What is the association between Sunvista and Compass Glass?

Compass Glass is the company that you would be dealing with. Sunvista is purely the trade name of one of the products that Compass Glass manufactures.

How secure is Sunvista?


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


Lifting doors out: All doors are fitted with anti-lift devices to prevent them from being lifted out.


Lever/crowbar attack: Part of the PAS24 testing involves attacking all profiles with nail bars, hammers and screwdrivers to ensure that they are not easily removable. There is no point in having secure locks if the profiles are easily removed. The test engineers consider it 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 of 6mm thick toughened glass; this 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 because the doors will probably have to comply with Part Q of Building Regulations.


*PAS24 is a UK test and is the most advanced security testing method for residential windows and doors. The testing does not only consider the security aspect, it also includes weather testing and durability for long term use. The 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. PAS24 is also a requirement under Document Q of the Building Regulations if your project is a new build. The European standard RC2 offered by many of our competitors does not achieve this security standard and will not comply with Part Q requirements.

How does the system drain if it is in the floor?

The Sunvista floor track is designed to be fully recessed within the floor and the threshold transition free. Even when fully recessed, it is extremely unlikely that water will ever 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 and in most cases into an Aco drain or similar which is concealed below the decking or slabs on the outside of the building seal. 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; solid, adjustable, galvanised 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.


It is essential that good quality damp proof membranes are installed to ensure a good seal between the Sunvista framing and the building structure.


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’.


Has Sunvista been tested?

Sunvista was tested to UK standards at BSI in April 2021 and achieved the highest categories they test to: air permeability Class 4, wind resistance Class C3 and for water tightness E750 which is the highest rating the BSI had ever seen for a sliding door.

What maintenance is required?  

Sunvista is a fully tested system and has been designed to be virtually maintenance free. Not only has Sunvista been independently tested for weather tightness and security but also for durability and long term use.  The concealed wheel carriages have been designed and engineered to be 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 that no sand or cement dust settles on the tracks as it could block the brushes and possibly prevent the doors from sliding smoothly. One precaution is to insert foam pipe lagging in the tracks. This is soft, effective and will not cause damage to the powder coated finish.

What are the largest panel sizes available? 


The normal maximum individual sliding panel size is 3500 x 3000mm, however, this can be exceeded, if required. Fixed panels including frameless glass corners are available up to a width of 6000mm.


What warranty is offered? 


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


What configurations are available from Sunvista? 


Any variety of configurations using two, three, four and even five tracks can be accommodated including fully opening corners and pocket doors. Please refer to our 'typical details' which indicate some of the more usual options available. Sunvista is our own 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.

With so much glass, will I have a problem with solar gain? 

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 which will help protect your home by blocking out the harmful UV rays from the sun. These will not noticeably affect the level of brightness and 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 the light transmission that 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.


How long does Sunvista take to manufacture? 

The Sunvista system is manufactured in our factory in south London. Depending on the complexity of the project, the type of insulating units selected and on our workload at the time of order, we would expect to fulfil most orders within six weeks of receiving signed off drawings.



Can blinds be fitted within the system? 


Blinds do not yet form part of the Sunvista system. Separate blinds which provide privacy and shading, such as those manufactured by Silent Gliss can be installed in recesses inside or outside the frame. See example below. 


What frame colours are available? 

The aluminium frame profiles can be powder coated to over 200 standard, non-metallic RAL colours which are available at no extra cost. Click here to view the 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.

What U-values can be achieved? 


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 in order 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 back 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.


Does the system provide good sound insulation? 

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 as standard, however, if noise is a problem Pilkington 'Optitherm' acoustic glass can be incorporated. Click here for more information.


How do the doors slide? 


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


One extremely important issue regarding the sliding operation of the doors – any ground-based sliding 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, galvanised 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 over capacity in that area.


Can doors be automated? 


Yes, Sunvista doors can be automated.   


Can doors slide into a pocket? 


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. 


Can the doors be alarmed? 

Most alarm contacts and sensors can be incorporated within the system including Grade 3 alarm contacts, 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 also not set until the doors are actually 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.


Are bi-folding doors available? 


Bi-folding doors do not form part of the Sunvista product range.

Does the system incorporate trickle ventilation? 


Trickle vents are very small openings normally integrated into window frames which allow air into the property. Gentle airflow helps prevent condensation, mould growth and dampness. Incorporating trickle ventilation in Sunvista sliding doors is not normally a requirement and is slightly complicated because the frames are normally concealed, however, with some minor modification it can be done. There are several other means of providing effective ventilation, extractor fans or air bricks are just two alternative means of doing this.


Can the system be used for high level applications? 


If Sunvista is installed at 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.


Can Sunvista be triple glazed? 


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 of 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 2.85p per kWh, would be approximately £6.80 per annum. If you only heat your house for six months of a year then this saving can be halved.


Does Sunvista come under the FENSA scheme? 

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. 


Can we buy Sunvista and install it ourselves? 


Only properly trained installers can 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.

What are payment terms? 


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

How will choosing Sunvista help the environment?

Apart from the excellent thermal values that the Sunvista system achieves, there are other ways that by installing the system it will help the environment. For example, when the Sunvista system was developed about 8 years ago, the decision was made to source all components and materials from the UK in order 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; the aluminium is extruded in Loughborough and our insulating units are manufactured in Luton. The wheel carriages and locking components are manufactured in London.


Sunvista fabrication is carried out in our own premises in south London.


One of the other ways that Sunvista will help the environment is in the long term. Part of our testing 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.