One very topical subject is trickle ventilation. What is a trickle vent? A trickle vent is a device that allows fresh air to circulate naturally through a room and allow polluted air out. They are designed to improve the quality of air in a room and help prevent condensation, mould growth and dampness. Incorporating trickle ventilation in habitable rooms is now a Building Regulation requirement. Incorporating trickle vents in virtually frameless sliding doors can be a problem, however, Sunvista can do this even if the frame is fully concealed.

Security is one of the most important considerations when selecting this type of product and Sunvista is as secure as any minimally framed sliding door system available. It is specifically designed to suit the UK security requirements and its unique multipoint locking system has passed the extremely intensive *PAS24:2016.

There are four particularly vulnerable areas of a sliding door system and Sunvista addresses them all.

Locks: All Sunvista doors are fitted with three 5mm thick, stainless steel, double hook, multipoint locks which are strategically concealed within the frames. The location of these is not visible from the outside meaning that would be intruders would not know where to attack.

The locks are operated by a single, easy to operate, sliding handle. Don’t be deceived by the simplicity of the locking handle; the Sunvista locking system is very secure and complies with UK insurance requirements for glazed sliding doors. It also provides an easy means of escape. There will be no need to hunt for keys in the event of an emergency. The discreet locking handles can also incorporate alarm contacts, if required. See the question below regarding alarms.

Lifting doors out: All doors are fitted with anti-lift devices.

Lever/crowbar attack: Part of the PAS24 testing involves test engineers attacking the frame profiles with nail bars, hammers and screwdrivers in various locations to try and break in. There is no point in having secure locks if the profiles can be easily removed. The test engineers seem to take it as a personal challenge to try and break through the door security, however, in the case of the Sunvista system, they failed.

Glass strength: As a minimum, double glazed units installed will comprise two leaves toughened glass. Toughened glass is up to five times stronger than standard float glass and is extremely impact resistant. Laminated glass is also available, and this might be a requirement if the project is a new build property because the doors will probably have to comply with Part Q of Building Regulations.

*PAS24 is a UK test where doors are independently tested for their security credentials. The tests assess the ability of the door or window to resist the type of attack normally associated with casual or opportunistic burglars The testing does not only consider the security aspect, but it also includes weather testing and durability for long term use. The Sunvista concealed wheel carriages have been designed and engineered to be maintenance free using corrosion-free components and these, as well as the integral and elegant locking handles have been tested to 50,000 actions.

The Sunvista floor track is designed to be fully recessed within the floor and inside transition free. Even though fully recessed, water should not breach the simple but effective drainage system. The recessed base track incorporates an integrated drainage chamber system which ensures that even during the heaviest rainfall water drains externally into a concealed in-ground drain or into a proprietary Sunvista, narrow gutter (see below) which is only 35mm wide and can be powder coated to match the frames. This will be very helpful to your builder.

The base tracks are fixed on bespoke adjustable brackets and no fixings ever penetrate the track which ensures that water can never seep through.

Sunvista does not rely on packing that can shrink or move over time. The base profiles are fixed on solid, adjustable, steel base plates are installed which once set will never move and this will ensure that the tracks always remain level. The base track needs to be perfectly level to ensure the tracks drain properly over the length of the track. If the tracks are not level, water will find the lowest point, and this could create over capacity in that area.

The Sunvista system was recently tested by BSI and achieved a water test result of Class E750. The Senior Engineer at BSI commented, ‘Your water class achieved yesterday was the highest I have ever seen on a patio slider and I have seen many patio tests in my time at BSI’.

The Sunvista system was tested at the British Standards Institution in March 2021 in accordance with their testing criteria and following the testing their senior test engineer commented ‘Your water class achieved yesterday was the highest I have ever seen on a patio slider and I have seen many patio tests in my time at BSI’. The other tests were equally as impressive. Test data as follows:-

Watertightness: Class E750 (the class up from 9A) in accordance with BS 6375-1:2015

Wind Resistance: Exposure Category C3 (1200Pa) in accordance with BS6375-2:2009

Air Permeability: Test pressure Class 4 in accordance with BS 6375 – 1:2015

The Sunvista system was independently tested for security and achieved PAS24; 2016. This is a UK test and is the most advanced security testing method for residential windows and doors in the UK. The Sunvista was tested as a door not just as a window which has a lower testing regime.

PAS24 is a requirement under Document Q of the Building Regulations, if your project is a new build. The European standard RC2 does not meet this security standard and will not ordinarily comply with Part Q requirements.

Very little.

