Launched in April 2021, and modified in 2025, the Origin OS-29+ sliding door brings improvements in profile, thermal perfomance and a flush stacking feature. As a partially bonded system, it is simpler to fit and glaze and comes with the legendary Origin quality, reputation, and guarantee. The downside is it is expensive compared to comparable doors with slimmer sightlines and more features.
Origin OS-29 sliding door
With the legendary Origin manufacturing quality and service, the 2025 Origin OS-29+ is slim at the central mullions, has standard dimensions elsewhere and follows some other sliding door brands in introducing the flush stacking feature. It is a great option for those not wanting the complexity of a fully bonded door, but there are slimmer, better and cheaper doors than this one.
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Pros
- The trusted Origin name and quality
- Widely available
- High Quality Hardware
- Flush stacking (with caveats)
- No longer needs to be triple glazed for new builds
Cons
- Expensive for what it is
- Not as slim as it's marketed
- Four panel designs still wobble
In preparing this review, we’ve seen the product in the North-West of England being installed, as well as studing the technical manuals and saw the product installed in a Gloucestershire showroom.
What is the new Origin OS29+ sliding door?
The OS-29+ is Origin’s latest version of its popular slim-mullion sliding door with a partially bonded construction. The previous model (OS-29) was identical to the existing OS-44 and OS-77 with the only difference being the 29mm mullion or interlock.
The OS-29+ now features completely redesigned profiles, different dimensions, a new range of handle textures and flush stacking. As is the case with Origin’s fantastic marketing, they’ll make you think they’ve re-invented the wheel with flush stacking. The reality is, it has been available with several sliding door brands already.
Yes, the OS-29 is new, but the entire range was due an upgrade, because all three models could only meet Building Regulations in a new build as a triple glazed product. So this new door has improved profile design and Origin claim “the most thermally efficient aluminium sliding door available on the market”. We will come to that claim later. What is good about this door is it provides a reasonable ‘slim’ central mullion and is a good solution for those put off by the price and complexity of structurally bonded doors, typically with a 20-25mm mullion.
What is new with the Origin OS-29+?
Origin has never been that innovative with the design of its profiles, keeping the construction of these as simple as possible. The previous model wasn’t that great in its thermal performance and it would appear this is the reason this door has had a revamp, rather than bring out an entirely new door. That said, the design changes from the old profiles to the new is noticeable.
Looking at the profile drawings, it’s obvious Origin has chosen a simpler route to thermal compliance. The most noticeable changes is the increase frame depth, the insertion of thermal components and spacers and a substantially deeper polyamide thermal break compared to the previous model. Every profile in this door has been changed in some way to accommodate these inserts and insulation. Given the weaknesses of the OS-44 and OS-77 to meet thermal requirements well, these frame changes will probably follow onto these models in due course as well.
The 29mm interlock has also had it’s profile design changed and its a lot more complex than the original. Also visible in the profile design are new beads. In short, Origin has had to beef up the door to meet thermal performance. Here is how it compares to the previous model.
| Specification | Origin OS-29 | Origin OS-29+ |
|---|---|---|
| Outer Frame Face Width | 50mm | 50mm |
| Double Track Threshold | 143mm | 167mm |
| Triple Track Threshold | 213mm | 249mm |
| Underside of Frame to Bottom Rail Glass Line | 114mm | 116mm |
| Underside of Frame to Top Rail Glass Line | 114mm | 116mm |
| Trickle Vent Frame Extender | 35mm | 35mm |
| Locking Jamb Depth | 143mm deep | 167mm deep |
| Triple Glazing Option | 36mm | 44mm |
Design and Aesthetics
The OS-29+ keeps the same inline sliding operation as before—this is not a lift-and-slide door. The central mullion remains at 29mm, and it’s the most visually defining element. However, compared to other doors on the market with even slimmer sightlines and more advanced mechanics, the OS-29+ remains a solid but not standout choice for minimalist projects.
