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keller minimal windows +4 large sliding doors

Triple Glazed Sliding Doors

The minimal windows 4+ system, exclusive to IQ Glass within the UK, is the most technically advanced slim framed sliding glass door available in architectural glazing.

Using an engineered triple glazed unit, and maintaining a slim aluminium frame of only 26mm, you can create large sliding glass doors of up to 4.5m high and 12m2 for each sliding panel with exceptional levels of thermal performance and weather resistance.

There are no restrictions on the number of sliding tracks you can have. Keep in mind that each sliding track is approximately 88mm deep with a two-track sliding door at 174mm deep and a triple track slider at 269mm deep.

As well as increased levels of resistance to air permeability, water and wind loading these large triple glazed sliding doors have also undergone specialist testing for resistance to hurricane levels of cyclic wind and driving rain. The hurricane tests also incorporated missile impact testing to recreate the experience of objects being thrown in a storm.

You can see from the impressive resume of the minimal windows 4+ that if you are looking for a high performance, minimal sliding glass door the minimal windows 4+ far outstrips the rest.

Oversized Glass Doors

With a maximum sliding glass door of up to 12m2 you can create extensive walls of sliding glass with a thin vertical frame of only 26mm keeping a frameless surrounding finish.

Using a triple glazed unit with a Ug value of 0.7 W/m2K it is very possible to achieve large sliding glass walls with a Uw value of 0.8 – 1.1 W/m2K depending on the configuration and size of the sliding doors.

The minimal windows 4+ has been fully detailed and designed to include a discrete locking device, high volume drainage and hidden automation as required whilst maintaining that minimal design finish that is created from the minimal windows system.

These triple glazed sliding doors are designed to be opened manually however if each sliding glass panel weights over 500kg then we may recommend including an automated drive to open the doors automatically. This motor can be hidden within the ceiling void internally for an invisible finish.

The number of sliding panels you can have is nearly endless with 2, 3, 4 or more tracked sliding doors possible. Pocket doors, opening corners and Juliet balconies are also possible adaptions that can be made to the triple glazed sliding glass doors enabling them to be adapted to almost any design project.

keller minimal windows +4 Oversized sliding glass doors


keller minimal windows +4 corner pocket sliding door


Our oversized triple glazed sliding doors are perfect for exposed areas of the UK where higher levels of thermal insulation, wind resistance or water resistance are required.

All EN testing was carried out at the Rosenheim Institute in Germany with the Hurricane testing being undertaken at the Vinci Technology Centre in 2014.

Air Permeability: Class 4 in accordance with EN12207

Water Resistance: Class E1050 in accordance with EN12208

Resistance to Wind Load: C5 in accordance with EN12210

Thermal Performance: Uw value of 0.8 - 1.1 W/m2K with triple glazing (depending on the pane size and configuration)

Security: WK2 in accordance with EN1627

Acoustic Reduction: Rw (C; Ctr) up to 43dB(1-;-5)

Barrier Free Accessibility: DIN 18040-1, DIN 18040-2

Hurricane Resistance Testing: Cyclic Wind Pressure Testing to 3510Pa,

Static Wind Resistance +/- 4500Pa Wind Pressure in accordance with TAS 203 and 202.

Impact Resistance: tested for large missile impact at 15.5 m/s in accordance with TAS 201.

Locking & Ventilation

The minimal windows 4+ operates with a standard two-point thrust lever locking handle for secure internal locking.

When turned the thrust lever handle sends steel shoot bolts from within the 26mm vertical frame into precast locking positions within the ceiling and the floor.

This internal mechanical lock has been tested to WK2 burglar resistance class at Rosenheim in Germany. Alternatively an electromagnetic lock can use used.

In some instances an external key lock can in integrated provided that there is adequate structural wall space to allow the external locking mechanism to be installed.