Sunvista has been designed to be virtually maintenance free. The concealed wheel carriages have been designed and engineered to be virtually maintenance free, using corrosion free components and have been tested to 50,000 opening cycles. The integral and elegant locking handles have also been tested to 50,000 locking actions.

The wheel carriages incorporate brushes which will sweep most debris to the end of the tracks and an occasional wipe over with a dry cloth is all the maintenance that should be necessary. NEVER use grease or oil-based products which could attract dust.

It is essential that during the building work, no sand or cement dust is allowed to settle on the tracks as it could block the brushes and possibly prevent the doors from sliding smoothly. One simple precaution is to insert foam pipe lagging in the tracks. This is soft, effective and will not cause damage to the powder coated finish.

The normal maximum individual sliding panel size is 3500 x 3200mm, however, this can be exceeded, if required. Fixed panels including frameless glass corners are available up to a width of 6000mm. The overall track lengths can be up to 30 metres long.

Sunvista comes with an uncomplicated ten-year warranty. Click here to view the warranty.

Any variety of configurations using one, two, three, four and even five tracks can be accommodated including fully opening corners, frameless glass fixed corners, pocket doors, bi-parting doors, central opening panels and doors that can slide outside a building to create space. Please refer to our 'typical details' which indicate some of the more usual options available. Sunvista is our product and is made in-house, therefore we can be flexible with designs. If you require something different to those shown or a bespoke design, please ask. For more information on some of the configurations available please click here.

Depending on the orientation of the glass doors, additional solar protection might help. The further away from due south the glazing faces, the problem of summer overheating is reduced. UV rays are also much stronger when the sun is high in the sky. Neutral (non-tinted and virtually invisible) solar control coatings can be incorporated within the insulating units, and this will help protect your home by blocking out harmful UV rays from the sun. These will not noticeably affect the level of brightness but will help to reduce solar gain.

The most popular solar control coating is SN 70/35. This is because it is effective in terms of solar control and does not reduce light transmission by much. Below is an image which indicates basic performance data.

All solar control glasses have a slight tint, however, the SN 70/35 is neutral and does not impact the view when looking out. Below is an image of an installation in which this glass was used. As you will see, the view out is not dramatically affected.

The Sunvista system is manufactured on our premises. Depending on the complexity of the project, the type of insulating units selected and our workload at the time of order, we would expect to fulfil most orders within 6 - 8 weeks of receiving signed off drawings. Please note that we cannot proceed with manufacture until our drawings have been signed off as approved.

Blinds do not yet form part of the Sunvista system. Separate blinds which provide privacy and shading, such as those manufactured by Luxaflex, can be installed into recesses inside or outside the frame. Please see just one example below. There are other options available.

The aluminium frame profiles can be powder coated in over 200 standard, non-metallic RAL colours which are available at no extra cost. Click here to view some of the standard colours. Please note that colours and shades can vary slightly. Metallic colours or anodised finishes are available at an additional cost.

A 'U' value is a calculation of the amount of energy that can escape through the external envelope of a building. The energy loss is calculated in Watts per m² Kelvin (W/m²K). The lower the 'U' value the better the thermal performance.

Until recently the glazing element would have been one of the weaker elements when compared to more solid materials, however, Sunvista installs high quality insulating units as standard, with warm edge spacer bars, soft coat low ‘E’ (low Emissivity) coated glass and argon gas filled cavities that achieve a centre pane 'U' value of 1.1 W/m²K as standard.

Low ‘E’ glass is essential for all double glazed units to achieve the thermal performance criteria demanded by Building Regulations Part ‘L’. Low ‘E’ glass has an ultra-thin coating on the internal face which reflects the heat to its source.

A window is not like a brick wall where the focus is on keeping the cold out and the heat in; efficient insulating units can contribute more energy to the heating of the building than is lost through the window.

Sunvista is an extremely thermally efficient door system which combined with high quality doubled glazed units, the system will achieve excellent overall thermal values.

Noise pollution has become an omnipresent health hazard particularly in urban locations or in the proximity of railways, roads and airports. Sunvista double glazing provides good sound insulation, especially as all units have warm edge spacer bars which absorb more noise than traditional aluminium spacer bars. However, if noise is a particular problem Pilkington 'Optitherm' acoustic glass can be incorporated. Click here for more information.

Unlike many others, Sunvista doors are supported on only two points, rather than sliding on a continuous row of wheels in the tracks or under sliding doors which can vary in height and detrimentally affect the sliding operation.

