Slimline Doors and Windows

Slimline doors and windows, also known as minimalist, or ultra-slim doors and windows, comprise those products where the sightlines are smaller and less visible than regular windows and doors. With many of these slimline products, it’s the installation itself, with hidden frames resulting in minimal looks or appearance of frameless doors and windows.

The range of windows and doors marketed as slimline is frequently confusing. Consequently, it’s important to understand the difference between these many marketing messages and the genuine slimline and minimal or near-frameless product.

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Information about slimline or ultra-slim doors and windows

First of all, most of the ultra-slim doors and windows tend to be upper-tier systems and therefore cost more than regular windows and doors. Often these systems come with engineering and design intended for large sizes and contemporary architectural glazing. As a result, they come in more expensive systems.

Furthermore, doors and windows of this type frequently rely on the glazing for structural stability. In other words, the slimline aluminium may not provide the strength required owning to its smaller proportion. Alternatively, while slimline and ultra-slim glazing appears thin face on, at the same time it comes deeper than regular windows and doors. Again this is for retention of the performance, strength and stability of the product.

Exterior quality doors and windows come with insulated aluminium profiles and a good specification glass. Interior doors as well a screens come in two versions. One is an exterior grade door customised for interior use. Another is a dedicated interior system. These frequently come without any profile insulation as it’s not required. As well as this, interior products come single glazed too.

Virtually any type of door or window comes in a slimline version. There are presently no PVCu, timber or hybrid systems offering dimensions even close to these thinner products in aluminium.

Slimline and ultra-slim sliding doors

slimline patio doors in silver fitted to a garden room

Probably the best known and most asked-for amongst slimline doors and windows is sliding doors.

Sightlines start at around 16mm at the door mullions, therefore making these perfect for making an interior space bright, spacious and light filled. Most of these doors use the structurally bonded design.

All these doors have a frame. Hiding the frame and track gives the slimline appearance.

It’s easy to assume with slimline and ultra-slim sliding doors that the frame proportions are the same as the heavily marketed slim mullion. They’re not and especially when using the standard non-hidden installation method, you usually get thicker sightlines at the surround frame.

Importantly, slimline sliding doors come with several considerations and questions when buying. Installation, options and configurations often come more complex than conventional sliding patio doors. We’ve comprehensive information about thin-framed sliding doors, helping to buy better.

Ultra-slim bifolding doors

ultra-slim bifolding doors

When it comes to slimline bifold doors, these are typically doors with reduced dimensions at the door mullions.

Bifold doors can’t achieve the same dimensions as sliding model. We’ve put together a list of the slimmest bifolding doors brands based on their door mullion sightlines.

Other systems provide even more minimal systems using the slide and turn design. Then you’ll find premium models such as Sieger Lux and Fineline with alternative designs and even proportions.

Finally, some more advanced systems offer options for recessing the frame into the structure creating even more minimalist sightlines. However these also come with a price to match.

Thin profile floor-to-ceiling glazing and curtain walling

slimline curtain wallingfloor-to-ceiling glazing
Used residentially, creating large picture windows and incorporating slimline sliding doors

For modern homes, floor-to-ceiling glazing and curtain walling provide products spanning two or more floors.

These products utilise designs found in commercial facades. The construction involves box mullions of various sizes, assembled on site and creating large screens.

As well as providing large fixed glazing, these systems also integrate fully with sliding doors, bifolding doors and opening windows. The slimness of these profiles depends especially on several factors.

Location, wind loadings, supports and whether tied back to any floors are all essential requirements. Often, the larger the screen the thicker the mullions and frames. However, it’s common to find face widths of 50mm. Frame depths vary from 50mm up to more than 200mm for the largest facades.

Ultra-slim doors and windows

aluminium windows prices information image

Finding slimline windows for regular window replacements is often confusing for buyers. Many aluminium window brands already come with a slimline version. The sightlines you get depend on the frame and opening element combinations.

However, it’s often the case that many slimline aluminium windows easier providing thin windows for new build openings than providing slimline windows for window replacements.

In addition to standard aluminium windows, specialist installers provide high-end minimal framed ultra-slim doors and windows, specifically designed so the frame hides behind the structure and giving an all glass look.

Interior doors, windows and screens

slimline sliding doors in chigwell window centre romford showroom

For interior windows and screens, products designed for internal use frequently provide the best solution. Alternatively, exterior grade doors and windows do work inside the home in many situations.

The insulation and performance benefits of exterior windows and doors aren’t required internally. However, double glazing provides acoustic solutions when correctly chosen.