Flush stacking is now available, allowing the sashes to slide behind one another with minimal projection. That said, the external handle must be swapped for a colour-coded flush version to achieve this. This detail is often glossed over in marketing, but it affects the end-user experience.
From a hardware perspective, Origin offers a broad range of handle designs, including its new Signature Knurled handle available in multiple premium finishes. The overall system appearance is refined, with colour-coded gaskets, matching interlock caps, and clean lines supported by concealed running gear.
Over 150 RAL colours are available, with standard finishes like Anthracite Grey and Jet Black offered on 20-day lead times. Special finishes take around 30 working days.
Origin OS-29 comes with an inline sliding operation only – that means the doors sliding on their track in the push pull action.
Read more about the differences between this method of sliding and the modern advanced lift and slide.
The Flush Stacking Design
Flush stacking of two and three panel sliding doors has been available for a while now with brands such as Sunflex and Cortizo.
It’s a great feature that makes an open set of doors look neater when fully opened.
The flush stacking design does cause a finger trap situation which can be quite nasty if you’re not careful. Other suppliers provide a warning sticker with a flush stacking door. Always open the doors slowly and with care. Children opening and closing the doors should be supervised.
Technical Information
You can get the full information from the trade area of the Origin website. However, the OS-29+ is a clear upgrade over its predecessor in terms of profile construction. Every section has been re-engineered to improve insulation. A deeper polyamide thermal break, additional spacers, and insulation inserts have been added across the frame.
As is always the case with claimed U-Values for any door, be sure to check with what glass specification you get the overall product U-Value. All system companies and Origin is no exception love to use the term “U-Values as low as” which doesn’t mean a lot when it comes to telling you what U-Values you’ll actually get. But here are the details from Origin:
- U-values as low as 0.78 W/m²K with triple glazing
- Max sash weight: 200kg
- Max sash size: 2.2m wide x 2.62m high
- Up to six panels per set
- Maximum overall width up to 13.1m
- Min/max frame heights: 1015mm–2700mm
- Min/max sash widths: 492mm–2200mm
- Passed 50,000 lead sash cycles (equivalent to 25 years of use)
- Air permeability: Class 4, 600 Pa
- Water tightness: Class 7A, 300 Pa
Anyone familiar with the existing Origin sliding doors range is getting a very similar door.
Security and Energy Efficiency
The Origin OS-29+ is PAS 24 certified and fitted with a multi-point lock and 3-star diamond cylinder. The multi-point locking mechanism has six engagement points and has been upgraded to meet modern security standards.
For energy efficiency, the OS-29+ now meets current Building Regulations for both new-build and replacement applications—without needing triple glazing. This is a key improvement over the old OS-29. A deeper frame, thicker thermal breaks, and new cavity gaskets all contribute to its improved performance.
- PAS 24 Certified
- Multi-point lock with 3-star cylinder
- U-value: as low as 0.78 W/m²K (with triple glazing)
- Energy Rating: B to A+
Is the Origin sliding door any good?
Suitable for new build or replacement sliding door installations, the Origin OS-29+ sliding door comes as two, three or four panel sliding doors .
The overall build quality, fit and finish is the now reliable Origin quality and excellent service to its big installer base. Now Origin has it’s own paint facility, which brings another step in-house control to the company.
Origin is one of the best when it comest to marketing as is it’s marketing language. But some of its language can imply you are getting a massively better product . You’re not.
Origin loves to use the phrase “premium grade aluminium”. There is no such thing when it comes to the quality of aluminium profile for windows and doors – aluminium can only be architectural grade.
The second is the recent Qualicoat Approval which is an international standard for powder coating application, the manufacturing of the powder itself, aluminium pre-treatment before coating and other services. We’ve heard sales people in an Origin showroom state that only Origin is Qualitcoat Approved in the UK which is nonsense. Here is the complete list of all Qualicoat members which includes virtually every major systems house in the UK as well as independent powder coaters and finishers.
