Double & Triple Glazed Casement Windows

uPVC Casement windows open outwards and can be hinged from the top or side. Depending on the size of your windows they can be divided up using side openers, top openers and fixed panes with hundreds of different combinations available to suit your house design, choice and Building Regulations. All our casement windows are Energy Rated A or above through the BFRC.

A Rated Windows Using Planitherm Total + Insulated Glass (As Seen on TV)

Over a quarter of all domestic heat loss escapes through windows and doors and with spiralling energy bills this can add up to a lot of wasted money. The single most important factor, relating to the energy efficiency of a window, is the glass.

By combining SGG PLANITHERM TOTAL+ with other specialist glass products available, a multitude of high performance, multi-functional double glazing solutions can be achieved.

Solar Control Glazing

The SGG COOL-LITE family presents an extensive range of solar control solutions, designed to reduce solar heat gain, thereby reducing reliance on ventilation and air conditioning systems.

Low-maintenance Glazing

SGG BIOCLEAN can be combined with SGG PLANITHERM TOTAL+ to add effective self-cleaning properties to a double glazed unit. This product combination offers a significantly more neutral and less reflective solution compared to equivalent products currently available on the market.

Acoustic Glazing

SGG STADIP SILENCE is an acoustic PVB laminated glass, which noticeably reduces noise while also offering the same safety and security characteristics as laminated glass.

Increasing Solar Gain to Increase Energy Rating

Window Energy Ratings Combining SGG PLANITHERM TOTAL+ with SGG DIAMANT low-iron glass in the outer pane can improve the energy index of a given window by further increasing solar gain.

‘A+’ Triple Glazing

The inner panes are constructed using two panes of Planitherm Total+and the outer is the glass of your choice, tinted, self-cleaning, clear etc. The gap between the panes is filled with 90% argon gas for increased insulation (krypton gas also available). We always toughen the centre pane, to reduce the risk of stress fractures, which is common in triple glazing if units are not manufactured to this specification. Triple Glazing is an excellent option for conservatories because the extra pane of glass reduces solar gain and increases the thermal efficiency, which will keep your room cooler when exposed to the summer sun. Double glazing will increase the thermal gain, warming your home but the thermal insulation will be lower. For this reason, one option nearly outweighs the other. All new replacement windows, into residential dwellings, must have a BFRC energy rating (most people will be familiar with this on white goods) of ‘C’ or better (with the exception of listed buildings). Both our triple and double glazed Casement windows can meet the newly introduced ‘A+’ rating for the most energy efficient windows. So which option do you choose? Here are a few facts to help you decide;

‘A+’ double glazing is more cost effective than ‘A+’ triple glazing. It is doubtful that the extra cost of triple glazing (compared to ‘A+’ double glazing) will be re-cooperated.

If your windows are in the shade then ‘A+’ triple glazing will be of greater benefit by retaining more warmth within the dwelling.

If your windows are on a sunny aspect, then the benefit of ‘A+’ double glazing will increase by helping to warm your dwelling.

To reduce solar gain, triple glazing is a more effective option.

The clarity of double glazing is clearer than triple glazing.

Dew is more likely to form on the outside of triple glazing; This will soon disappear as the outer pane warms.

Condensation, on the inside, is less likely to form on ‘A+’ triple glazing.

It is definitely, in Test Valley windows interest to install triple glazing, due to the increased order value. However, this is not how we have gained our reputation. Our representative will discuss the different options and offer sound advice to help you make an informed decision.

Super Spacer

To enhance the thermal efficiency and life of our windows we fit our double glazed units with low conductivity Super Spacer. This replaces the traditional metal bar and helps prevent or eliminate condensation round the edge of the sealed unit.The spacer is manufactured from a high-quality silicon that increases the seal’s durability, is resistant to ozone, UV light and oxidation. All this increases the life expectancy of the sealed unit.A high desiccant content absorbs any moisture that is in the environment during manufacture increasing the clarity of the unit.


Our PVCu Windows are manufactured using the most up-to-date modern materials. Back this up with our security guarantee and our 10-year insurance backed product guarantee, you can have confidence in your decision when choosing “Test Valley Windows”.

Fifteen wood grained finishes hundreds of colours

With a vast range of designs and finishes the choice is endless. In addition to white PVCu, you can choose from 15 different grained finishes or select your RAL colour from hundreds of options.

Thermal Reinforcing

We all know how important it is to fit energy efficient windows, not only can they save your family money, they can also reduce your impact on the environment too.

But is there a way to make your energy rated windows work even harder for you? There is with Test Valley Windows!
As a company committed to environmental issues, we are constantly striving to improve the products we offer, which is why all our windows are now supplied with recycled PVCu thermal reinforcement.

What are thermal reinforcements?
Windows are traditionally manufactured with steel or aluminium reinforcement which provides strength and support. However, steel is not an insulating material, which means valuable heat can be lost simply through the material used to reinforce frames. PVCu thermal reinforcements are not only as strong as steel; they are the simplest way to boost the thermal efficiency of your windows. The unique multi chambered design creates a barrier against airflow travelling through the window, which minimises the heat which can be lost through your window frames.

Superior Weather Seals

Our triple weather seal is said to be one of the World’s best door and window seals. It out performs double seals on air tightness and acoustic and thermal performance. The inner and outer weather seal is extruded to the PVCu profile meaning that it will not shrink and therefore will retain the highest weather performance for years to come.

The seals low sightlines leave your doors and windows with a sharp finish, clean lines and no unsightly black gasket protruding from the frame.

Design Options

All our windows are made to measure to ensure that your windows are designed to your requirements. Our representative will spend time listening to create a design and free estimate tailored to you, your property and your budget.

Leaded Glass

10 standard leaded designs are available. We can also match your existing lead design.
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Stained Glass

Choose from our extensive range or design your own stained window to add individual style.
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Obscure Glass

We offer the Pilkington textured glass range when privacy glazing is required.
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Locking handle options with a push to release safety lock and crank for easy use of night vent facility.

A Rated Windows

All our casement windows are A or A+ rated and can be double or triple glazed.

Georgian Bar

Authentic astrical Georgian or our easy clean bar, fitted between the glazing, is available in various sizes.
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Security Glass

Test Valley windows strive to offer all our customers the ultimate choice and service. With this in mind, we offer our unique security guarantee. To qualify for this guarantee all doors and windows purchased must be upgraded to have our sealed units fitted with laminated glass to either the inner or outer pane. Please note that this option is not available on all glass designs.