Secondary Glazing for Sash Windows

Sash windows have been an integral feature of properties built since the 17th century and were extensively used during the Georgian, Victorian and Edwardian periods.

They look wonderful - but they are notoriously draughty and rattle or vibrate when it is windy - or due to passing traffic, aircraft or train noise - allowing a huge amount of heat to escape and noise to enter.

Many are in Listed Buildings or Conservation Areas and cannot be replaced double glazed, so that secondary sash windows are the product of choice for discreet, highly effective, heat insulation and soundproofing.

Sash windows form a very significant part of a property’s character - that character can be destroyed by modern replacement windows.

Our Legacy Range™ of Sash Secondary Glazing provides the solutions!

Traditional Sash Windows - The Issues

The problems with sash windows tend to be the same whatever the type of property, whether it is a cottage, a Victorian house, or a city centre mansion block flat:

• properties tend to be old so are poorly insulated throughout
• single glazed sash windows are a major source of heat loss
• their construction & age lead them to be draughty and to rattle
• major security risk - they are easy to break into
• noise from outside entering through the sash window is usually a major problem
• full replacements are very costly
• if subject to listed or conservation orders they cannot be replaced double glazed
• joint Freeholds & Leaseholds usually prohibit double glazed replacement windows
• many sash windows suffer badly from condensation
• modern replacements reduce property values

Secondary Double Glazing Sash Windows - The Major Benefits

Sash windows benefit from the installation of secondary glazed sashes more than any other type of window:

• provides a major insulation boost, stops heat loss & cuts energy bills
• tight internal seals stop draughts & rattles
• with Energy Care Glass, a secondary sash is as effective as replacement double glazing Secondary Double Glazing for Sash Windows - Independent Test Results
• dramatically increases security - can be factory fitted with additional security locks and toughened or laminated glass
• excellent noise reduction & soundproofing - see our Case Studies
• secondary sash glazing is a fraction of the cost of replacement sash windows
• accepted for Listed Buildings, Conservation Areas, Joint Freeholds & Leaseholds
• secondary glazing sash windows will control any condensation problems
• retaining the original sash windows protects the value of your property & makes it more attractive to potential buyers should you wish to sell - conversely, removing the original sash windows will significantly reduce the value of your home - as your local estate agent can confirm

The Additional Benefits of Secondary Glazing for Sash Windows

• the primary sash window gains protection from wet rot & black mould infestation
• reduced frequency of the future redecorating & maintenance requirements
• secondary double glazing for sash windows provides a quick, clean installation, no external access or scaffolding is required & there is generally no need to redecorate
• the secondary sash windows are virtually invisible from both the outside & the inside
• secondary double glazing sash windows is the “green” solution, preserving & extending the life of the original sash windows
• secondary glazed sash windows produce far less C0² during the manufacturing process & the added insulation reduces your carbon footprint

The Legacy Range™ of vertically sliding, secondary double glazing for sash windows, has been specifically designed for use with and to discreetly blend with traditional sash windows.

Secondary Sash Glazing - Vertical Sliders

All units are designed with slim sections and smooth operating mechanisms:

• they do not overlap the original sash windows
• you continue to get unobstructed views
• they are easy to open for ventilation when needed
• spiral counter balance systems take the weight and enable finger-tip opening
• additional security options - locks & break resistant glass
• the Legacy Range™ is ideal for conservation projects
• Easy-Clean™ option - fully reversible sashes for easy cleaning of both sides of the secondary sash & the primary window
• robust and simple to maintain
• concealed fixings and traditional finishing trims achieve a discreet, elegant finished job
• available with arched, curved and radius heads
• full colour matching service

Secondary Glazing Sash - Other Suitable Products

Additionally, the following products can also be used for secondary glazing sash windows:

• horizontal sliders - for use over double, “side by side,” Venetian sash windows - or wide sash windows with vertical Georgian glazing bars
• lift out units - for use over small, narrow sash windows, usually cottage style bay window returns, where regular opening for ventilation is not required
• hinged units - in situations where a sash window is next to a door, or in a bay where sash and casement windows are combined

All of our different types of secondary glazing units have:

• fully matching frames
• matched coupling sections - where required over large glazed areas to join units

to ensure that an attractive overall installation can always be achieved

Secondary Double Glazing Sash Windows

All ages, sizes, types & combinations of sash windows can be secondary glazed:

Secondary Glazing for Sash Windows - Independent Test Results

English Heritage - Secondary Glazing Sash Windows

During 2009, English Heritage carried out thermal insulation tests on a sash window from the 1880’s.

As part of their tests, they fitted good quality secondary sash glazing - the results were dramatic:

• The secondary sash windows achieved a U Value of 1.8 W/m²K and a reduction in heat loss of 58%

The full report and test results can be seen here (See pages 5 to 7)

Historic Scotland - Secondary Glazing Sash Windows

In 2008, the Centre for Research on Indoor Climate & Health at Glasgow Caledonian University, carried out similar thermal insulation testing and gained even better results:

• The secondary sash windows achieved a U Value of 1.7 W/m²K and a reduction in heat loss of 63%

To see the full report please click here

Further information:

• How to get Prices
• All products are Comprehensively Guaranteed
• Secondary Glazing for Listed Buildings & Conservation Areas