Acoustic & security options
Noise and security are not “add-on glass” in isolation. They are complete openings: frame, seals, support, ironmongery, and the interaction with flanking masonry and mullion joints. This page is the long-form version of the short product brief—use the figures from the issued METABUILD product schedule to align numeric targets where your test evidence differs.
We design upgrades against site noise maps (Lden, Lnight), the architect’s performance specification, and any planning condition that names dBA targets at the façade. On security, the route is tested and declared resistance classes, not ad hoc “burglar bars.”
Acoustics: principles
Sound reduction improves with mass (heavier glass, laminated plies, wider cavities) and decoupling (asymmetrical IGU, different thicknesses, wider spacer to reduce coincidences, resilient perimeter joints). A higher Rw alone does not always fix low-frequencies from rail—spectrum adaptation (C, Ctr) can be the governing column in your specification.
Typical IGU levers (examples only)
- Asymmetrical 6–8 mm / 8–6 mm build-ups; wider cavity 16–20 mm with argon and warm-edge spacers.
- Acoustic laminates: polyvinyl butyral (PVB) or special acoustic interlayers; trade thicker stack against daylight and IGU weight.
- Triple units: middle pane as mass layer; careful with cavity widths to keep Ug acceptable.
- Trickle vents: selected models maintain acoustic class or use baffles—never assume a vent is neutral.
On-site performance includes flanking via reveals, piers, and the junction with spandrel. We call out backer rod, mastic type, and isolating pads; site tests (speaker or traffic) are scheduled where the contract requires proof.
Security: what “RC” and “PAS” require
Resistance classes and PAS 24 / Secured by Design (where used) are based on a full assembly tested as one item: frame, reinforcement, beading, locks, cams, glass type, and edge cover. You cannot sub in a “stronger” glass without re-checking the test route; sometimes a thicker IGU alters the closing force or the cam engagement.
Hardware packages
- Multi-point espag on vertical edges with mushroom heads into steel keeps; shootbolts to head/ sill where applicable.
- Laminated inboard to delay breach and to retain shards if broken.
- Reinforced outer frame fixings, anti-lift for sliding, and hinge side strap screws to manufacturer torque.
- Concealed hinges only where the system has a matching declaration; otherwise visible, tested variants.
Glass selection matrix (conceptual, not a warranty)
The matrix is a decision aid. Field STC, Rw, and security class are taken from the test reports you adopt per project.
| Light road / internal partition | Double IGU, standard lamination; focus on flanking, not over-spec glass. |
|---|---|
| Primary road frontage | Thicker panes, acoustic lam, wider cavity, premium spacer; add secondary treatments if the site test fails by 1–2 dB. |
| Rail / low-frequency | Heavier make-ups, mass–spring–mass tuning; sometimes triple; specialist interlayers. |
| High security | Tested class with the exact IGU, hardware, and frame depth; no substitutions without written sign-off. |
| Map each row in your performance matrix to a tested reference code we will repeat on the order documents. | |
Documentation in the package
- Acoustic report assumptions (source levels, target indoor, margin).
- Security test references (standard, class, year, and glass code).
- Factory QC checks for IGU and hardware batch traceability.
- Site pre-completion checklist: seal continuity, lock adjustment, and vent closure position.
Maintenance and liability
Laminated outer panes in coastal UV may need edge protection per the supplier. Security hardware is sensitive to mis-alignment; maintenance contracts should include annual torque checks where the manufacturer requires them. Acoustic performance can degrade if user-installed blinds pierce the internal line with fixings into a metal mullion—our details include approved blind support zones.
Book an acoustic or security review
Send the planning noise condition, a marked elevation, and the required classes—we will return a make-up table.
Contact METABUILD