The Cortizo brand name is firmly established in the UK for its super-slim slider with a 20mm mullion, called the Cor-Vision. For those not wanting the structurally bonded product and looking for a more affordable slider, Cortizo 4700 sliding doors provide an excellent alternative in a modern style that’s not too chunky either.
Background information on Cortizo 4700 Sliding Doors
Cortizo as a systems company originates from Spain and has a heavy presence in mainland Europe. It’s been operating in the UK for around a decade and quickly became for manufacturers and installers, the go-to product for slimline sliding doors, available now under many different brand names but essentially the same system.
Skyglaze in Surrey were the first company to bring the Cortizo system into the UK and invest in the system. In the years that followed, this brand has arguably driven other system companies to also bring out slimline sliding doors, especially with a 20mm mullion and interlock, although this type of door design has its comprises and needs careful consideration.
Over the years, Cortizo has grown into a formidable force in the UK now making inroads with their other brands, aluminium windows and the Cortizo 4700 sliding doors model.
The key features of Cortizo 4700 sliding doors
The main features of this particular slider cover security, weather performance, acoustics, U-Values and panel sizes.
- The lowest possible U-Values using 34mm triple glazed high specification units is 1.1Wm2K
- Double track frames are 120mm deep, triple track frames 185mm thick, all using 50mm thick door sashes
- Air tightness is Class 3, Water Class 7A and Wind resistance Class C5, based on a two panel door at standard sizes
- Door panels go up to 2.5m wide and 3.0m high although higher doors may need thicker profiles at the middle mullions
- The doors are tested to the latest security standards.
With horizontal sliding windows for dwellings being limited in type, the Cortizo 4700 sliding doors range goes as small as 600mm wide and 550mm high. It’s therefore available as a sliding window option. These smaller sizes are limited by the lock type available so it’s worth checking how secure they really are. For example, anything under 850mm tall only comes with a single point lock. Under 1850mm wide, a two-point lock. 1850mm to 2050mm with a three-point lock. Doors, therefore, over 2050mm high come with a four-point lock.
Sliding door configurations available with Cortizo
Available with double or triple tracks, doors come in two, three, four or six sliding panels. Two panel sliding doors work on a double track, three and more panels use triple tracks.
These doors can create standard doors as well as pocket sliding doors going into a wall. There’s no open corner design available.
The styling of Cortizo 4700 sliding doors explained
Close examination of the 4700 system manual and specifications reveals a product coming with a significant number of profiles and options. With these doors sold in Europe, there are, of course, doors needing shutters and flyscreens, not used in the UK. Many European doors are a non-beaded type, instead made around the glass. Therefore it’s likely the 4700 for the UK market does not make use of all the possible options available in other markets.
The system also comes with so many additional profiles, covers, caps, trims reinforcements, stackable panels etc, it’s not possible to cover every one. There are also more than 300 possible accessories available with the 4700 (we counted them). So for the purposes of this review, we can focus on the more standard configuration with glazing beads holding the glass in place and more standard frame, door panel and track/threshold profiles.
Overall, the styling of these doors is flat and modern. There are no soft curves to the styling of the frame, track or the aluminium on the sliding panels themselves. The head and track have 90-degree corners as the profile goes from one face to the other and the look is very pleasing indeed. As a result, these are superb in styling for modern extensions whilst staying timeless for the years to come.
How slim are Cortizo 4700 sliding doors?
Sold as a standard sliding door product, these doors actually have quite slim dimensions and even better, consistent sightlines all around. Using a two panel door as an example:
- Side frames to the glass line, 114mm
- Door head frame to the glass line, also 114mm
- Bottom track in a standard installation to the glass line, also 114mm
- Central mullion or interlock, 47mm
With heavy marketing of structurally bonded doors with a 20mm interlock, consumers are missing out on standard doors that actually give you more features, are for some, better in use and are only slim at the middle mullion. Some are actually thicker than standard doors on the surrounding frame and track.
As good as these slimline doors are, the truth is it doesn’t matter if the interlock on your doors is a little thicker. You’re getting similar sightlines everywhere else assuming a standard installation. And even if you’re choosing to set your sliding doors lower, all you’re getting is a slimmer door at the mullions and nowhere else. It’s also worth bearing in mind, that the thicker middle sightlines on other doors matter even less the larger the doors are.
So whilst you might be interested in the apparent appeal of a 20mm mullion, remember these are more expensive to buy, costlier to make, harder to transport with increased fitting costs as a result. The flush handles don’t appeal to those with dexterity issues either. There are also potential problems down the line when the doors are out of warranty, with repair and service and changing broken or failed glass units because of the bonded glass design.
Our point here is that doors such as these with a 47mm mullion are just as worthy of consideration and could save you a lot of money.
Hardware and colour options on the Cortizo sliding door
There are a few ways to configure the handles on the 4700. First is the option for handles on both sides, comprising a small lever handle that’s slim and attractive. This comes as a straight or cranked design in stainless steel or inox finish. Or, there’s the option of a handle outside and a recessed pull on the outside.
A further option exists for an embedded handle, that sits more flush on the door face. It does away with the more prominent handle. The downside is, it’s there to unlock the door only and not recommended as a mechanism to pull the door open. This comes in Black, White, three shades of Silver, Special Colour, Inox, or grey.
Also as an option is a separate cranked pull handle, available as a curved 125mm long or square 187mm long version. These come in Dark or Light Silver, Special Colour, Brown, Black or white.
Colour options are extensive with these doors and aside from the popular black, white and greys, are options for anodised finishes, textured powder coatings and more besides.
Other doors to compare with Cortizo 4700 sliding doors
Cortizo 4700 sliding doors can be compared alongside these similar products in terms of styling, price and features:
Smart Systems Visoglide sliding doors come with 35mm mullions and are a long-established, tried and tested product. The Origin OS44 is another product worthy of comparison with Cortizo with similar styling in many respects. Aluk also makes some excellent sliding doors, with similar lines, again worth comparing with Cortizo. In the South of England, also check out the aïr patio doors range, coming in with similar proportions, excellent handle designs and a 25-year guarantee.
Then we come to the Reynaers brand and the CP130 or CP155 are fantastic sliding doors again worthy of comparing alongside Cortizo.
Cortizo 4700 sliding doors – Conclusion and Summary
There’s no bad sliding door on the market today. Well made and fitted, all the current range of sliding doors come with excellent specifications. The profile quality, powder-coated finishes, glass, seals and gaskets, all meet current quality standards. Where doors differ is their styling, look and feel and in many cases brand reputation.
The balanced styling and design of Cortizo sliding doors make them ideal for replacing dated patio doors and especially for new extensions. There’s also a pocket sliding version but no open corner.
Cortizo 4700 sliding doors are recommended and offer premium looks and quality, suitable for all manner of property renovation. We like the trendy looking door handles, ultra-smooth sliding action thanks to stainless steel rails and comprehensive range of colours available.