What is the NRC requirement for open office walls?

• A. 0.9 on all walls
• B. 0.7 on 50% walls
• C. 0.8 on 25% walls
• D. 0.8 on 50% walls

Answer: (C)

In acoustics, the NRC (noise reduction coefficient) measures how well a surface absorbs sound, with higher values meaning more absorption and less reverberation. For open offices, WELL sets a practical target to balance performance and cost: have an NRC of 0.8 on 25% of the walls. This level of absorption helps reduce reflections and improve speech privacy without requiring every wall to be covered. Materials or assemblies that achieve NRC around 0.8—such as fabric-wrapped panels, perforated wall panels with an absorbent backing, or similar acoustical finishes—can be used on the selected wall areas. The other options would either impose more stringent requirements (0.9 on all walls) or use different combinations of coverage and absorption that don’t align with the standard.