You’ll find interior ultra-slim doors and windows as well as interior products with specific systems, brands and designs. There are also near frameless versions available too. Steel-look glazing is one of the most sought after amongst these thin-framed products.

Deciding which slimline doors and windows are best

It’s important to, first of all, understand the makeup of aluminium windows and doors marketed as frameless. However, for these types of products, frameless, structural glazing and slim-framed aluminium provides the best end result.

It’s even more important to engage with a professional installer demonstrating a level of expertise and knowledge with ultra-slim windows and doors. These suppliers tend to go beyond regular window and door installations also providing a broader range of technical glass solutions, of which slimline products form just one part. Expect with these installers to find glazed links, glass balustrades, fire-resistant glazing, glass floors and other such advanced glazing systems.

These more advanced ultra-slim doors and windows are usually best designed, made and fitted by the same business. We do not recommend buying these products online. Manufacturing quality and installation by trained installers always provides the best result.

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16:42 30 Oct 23
Nick responded incredibly quickly to my enquiry (on a Saturday too!), and was able to offer invaluable advice on both aluminum systems and manufacturer / suppliers. Thanks Nick!
chris steerchris steer
16:18 09 Oct 23
Had a meeting with Nick during the grand designs show. Was extremely helpful and professional would highly recommend
Chris WesthorpChris Westhorp
19:55 13 Sep 23
Extremely helpful with pointing us in the right direction to find the products we required and suggesting firms that could reliably fit them.Nick was quick to reply and very detailed in his advice.Highly recommend reaching out to them.
Cathy GreenwoodCathy Greenwood
07:03 11 Sep 23
Update - A second email to nick for help on bifolds resulted in a detailed informative reply even on a Sunday ! This guy is so knowledgable and helpful .I approached Nick for an independent view on sliding doors v bifold and the different brand options . His reply was extremely detailed and prompt and allowed me to navigate this often confusing world in a much more informed way . Thanks so much Nick
Anthony CraigAnthony Craig
12:45 05 Sep 23
This is a must site for anyone looking for advice. Great service and very quick answers to questions. Nick has been of great help quiding us through the maze of aluminium products. Thank you
Philip DuffieldPhilip Duffield
20:24 26 Jul 23
I contacted Nick @ ATS for guidance on what aluminium sliding door systems would be suitable for an opening in an extension that is going to be both wide and tall. He came back really quickly with very detailed and incredibly helpful advice. He is clearly extremely knowledgeable about the systems on the market and their respective features and capabilities. If you’re feeling a bit lost by the overwhelming range of choices out there, I’d definitely recommend contacting him.
Dariush HekmatDariush Hekmat
17:25 19 Jul 23
Nick's advice is great. He is always quick to respond and spends time on responses, which really help to make an informed decision.
Alan FosterAlan Foster
07:51 12 Jul 23
Absolutely fantastic. Asked for advice about replacing Crittall (?) windows late last night and early this morning received 3 great suggestions and contact information for suppliers
Rachel LauRachel Lau
09:24 16 Jun 23
Fantastic website full of valuable and pragmatic advice about product selection and comparison: no other website gives information like this. Truly written for public interest. Don't hesistate to reach out to Nick via the mailing system. He responds very quickly, is friendly, and has very sound and high knowledgable advice. I have already shared this with my friend planning her own grand design.
guard Charlieguard Charlie
12:28 14 May 23
I emailed this company just on the off chance they could help me with new magnetic sliders for my patio door. They were not able to supply those but were so very helpful providing me with the name of a company who could. I am so very grateful at the great service. Dare say customers must be very happy. thank you so much.
Benjamin LewisBenjamin Lewis
10:06 04 May 23
Nick is very helpful indeed. Extremely knowledgeable on bifolds which was in relation to my query. Great website as well, some very useful articles. Particularly appreciated the article that lists all the major bifold options in order of their sightlines! Thank you!
P JonesP Jones
08:07 15 Apr 23
I asked Nick some questions about an installation we were considering and he replied within hours with some very useful suggestions that will probably lead us to using a different make and supplier. Thanks, Nick. Great work.
Nicholas WallNicholas Wall
13:18 02 Apr 23
Looking for fair and honest expert advice on all aspect of aluminium windows and doors? These guys will arm you with all the information you need to make the RIGHT choice in a highly complex, crowded marketplace. post a question and you will get a very quick professional answer you can rely on being based on fact. Thanks guys!
Giorgia SiriacoGiorgia Siriaco
16:25 21 Mar 23
