SUNFLEX sliding doors review

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Nick Dardalis

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There are many quality sliding patio doors on the market from many good brands, but SUNFLEX sliding doors provide probably the best of all worlds when it comes to sliding doors as a replacement for any dated patio doors or for a new extension. With a choice of sightlines, excellent overall design, the renowned Sunflex brand name and peace of mind in coming from some of the best door and window companies, Sunflex sliding doors are beautiful, functional, desirable and recommended. In this review we focus on the three sightline models available.

Sunflex sliding doors
sunflex grey sliding doorjpg e1543124113292

A choice of 20mm, 30mm or 83mm mullion sightlines, the ability to stack fully flush and a better overall appearance than bonded sliding doors makes Sunflex one of the best sliding doors you can buy and highly recommended.

Editor's Rating:


  • The flush stacking design
  • Sunflex reputation and quality
  • A simpler better door with a 20mm mullion
  • Inline or lift and slide design


  • Not available trade supply only

The SVG range of SUNFLEX sliding doors.

Our review focuses on the design, size capability and technical aspects of the products as well as where to use them. Several compelling reasons make SUNFLEX sliding doors this door worthy of consideration with systems such as Reynaers, Schuco and even the very latest ultra-slim sliding patio doors.

Made in the UK exclusively by Sunflex UK, SUNFLEX sliding doors use premium grade aluminium with polyamide thermal break, insulating the aluminium profiles. The aluminium profiles are then coated with a professionally applied colour finish in a choice of over 150 RAL colours, including dual colours, giving an alternative colour outside and inside.

Designed for double or triple glazing, Sunflex doors offer excellent thermal performance, weather protection, and their high-specification components ensure a light, smooth and reliable sliding action. The doors come in a standard inline sliding design with a push/pull operation and also come with the latest lift and slide design, offering additional features and alternative handle styling.

Within the SUNFLEX range are three models, essentially using the same frame profiles but differing at the all-important middle mullion. The SVG20 comes with an ultra-slim 20mm mullion or interlock, the SVG30 has a thin 30mm dimension, and then there is the SVG83 model with an 83mm mullion, offering a bolder or classically styled appearance and designed for when you need the largest possible sliding panels.

Four different handle options provide choices available in matching or , contrasting colours and satin stainless steel. Door colour options include grey or black colours as well as the full range of RAL colours or different colours inside and out.

Many common features are available across the entire SUNFLEX sliding doors range.

The flush stacking design

Few sliding doors on the market offer the option to open and stack flush fully. Other sliding doors fully open have a staggered opening with one panel partially in front of the other.

picture of open and stacked sliding doors
Few sliding door products open and stack fully flush.

SUNFLEX sliding doors, whether you choose the SVG20, SVG30 or SVG83, all come with this option. The benefit is a neater-looking door when fully open, giving you more of the available structural opening.

This feature is only available where the door locks from the inside only, although a standard opening comes when you want to unlock the doors from the outside.

High security and tested to the latest performance standards

All sliding door models are tested to the latest security requirements, such as Secured by Design ™ . You’ll get multipoint locking, security cylinders, robust sliding door handles and glass secured from the inside. Overall, SUNFLEX sliding doors provide a modern and secure sliding door proposition fitted with latest generation hardware, and good security features throughout.

The locking system on these doors has a five-point lock with mushroom headed cams, ensuring a tight seal and optimum locking point. Other security enhancements include internal glazing preventing removal of the glass from outside. The sliding panels also have an anti-lift feature. This prevents anyone forcing the panels up off the track.

Toughened glass comes as standard with the doors with laminated glass upgrade available.  

Flush sliding door tracks

Pocket and open corner sliding doors

All the sliding door models come with the option of a pocket sliding design, disappearing into a wall with the same flush stacking capability. Alternatively, the open corner design is either fully supported via a cantilevered roof or with a separate structural post.

Some of the best-looking steel-look sliding doors

There is no dedicated steel-look sliding door on the market. Instead door designers and manufacturers take a system and customise it with applied bars to the glass and using specially made glass units.

The SVG20 model in particular creates visually appealing doors in the steel look, thanks to its neat styling, thin mullions and overall great design.

SUNFLEX SVG20 Sliding Doors

svg20 wickhamway 002
The SVG20 offers the popular 20mm mullion with a slimmer and neater look.

The slimmest sliding door at the mullion within the SUNFLEX sliding doors range is the SVG20 model. This offers arguably one of the most compelling sliding door with 20mm mullion propositions compared with the more complex bonded sliding door brands such as Cortizo and arguably better styling.

Ultra-slim sliding patio doors are the newest type of product on the market offering sightlines from 17mm up to 35mm or more.  These super thin, structurally bonded doors cost more and come with other manufacturing and installation considerations.  Conventional sliding doors like the SVG30 or 83 are dry glazed meaning unlike the ultra-slim doors, glazing is done on site, not in the factory.

The other visual consideration with structurally bonded patio doors, as good as they are, is the very deep interlock. It might look nice and slim face on, but projects deeper internally, often by up to 150mm or more. This is for structural reasons as well as acting as a door handle with many systems.

SUNFLEX SVG20 sliding doors look slim when viewed from any angle and offer a much better-looking door at the all-important middle mullion.

SUNFLEX SVG30 Sliding Doors

slimline patio doors
With a still slim interlock is the more affordable SVG30.

With a 30mm interlock, the SVG30 offers a far simpler-made yet premium sliding door.  Structurally-bonded products such as the Infiniglide 6 Sliding Door, Alumen Cor-Vision Plus, and Schuco ASS70 PD Panorama all offer 24mm and 30mm interlocks.  Even the Express Bifolds slim door products you’ll find may cost more with a similar sightline.

Therefore, a product like the SVG30 offers similar thin sight lines of the much more expensive structurally bonded products at far less cost and in our view, looks aesthetically similar without the deep projecting mullion. See both types of doors and we think you’ll agree, there is not much difference.

The choice of the product mainly comes down to the sizes of the doors and the technical capability. If sight lines are important in choosing a sliding door or a bifolding door, both the SVG30 and SVG83 provide thinner aluminium sight lines than even the 115mm sight line SUNFLEX bifolding doors lead the market with.

SUNFLEX SVG83 Sliding Doors

sunflex sliding patio door
The SVG83 contemporary sliding door offers a bold look.

Offering a bolder a more prominent style are the SVG30 doors within the SUNFLEX sliding doors range and the advantage of these is their large size capability.

For those embarking on a Grand Designs type extension with bigger sliding door panels, then the SVG83 goes up to 3.2m high – again subject to technical considerations.

Do not discount doors with a thicker middle mullion – often this can be exactly the look you need across a larger sized opening.

open corner sliding doors
SUNFLEX sliding patio doors designed as a frameless open corner and with a flush triple track threshold.

SUNFLEX sliding doors review – conclusion

With premium manufacturing quality, a high-end overall style, a great brand reputation and available from professional home improvement firms, SUNFLEX sliding doors are a fantastic investment, whether you are looking to replace dated door or need the best possible look for a new extension.

SUNFLEX installers are all carefully vetted and approved by the manufacturing company, providing peace of mind that these advanced doors come with a professional installation, a quality guarantee and the exclusivity you only get with doors made only by one company.

We can help put you in touch with SUNFLEX sliding doors installers near you, use our contact form to get in touch.

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