Want to keep your characterful original windows, save money on heating bills and stay warmer in winter? Secondary Glazing could be the Solution!

If that sounds like music to your ears, we’re talking the same language. With those aims in mind, along with our mission to be as environmentally friendly as possible, we created CosyGlazing, our advanced secondary glazing system.

It’s a unique secondary glazing system developed and tested over seven years that is elegant, effective and unobtrusive. We use plexiglass – a modern, lightweight equivalent to glass that’s used in the aeronautical industry – to provide a second layer to your period windows.

It’s effectively double glazing without you having to lose your original windows.

  • CosyGlazing is perfect for sash windows in period homes and listed properties

  • CosyGlazing reduces heat loss from single glazed windows by 70%

  • CosyGlazing fits to every type of window and you can open your windows as usual

  • CosyGlazing is removable and invisible from the outside and so conforms to conservation requirements for Grade 1 and Grade 2 listed buildings

Secondary Glazing Sash Windows

Magnetic Secondary Glazing

So that your secondary glazing can occasionally be removed to be cleaned, it is fixed using high-tech magnetic strips. It’s the same sort of magnetic strip you’ll find holding the windows on The Gherkin.

In order to make the secondary glazing unobtrusive and smart, we supply it in white or in a wooden frame to complement your property. Want us to paint it in a Farrow & Ball tone to match your existing windows? No problem.

If you choose CosyGlazing in addition to our window restoration service, you’ll end up with stunningly restored and painted windows with matching secondary glazing and smart fittings that will find you looking at your windows as much as looking through them.

November 2020

The workmanship was excellent and the windows were draft-proofed as well as glazed

We live in a Grade 2 listed building and so had to be careful that any work done was sympathetic to the building. As the single glazing was cold and expensive on heating costs we decided to have all our windows and outside entry door secondary glazed. Mitchell & Dickinson were excellent throughout the process and we highly recommend them. Initially, due to the COVID lockdown we were not available for the fitment date so M&D were very flexible. Indeed their administration throughout was excellent. Once fitting began the fitting team were courteous, professional and minimised intrusion. The workmanship was excellent and the windows were draft-proofed as well as glazed. The actual glazing panels are unobtrusive and the windows open as intended. Now the work is done the house feels a lot warmer and the heating is not needed to the same degree. We recommend Mitchell & Dickinson.

Stronger than glass

Plexiglass is an excellent solution because it’s both shatterproof and stronger than glass, as well as being seven times more effective as an insulator. It can be scuffed a little more easily than glass, but this does not occur in normal use and can be polished out. It reduces, but is not guaranteed, to eradicate condensation.

Being reversible and invisible from the outside, it is approved for listed buildings.

Secondary Glazing Sash Windows

Our Secondary Glazing is Perfect for sash windows

Our integrated system of secondary glazing for sash windows allows you to slide the sashes open as usual while the CosyGlazing remains in place. As part of the fitting service, our sash window experts restore the window, remove excess paint, release stiff sashes, replace chords, balance weights and fit new beading with a concealed brush strip. Your thermally efficient, draught-free sash windows will then open smoothly.

Secondary Glazing Sash Windows

The solution for period homes and listed properties

The CosyGlazing Secondary Glazing system was designed specifically for period homes and listed properties. We have a huge amount of experience installing secondary glazing to older properties across the South and South West. One major advantage of our system is that it helps improve the thermal properties of your windows without losing their aesthetic appeal.

We have operational teams in Bristol and Bath, across the South and South West, including Cornwall, Devon, Dorset, Somerset, Bristol, Gloucestershire, Monmouthshire, Worcestershire, Warwickshire, the West Midlands, Oxfordshire, Northamptonshire, Buckinghamshire, Wiltshire, Hampshire, Berkshire, Surrey, Sussex and South West London.

Some of our Secondary Glazing

Secondary Glazing FAQs

Secondary glazing allows you to keep your original single glazed windows whilst improving their thermal efficiency. This means your heat loss through your windows can be reduced dramatically which in turn will help to keep you warmer and reduce your energy bills.

At Mitchell & Dickinson we have over 13 years’ experience helping owners of period and listed properties. We know that installing secondary glazing and insulation is the best way to keep your home warm, reduce energy bills and reduce your carbon footprint.

CosyGlazing is Mitchell & Dickinsons award winning and advanced secondary glazing system developed especially for period and list properties. It is an elegant, virtually invisible secondary glazing solution which provides you with warmth and comfort. The fully integrated CosyGlazing solution enables you to still open and close your windows as you always have. It’s completely removable for cleaning and maintenance, and so meets with conservation officers requirements, and there is no additional frame required like traditional forms of secondary glazing.