If ventilation is required within the triple glazed sliding glass wall IQ can install our slot aeration system into the minimal windows 4+ installation. By providing two extra locking positions you can then slide the triple glazed doors open to a 20mm or 40mm ventilation gap and lock them in this position.


keller minimal windows sliding glass doors
keller minimal windows +4 Large Sliding Patio Doors


If your triple glazed sliding doors weigh over 500kg per sliding unit we recommend that the sliding glass wall be automated. The size of the motor will depend on the running length and overall weight of the glass panels to open.

There are three basic motors suitable for the minimal windows 4+; the MOT 800, MOT 2000 and MOT 2000 IP. IQ Glass will specify the exact motor and size to be used on your project in relation to the weight of the sliding glass doors, the usage of the door and the length of the sliding run.

Motors for the minimal windows 4+ are installed internally and can be hidden within the internal ceiling void to maintain that minimally framed design that is strived for.

Control of the automated can be operated via a wall switch or remote control as requested. The operating system can also be integrated into your smart home automation systems if such system is installed within the property.




The minimal windows 4+ sliding glass doors can be designed to open on a corner leaving no framing at the connection. These corner connections do not have to be 90 degrees and could also be designed as an inverted corner for courtyard spaces.

When closed the male and female aluminium connecting frame on the corner will measure approximately 100mm x 100mm.

Pocket doors are also possible from these advanced triple glazed sliding doors. Using this adaption you can slide all triple glazed sliding units away into a hidden pocket.

The size of the pocket required to hide the sliding doors will depend on how many triple glazed panels are within the design and the number of tracks within the configuration. For instance a two track sliding door will require a pocket that is at least 180mm deep depending on the couplings required to the glass elevation and wind loads. IQ Glass can easily calculate this for you.

Frameless Juliet Balconies are also possible with the integration of a frameless glass balustrade within the aluminium frame. The frameless glass balustrade sits seamlessly within the sliding door frame to ensure it is invisible when the doors are closed. When open the structural glass balustrade creates a robust barrier from level changes.

ASK US ABOUT OUR minimal windows 4+ large sliding doors


Commercial use

Improved Performance

Many projects around the UK now have to adhere to tougher performance standards in order to achieve the government’s goals for CO2 emissions and environmental standards.

As such higher performing building materials must be used to ensure that new buildings reduce heat loss and also create an effective barrier between inside and out.

Due to the minimal windows 4+ enhanced performance testing it is highly suitable for these projects where higher performance standards are required.

With a greatly improved resistance to water and driving rain these triple glazed sliding doors can even be used as part of the façade material on luxury residential developments in London where high levels of water tightness are required.

Our hurricane resistance testing also shows the system’s ability to stand up against high winds and the triple glazed sliding doors are often used on high storey buildings where high wind loads will be experienced.

Some city developments will be required to achieve a certain acoustic insulation value for the building in order to stop noise pollution. With the use of triple glazed units within the slim framing this creates an effective acoustic barrier with an Rw rating of 43 dB which can be increased with the use of specialist acoustic insulating glass units.

IQ Projects is the specialist commercial division of the IQ Group - www.iqprojectsuk.com

Featured Project

The UK's Buckingham Gate development in the heart of London is the perfect example of this systems ability to be used on high-performance buildings.

The multi-unit luxury residential development is located in the centre of London, a stone’s throw from Buckingham Palace. Minimal windows 4+ were used to the rear elevation of all the luxury apartments within the development and were classed as part of the façade material for the building.

This required the sliding doors, which were used to allow residents access to their own small balcony overlooking the city, to adhere to very high levels of performance for wind loading and water resistance.

As well as these three pane sliding balcony doors the triple glazed sliding doors were used to the upper floor penthouse suite and integrated with a frameless glass balustrade to create a Juliet balcony that mirrored the balcony door openings below.

The triple glazed sliding doors were continued below ground level to the basement living spaces. A multi storey light well was created to bring natural light to the large basement living spaces. minimal windows 4+ were used on all three sides of the light well with frameless Juliet Balconies to allow light and ventilation to these basement spaces.

View the full project case study in our project gallery here. 


minimal windows 4+ sliding doors - IQ Product Data Sheet

NBS - minimal windows 4 plus

minimal windows Premium Brochure


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