Marine-grade powder coating is also widely avalable but be careful if your property is in a coastal or exposed location, because marine-grade is not the same as a fully insured finish as we explain in this article. However Origin is now the coater and is in the position to provide the full marine warranty not just marine grade thickness, if needed.
How much does an Origin OS-29+ sliding door cost?
The price of an origin sliding door depends on where you buy it from, the buying power of the installer, their installation charges, fitting costs and other factors. Size, colour, glass specification also affects the price. Get in touch for your nearest Origin dealer.
Approximate prices excluding VAT for Origin sliding doors, supplied and installed in a black or grey finish are:
OS-29+ two-panel 1800x2200mm £4400
OS-29 three-panel 3000x2200mm £6100
OS-29 four-panel 4200x2200mm £7800
Other products to compare with the OS-29+
Several sliding door brands on the market make claims about the slim nature of their doors. Context is everything with claims about sightlines. The Origin OS-29 sliding door is in no way one of the slimmest in the context of overall sightlines, but it is thin at the door mullion. Many brands are slimmer both in terms of mullion sightlines, overall frame depth, head, track and side jamb face dimensions.
Here is our table of the UK’s slimmest sliding doors at the door mullion.
Most if not all of the marketing messages around slimness relate to the door mullions. As a semi-dry glazed system, the OS-29 is certainly amongst the slimmer mullion doors, at 29mm. However, also using the same bonding method at the mullion, there are slimmer doors and alternative options to consider, many of these also cheaper than Origin from our research and feedback into the website.
Top Choice – Schüco ASE 51
The ASE 51 PD Panoramic Sliding Door brings the outstanding Schüco brand name at a more affordable price point. This new sliding door looks fantastic, is very well designed, slides effortlessly and has the slim sightlines today’s customers expect.
With its pleasing minimalist design, you also get the legendary Schüco performance and reliability. The interlock is just 2.5mm wider, with a thinner frame face dimension arguably the top door brand at a very affordable price.
Also recommended as alternatives to the OS-29+ and worth getting a comparable quotation:
- Aston Architectual AS-20 and AS-25, semi-structural bonded and with soft-close facility. 20mm and 25mm mullion respectively.
- Alumil M650 Phos with a 25mm mullion
- Smart Systems Invisoglide with a 20mm mullion
- Sunflex SVG20 and SVG30 sliding doors – significantly better engineered and styled
- Cost effective and also good is the Exlabesa sliding door with a 30mm mullion.
The reality is we are talking millimetres difference. Moreover, the marketing messages around sliding door sightlines are beginning to confuse buyers and in our view bordering on misleading them too, implying they’re buying an ‘all-round slim’ door. The most important with any sliding door choice is it’s suitability for its location. This door is perfect for most installations that will mostly be at the back of a house in a suburban street. However, this is not the door for a cliff top exposed to wind, rain and significantly more stress.
For those specifically interested in the mullion sightlines of patio doors, you can see who makes the slimmest sliding doors in the UK whether dry glazed, bonded or semi-dry glazed.
Origin OS-29+ sliding door. More information and where to buy
Origin has the advantage of several hundred showrooms around the UK, and many of their installers are loyal to the brand and rightly so. The serivce and support, quaity and reliability are excellent,
However, ignore the marketing hype, there really is no ‘bad’ door on the market nowadays. Any well-made and properly fitted door will serve you very well.
Don’t disregard the thicker profile dry-glazed sliding doors. Often these are simpler to live with, more affordable, easier to maintain out of warranty as well. Lift and slide doors can be a better option in many cases as well.
There are now many good slidign doors on the market and the best way to get the right one for your home is to see them and try them out. Often how a door slides is the best indicator of it’s quality. The OS-29+ is good, but we think there are better doors out there for the money. That said, Origin products promise good lead times, service, manufacturing quality and reputation. Four reasons alone why these doors will enhance a property renovation project.
The OS-29+ is nor revolutionary but a much-needed upgrade that makes the product compliant with current Building Regulations while maintaining the Origin standards of manufacture and finish.
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