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Description
Supplementary glazing attached to window frame on the inside of single glazed windows.
Unit cost of installation
~£1200 depending on system used.
Bulk cost of installation
Data not available.
Indicative cost and carbon saving
| £/yr saving
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kgC/yr saving
|
| from
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to
|
from
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to
|
|
|
| 25
|
70
|
85
|
200
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Maintenance
None normally required.
Lifetime
Commercial systems should last the life of the original frame to which it is fitted
Technical suitability
Need to consider ventilation issues when installing secondary glazing. Secondary glazing should be draught stripped, but the original frame should not (to prevent condensation between the two). Other issues raised under draught stripping are also relevant. Secondary glazing can restrict safe egress through a window in an emergency, so consideration should be given to the choice of an appropriate system or possibly leaving one window untreated. Need to ensure that rapid ventilation can still be achieved (i.e. that the secondary glazing does not prevent easy opening of windows).
Non-technical constraints
Secondary glazing may not be wanted in summer particularly if it restricts the opening of windows, so occupants may try and take it down. This can lead to a storage problem, and potential danger of breaking the panes leading to personal injury.
Potential concerns with fuel poor
No specific issues.
Ancillary benefits
Secondary glazing can improve sound insulation if air gap between it and the original window is 150mm or more ; draught stripping the secondary glazing will also improve sound insulation. Condensation on windows can be reduced.
Trigger points for work
Small refurbishment works and decoration.
Performance Limitations
No specific limitations
Technical Guidance Available
» CE184 - Practical refurbishment of solid-walled houses
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