Yes, there are DIY secondary glazing kits which you can find online, although we cannot vouch for their overall efficiency. If you do not need to ever open your windows then a DIY solution may be adequate, although of course it would not come with a guarantee and lifespans differ from product to product.  Period properties have a tendency to unusually shaped windows that are often not level and as a result a DIY solution can be tricky to install.   Our CosyGlazing system is fully integrated with your windows, your ironmongery and catches are modified to work with the CosyGlazing system to provide maximum efficiency, your windows will be completely reengineered and fully draught proofed by our specialist craftsmen so that they will open and close perfectly as originally designed to. even with the CosyGlazing secondary glazing in place, and you will feel the difference in warmth and comfort of your home immediately.  Employing specialists to fit your secondary glazing ensures a professional installation, guaranteed,  and saves you the stress of doing it yourself.

In most cases, secondary glazing is considered a “permitted development” and doesn’t require planning permission. However, exceptions may apply, especially in conservation areas or for listed buildings. We recommend checking with your local planning authority for specific guidelines.

No, the design of the system is such that is should be virtually invisible from the outside and the inside.

We install a specially modified catch/stay that is able to accommodate the CosyGlazing units on the window and still open and close as usual as part of our award winning system.

When we re-engineer your sliding sash we will add weights to accommodate the weight of the CosyGlazing unit that is attached to the frame of your window using magnetic tapes, and some modifications are made to the meeting rails to enable the casements to pass each other with the CosyGlazing unit fitted to the frame. Some windows are more challenging that others, but bespoke and hand crafted solutions are what we do to the highest standards.

Most period homes have specific hardware such as monkey tail or pig tail catches and stays, and particular locks etc. We usually replace your original hardware with a like for like but modified alternative to meet the crafted CosyGlazing panel, but where we are required to, we can usually modify original hardware where it is essential to the listing of the property. There are of course some situations where this is not possible and your surveyor can advise you accordingly.

There are two sources of condensation.  The first is caused by warm, moist air from inside the room touching the cold glass and condensing.  This is reduced by CosyGlazing but we cannot guarantee it will eradicate it entirely.  The second is caused by external sources of moisture from the building fabric such as from  broken putty allowing rain to leak in under each pane of glass and settle on the lower glazing bars, particularly after rainfall.  Secondary glazing traps this water in the void, which can cause condensation.  Therefore when installing CosyGlazing, it is advisable to keep putty and paintwork in good condition.  This also increases the life of the window.

The cost of secondary glazing varies based on factors such as window size, type, and installation complexity ( ie flat panels won’t allow for you to open your windows without removing the panel first but will be lowest cost)  For a personalized quote, please contact Mitchell & Dickinson for a free consultation and assessment.

The installation time depends on the project’s scope and complexity. Generally, secondary glazing installation is a quicker process than installing new windows. Our team of expert craftsmen at Mitchell & Dickinson strive to minimize disruption and complete installations efficiently.

The effectiveness of secondary glazing depends on various factors, including your original frame materials, and installation quality. Mitchell & Dickinson offers CosyGlazing high-quality bespoke secondary glazing solution tailored to meet specific needs, providing optimal performance. It is made to fit your specific windows using a material called plexiglass which has a guarantee of 30 years.

Both secondary glazing and double glazing offer unique benefits. Secondary glazing is often preferred for heritage properties, where preserving the original window aesthetics is crucial. Mitchell & Dickinson can guide you in choosing the most suitable option based on your preferences and requirements.

Secondary glazing enhances thermal insulation, reducing heat loss by up to 70% and improving energy efficiency  The amount of heat saved depends on factors like the quality of installation and the type of material used. Mitchell & Dickinson’s CosyGlazing secondary glazing solution is designed to optimize energy efficiency and has a U value of 1.7 .

Magnetic secondary glazing is a convenient and effective option for owners of period and listed properties or where the homeowner wishes to retain the original windows. Its performance depends on the quality of materials and installation. Mitchell & Dickinson offers its high-quality bespoke magnetic secondary glazing solution called CosyGlazing, designed to provide optimal thermal and , where required can also provide optimal acoustic benefits.

Secondary glazing offers a range of benefits, including enhanced thermal insulation, noise reduction, and improved security. It is an ideal solution for preserving the character of historic or listed buildings while upgrading their energy efficiency. Contact Mitchell & Dickinson to explore the advantages of CosyGlazing secondary glazing for your property.

CosyGlazing is perfect for sash and casement windows in period homes and listed properties, but can also be fitted to every type of window including metal and stone mullions as well as doors with glazed areas such as French doors.

Yes with the CosyGlazing integrated secondary glazing solution you will be able to open and close your windows just as you always have done. However, if you have metal windows we may need to design a bespoke solution to provide for window opening.

Yes, your CosyGlazing secondary glazing can be removed using suction lifts which are provided by Mitchell & Dickinson for all installations. You are able to then clean your original windows and the CosyGlazing units before popping them back on.

Yes, CosyGlazing can be matched exactly to your current window colour. We can use your original paint colour to create a CosyGlazing unit complete with our Colour Match trim so that the secondary glazing blends in c