked at the design and construction stages.
As Korea takes its place among advanced nations, acoustics — invisible though it is — must be recognized as a critical design element with measurable effects on users' concentration, productivity, and well-being, and included as a mandatory item for review at the design stage.
The measurement infrastructure is already in place: KS F 2805 (reverberation room absorption performance) and ISO 3382-2 (ordinary rooms) provide actionable frameworks.
Information on acoustic materials is available through the melamine foam material guide and the NRC (Noise Reduction Coefficient) comprehensive guide; for project-specific simulation and material recommendations for library projects, please visit the Tornex consulting inquiry page.
Some content herein draws from a presentation by Dr. Jeong Jeong-ho of the Korea Fire Institute.
4 Questions to Ask When Selecting an Interior Contractor
In the absence of domestic guidelines, asking the following 4 questions during the contractor selection stage alone can make a significant difference in the acoustic quality of the finished library. Difficulty increases from question 1 to 4, but even applying question 1 alone yields far better results than taking no acoustic measures at all. Acoustic treatment does not mean a dramatic budget increase.
1. Does the contractor identify and design spaces from an acoustic perspective?
Simply classifying the interior into "loud spaces / quiet spaces / mixed spaces" before design begins improves outcomes. Acoustic zoning naturally leads to sound isolation and absorption review for each space.
2. Is the contractor aware of the target RT60 for each room?
Verify that the contractor is familiar with the space-type benchmark table in this article (reading room: 0.4–0.6 s, meeting room: 0.5–0.7 s, etc.). Design that accounts for target reverberation time produces meaningfully different results from design that does not.
3. What background noise level (dBA) is the contractor targeting?
Verify that the contractor has quantitative targets such as NC 30 (reading rooms and performance spaces) or NC 35 (meeting rooms and general offices). Ask whether there is a specific plan to control intrusive noise — floor impact noise, speech privacy, and HVAC noise.
4. Can the contractor demonstrate goal achievement through post-installation measurement?
Verify that the contractor can measure and report maximum noise level, reverberation time, background noise, and sound isolation performance based on KS F 2805 or ISO 3382-2. Measurability is the primary indicator of accountability.