Secondary glazing for period homes
Secondary glazing adds a slim internal pane behind your existing windows for £300 to £800 per window. For Teesside's period sashes, listed buildings and conservation areas, it's the approved route to modern warmth and quiet: thermally comparable to double glazing, acoustically better, invisible from the street.
Why period windows are a special case
Teesside's period stock, Saltburn's tall sashes, Norton's Georgian fronts, the West Park villas, the Headland cottages, has windows that are part of the architecture. Replacing them is often restricted, always expensive (£1,500 to £3,000 per window for sympathetic sashes), and usually unnecessary. The original joinery has already lasted a century; it needs help, not replacing.
What secondary glazing is
A slim aluminium-framed pane fitted inside the existing window reveal, operating independently of the original window: sliding panels for sashes, hinged casements, or lift-out panels for fixed panes. From the street, nothing changes. From inside, the wide air gap between the two panes does the work.
Performance, honestly measured
Warmth: thermally comparable to standard double glazing, the 100mm-plus air gap insulates as well as a narrow sealed unit. Noise: genuinely better than double glazing, because the wide gap decouples sound, which is why secondary glazing is the standard fix on busy roads and flight paths. Draughts: the original window still needs draught-proofing (£80 to £200 per window) for the full effect; secondary glazing alone doesn't seal a rattly sash.
Rules and consents
Secondary glazing normally needs no planning consent precisely because it doesn't alter the external appearance, which is why it's the accepted solution for listed buildings and conservation areas. Saltburn and Norton's conservation areas have decades of precedent. The survey confirms the position for your property, but this is well-trodden ground.
What it costs
£300 to £500 for standard windows, £500 to £800 for the tall sashes and bays the period stock is full of, fitted. Against sympathetic sash replacement at £1,500 to £3,000 (where allowed at all), or against doing nothing and heating the street, the maths is usually clear.