STC 28 to STC 50 glass partition acoustic performance compared for hospitals, airports, IT parks, boardrooms and institutional buildings. NBC 2016 requirements, glazing configurations and specification guide for EPC procurement teams across India.
Get a QuoteSound Transmission Class (STC) is the single-number rating that quantifies how much airborne sound a partition assembly attenuates. For glass partition specification in commercial buildings, STC is the primary acoustic performance metric used by acoustic consultants, NBC 2016 compliance documentation, and institutional facility standards.
A higher STC number means better sound isolation. The practical difference between STC ratings is significant — each 10-point increase represents a perceived halving of sound transmission to the human ear. For EPC procurement teams, specifying the correct STC rating from the outset avoids costly post-installation acoustic remediation, which is common on Indian commercial projects where acoustic requirements are often underspecified at tender stage.
| STC Rating | Audibility | Typical Application | Glazing Configuration |
|---|---|---|---|
| STC 28–32 | Loud speech clearly audible | Open plan dividers, reception screens | Single 8–10mm toughened glass |
| STC 33–37 | Loud speech audible, not intelligible | Standard office partitions, meeting rooms | Single 12mm or laminated 6+6mm |
| STC 38–42 | Normal speech inaudible | Boardrooms, HR offices, hospital consulting rooms | DGU 6+12+6mm or laminated DGU |
| STC 43–47 | Very loud sounds faintly audible | Recording studios, confidential offices, ICU | Asymmetric DGU 6+16+8mm laminated |
| STC 48–50 | Near-complete sound isolation | Airport lounges, government boardrooms, IIT labs | Triple glazed or specialist acoustic laminate |
NBC 2016 Part 8 (Building Services) sets minimum airborne sound insulation requirements for partition walls in commercial buildings. The code uses Rw (weighted sound reduction index) rather than STC, but the two values are approximately equal for practical specification purposes (STC ≈ Rw ± 1–2 points).
Key NBC 2016 acoustic requirements for glass partitions in commercial buildings:
These requirements apply to the complete partition assembly — not just the glass. Frame sealing, perimeter details, and flanking sound paths via floor and ceiling are critical to achieving the rated performance in-situ. A correctly specified STC 40 glass partition can perform at STC 30–32 in practice if frame sealing is poor.
8mm, 10mm or 12mm single toughened glass. Lowest cost, maximum transparency, minimum acoustic performance. Suitable for open-plan office dividers and reception screens where speech privacy is not required. Typical for frameless partition systems in corporate lobbies.
6+6mm or 8+8mm laminated glass with PVB interlayer. The PVB layer damps resonance frequencies that cause coincidence dip in single glass — achieving STC 5–7 points higher than equivalent single glass thickness. Cost-effective mid-range acoustic performance for boardrooms and HR offices.
6+12+6mm or 6+16+6mm DGU. The air gap significantly attenuates mid-frequency sound. For maximum performance, use asymmetric pane thicknesses (e.g. 6+12+8mm) to avoid coincidence dip at the same frequency in both panes. Standard specification for acoustic glass partition systems.
Laminated glass on one or both faces of a DGU. 6lam+16+8lam achieves STC 48–50 in ideal conditions. Used for government boardrooms, IIT research facilities, airport premium lounges and hospital ICUs. Requires robust aluminium frame with acoustic seals throughout.
The frame system accounts for 20–30% of the total acoustic performance of a glass partition. For STC 38+ specifications, the following frame requirements are critical:
For framed glass partition systems, the aluminium frame provides the structural base for all perimeter sealing. For frameless systems, acoustic performance above STC 38 is difficult to achieve without compromising the minimal-frame aesthetic.
| Application | Minimum STC | Recommended Glazing | Frame System |
|---|---|---|---|
| Open plan office dividers | STC 28–32 | 10mm single toughened | Frameless or framed |
| Standard meeting rooms | STC 35–38 | 6+6mm laminated | Framed aluminium |
| Boardrooms / HR offices | STC 40–42 | 6+12+6mm DGU | Framed with acoustic seals |
| Hospital consulting rooms | STC 42–45 | 6+16+6mm DGU or laminated | Heavy framed, full-height to slab |
| Airport premium lounges | STC 45–48 | Asymmetric laminated DGU | Heavy framed, acoustic door |
| Hospital ICU / Govt boardrooms | STC 48–50 | Laminated DGU both faces | Specialist acoustic system |
NBC 2016 Part 8 requires minimum Rw 45 dB (approximately STC 43–45) for hospital patient rooms and consulting rooms. For ICUs and operation theatres, Rw 50 dB (STC 48–50) is required. These ratings must be achieved by the complete partition assembly including frame sealing — not just the glass specification.
STC (Sound Transmission Class) is the American standard (ASTM E413). Rw (weighted sound reduction index) is the European/ISO standard (ISO 717-1). Both measure airborne sound insulation but use slightly different frequency weighting curves. For Indian commercial project specification, the values are approximately equal (STC ≈ Rw ± 1–2 points). NBC 2016 uses Rw; most Indian glass suppliers quote STC. Both can be used interchangeably for specification purposes at the tolerances relevant to commercial construction.
Frameless glass partitions can achieve STC 38–40 with laminated DGU and careful perimeter sealing. Above STC 40, the minimal fixing detail of frameless systems makes consistent perimeter sealing difficult to achieve and verify. For STC 42 and above, framed aluminium partition systems with continuous EPDM acoustic seals are the reliable specification choice.
The most common reasons for acoustic underperformance in installed glass partitions are: partition terminating at a suspended ceiling instead of the structural slab (loses 8–12 STC points); gaps in perimeter EPDM seals; door seals that are worn or incorrectly fitted; and flanking paths through the floor or ceiling void. The glass specification is only one element of the total acoustic system.
Full range of acoustic glass partition systems from standard DGU to specialist laminated configurations. Performance documentation supplied.
All acoustic partition systems comply with NBC 2016 Part 8 sound insulation requirements. Compliance documentation available for project submissions.
Partition systems designed for full-height installation to structural slab — the correct installation detail for STC 40+ performance.
Acoustic glass partition supply to airports, hospitals, IIT campuses, government buildings and institutional projects across India.
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