Improve Comfort, Reduce Noise & Retain Your Property’s Character
What Is Secondary Glazing?
Secondary glazing involves installing an additional internal window system behind your existing window. The slim secondary frame creates an insulating air gap that helps reduce heat loss, improve sound insulation, and minimise draughts — all while preserving the original exterior appearance of the property.
Improved Thermal Performance
Acoustic Noise Reduction
Heritage-Friendly Solution
Cost-Effective Alternative
Explore Our Secondary Glazing Systems
Aluminium windows combine slim sightlines, outstanding strength, and energy efficiency to create elegant spaces filled with natural light.
Horizontal Sliding Units
Smooth sliding systems ideal for wide windows and easy ventilation access.
Vertical Sliding Units
Perfect for traditional sash windows and heritage properties.
Hinged Secondary Glazing
Side-opening systems allowing easy cleaning and maintenance access.
Fixed Panel Systems
Maximum insulation and soundproofing for non-opening window areas.
Why Choose Secondary Glazing?
Secondary glazing is suitable for most buildings, be it old or new, as it is a subtle addition in keeping with the current window system. It uses a lightweight discreet aluminium system that is fitted in the internal window reveals or face fixed. Updating your windows in this way is a cost effective way to enjoy the following benefits:
Approved by the Heritage society
Approved by the Heritage society for period properties and conservation areas
Improved Energy Efficiency
Improved energy performance due to improved heat retention from the second layer of glass
Reduce noise pollution
Acoustic improvement in reducing noise pollution
Charm & Finishes
Versatile enough to maintain the charm of a property
Safety and Security
Toughened safety glass as standard for additional safety and security
Our Heritage Window Installation Process
Exterior Plas provides bespoke heritage window solutions ideal for period homes, conservation projects, and contemporary architectural designs.