Sunvista sliding doors run on bespoke wheel carriages which incorporate concealed, low resistance, top quality, stainless steel ball bearing rollers that create a smooth and easy sliding operation. These rollers are designed to be virtually maintenance free.

One extremely important issue regarding the sliding operation of the doors is that the base track must be level and remain level otherwise the doors will not slide well. Sunvista does not rely on packing that can shrink or move over time; fully adjustable, steel base plates support the base tracks which once set, will never move and this will ensure that the tracks remain level.

Another reason for ensuring the base track is perfectly level is to ensure the tracks drain properly over the length of the track. If the tracks are not level, water will build up at the lowest point and this could create overcapacity in that area.

Yes, Sunvista doors can be automated.

Doors can slide into pockets on one or both sides and on one, two, three or four track systems. They can even slide over the outside of the building if there is no room for an internal pocket. Please refer to our 'Technical Details' section for more information.

Most alarm contacts and sensors can be incorporated within the system including Grade 3 alarms, however, Sunvista has an advantage over other systems because it can incorporate sensors within the locking system that do not only indicate that the doors are in the closed position, but the alarm will not set until the doors are properly locked.

We can work with your alarm company and, depending on the component type and size, will try to accommodate your components within the frame. Please let us know your requirements and the category of security required.

Bi-folding doors do not currently form part of the Sunvista product range but can be supplied in other systems.

If Sunvista is installed at a high level and is required to act as a barrier from falling, laminated safety glass should be installed as part of the insulating unit and will provide anti-fall protection. Frameless 'Juliet' and other types of balustrades can be incorporated as another means of anti-fall protection.

The already impressive ‘U’ values can be improved slightly by introducing an invisible, high-performance film which acts as the third leaf of a triple glazed unit.

Triple glazing would not improve the weather performance because the perimeter seals would be the same whether double or triple glazed, however, there would be a small financial saving. In terms of money, based on a ‘U’ value difference between double and triple glazing of 0.4W/m²K (0.7W/m²K triple glazing compared to 1.1W/m²K for double glazing) the energy saving for a window 2000 x 2000mm, assuming a rate for gas of 6p per kWh, would be approximately £15.00 per annum.

It is not required to. FENSA stands for the Fenestration Self-Assessment scheme which was set up by the Glass and Glazing Federation to ensure that replacement windows meet the Government’s Approved Documents Parts L1B and K4 (England) or N (Wales) (safety in relation to impact). The Sunvista sliding door system does not come under the category of ‘replacement windows’ and as such the installer is not required to be FENSA registered. However, it should be noted that Sunvista more than meets these requirements.

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Only properly trained installers are allowed to install the Sunvista system. We need to be confident that the product is installed properly and in accordance with our installation instructions and that you, our customer, will be satisfied with the operation of Sunvista for years to come.

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Unless agreed otherwise our standard terms are 25% of the contract value payable with order or receipt of signed contract; 65% payable ten days before installation with the balance payable on completion of the work. All payments are to include VAT at the appropriate rate.

The Sunvista system not only looks good but is sustainable too. Extended life spans, low maintenance with maximum recyclability and excellent thermal efficiency help to make use of the world’s limited resources.

When the Sunvista system was developed 10 years ago, the decision was made to source all components and materials from the UK to reduce our carbon footprint and that is still our philosophy. Even the Sunvista aluminium framing profiles are extruded in the UK. No long journeys from China or Russia because the aluminium profiles are extruded in Loughborough. The insulating units are manufactured in Luton and the ancillary components such as the wheel carriages are manufactured in London.

One of the other ways that Sunvista will help the environment is in the long term. Part of our testing is related to the longevity of the system. The doors have been tested to open, close, lock and unlock 50,000 times which demonstrates the durability of the wheel carriages and locking components. If you were to assume that each set of doors is opened twice a day, every day of the year, that is a lot of years! Sunvista doors would not have to be replaced for many years.

This video shows a Sunvista door closing against a wall and locking, then unlocking.

Do not be deceived by the simplicity of the attractive and discreet locking handle (photo below). This merely activates what is a very secure, multi-point locking system. The Sunvista locking system complies with UK insurance requirements for glazed sliding doors. It has been specifically designed to suit the UK security requirements and its unique multipoint locking system has passed the extremely intensive PAS24:2016 standard, which is the most advanced security testing method for residential windows and doors in the UK.

Registered key locks can be incorporated in the locking handles, if required, however, the Sunvista system was tested to this high standard without using keys and provides a means of escape in the event of an emergency without having to look for keys. The locking handles can also incorporate pencil alarm contacts, if required, that can be connected to your alarm system.