Secondary Glazing vs Acoustic Window Inserts
Magnetic and press-fit acoustic inserts are half the price and one-quarter the performance — a fair trade for renters, a bad trade for owners.
Where inserts work
Rented flats where you can't drill the reveal, short-term acoustic tests, and small light-well openings where a full install is overkill.
Where inserts fail
Long-term acoustic performance drops as the magnetic seal loses its grip; thermal performance is minimal because the seal is imperfect; the panel warps and yellows within 3–5 years.
The acoustic gap
A properly installed secondary glazing system delivers 40–47 dB Rw. Magnetic inserts typically top out at 25–28 dB — the difference between muffling traffic and eliminating it.
What we recommend
If you own the property, pay once and install properly. If you're renting, a magnetic insert is the right compromise — but ask your landlord about a secondary glazing spec first, because it often qualifies for tenant-improvement funding.
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South Yorkshire's specialists in secondary glazing — survey, measure, manufacture and install.