After a lot of research to find doors that would meet our unusual size requirements and feeling increasingly uncertain about the best way to spend our small budget, I stumbled on the ATS website, and I'm so glad I did! I contacted ATS to request advice and Nick promptly replied with a wealth of information, providing us with options and relevant contact details. I only wish I'd found them sooner!
Carol NortonCarol Norton
10:01 17 Mar 23
I've been so confused about how to achieve the look I'm after, and going round in circles with various window/door companies, trying to get away from the huge chunks of plastic currently around my windows. I didn't expect an email to a company found through a Google search to really help - but I was desperate, so I tried. I'm SO glad I did. Finally I have clear explanations from ATS of where I've been going wrong, exactly what I'm looking for, and a list of local companies that might be able to provide it! The response has excelled my expectations and I feel as if I'm finally inching closer to a home with which I'll be happy and comfortable: thank you.
David NunnDavid Nunn
20:54 14 Mar 23
It is rare that I write reviews, however after my very positive communication with Nick - enquiring about suitable slim sash aluminium windows for my project, I felt that a review was definitely warranted. I can reinforce the many positive reviews posted so far, Nick was very quick to respond, providing comprehensive detail, with excellent independent advice.In summary, great service, thank you Nick.
Chantal AuerbachChantal Auerbach
13:04 09 Mar 23
Nick from Aluminium Trade Supply was incredibly helpful informative and pleasant to deal with. He responded quickly to emails and was very knowledgeable. Highly recommend being in touch with Nick if you are considering new aluminium windows or doors.
Lee JonesLee Jones
20:21 22 Feb 23
I dropped Nick at Aluminium Trade Supply an email re high security slim sightline bi-folds and their alternatives and he responded that quickly (and so comprehensively) that I felt bad I’d not paid him for his time!Nick Sir your product knowledge is outstanding and you are providing a level of service that goes wayyyy above and beyond expectations. I’ll definitely make sure I mention Aluminium Trade Supply to anyone I encounter looking for a fenestration solution 🙏🏼
15:13 13 Feb 23
We are looking to replace some old UPVC patios doors with aluminium ones. The ATS website is a great source of advice in an area where clear information is sorely lacking. Having used the website, I then followed this up with a number of specific questions relating to our search, and Nick came back very quickly with clear, detailed and very useful advice.I have been very impressed with both the website and with Nick's advice. My only regret is that I didn't come across ATS before replacing various windows in 2021 - I'm sure it would have saved me a lot of grief and money! Thanks again Nick.
Azza McCabeAzza McCabe
17:47 01 Feb 23
So impressed with this company.Responded to my query quickly andgave valuable advice. Nick was extremely helpful and we were able to move forward with our project.
Adri LoloçiAdri Loloçi
11:21 08 Jan 23
Nick was super fast to respond and provided some great recommendations. I would recommend this website to anyone looking to find bifold or sliding aluminium doors.
Stephen HoustonStephen Houston
16:16 03 Jan 23
Looking for aluminium crittall style internal door and external patio French doors. Noted good reviews and thought would ask for advice. Comprehensive reply with excellent independent advice and lists of fitters who could provide products and installation. Great service.
Inga GeachInga Geach
08:25 21 Dec 22
Nick from Aluminium Trade Supply has been extremely helpful with navigating the jungle that is aluminium glazing for our upcoming extension project. His advice was prompt, detailed and always impartial. Very grateful for your input, thanks Nick!
Amanda BurtonAmanda Burton
10:54 16 Dec 22
Brilliant website and an excellent service. Nick provided not only detailed advice and supplier contacts, but highlighted the considerations of various products so I could make an informed choice. Our Sunvista minimal sliders were fitted this week and I couldn't be happier, stunning. Thanks once again for your advice and recommendations, invaluable!
Keith BarnesKeith Barnes
17:18 10 Dec 22
Very helpful advice given to my question, including the name of 3 different companies that i could try for the product being enquired about. Many thanks
Munim ChowdhuryMunim Chowdhury
11:45 13 Sep 22
Nick has been very helpful on signposting me to a number of partner organisations for steel/aluminium doors.
SUSAN wallaceSUSAN wallace
17:26 31 Aug 22
My experience with this firm was exceptionally good and this is notalways the case as a female, dipping a toe into technical waters.I was spoken too with courtesy and at a level that helped me consolidate what was needed .On top of that I was given a list of companies and places where I could obtain the type of product I needed.I could not thank them enough and would certainly go there again and reccommend others do too.
Paul SalterPaul Salter
22:39 22 Aug 22
Contacting Aluminium Trade Supply is like contacting the Oracle direct. Advice is always comprehensive and balanced. On multiple occasions they have provided me with options that fully meet our objectives. Many thanks.
Nick McCormackNick McCormack
20:25 14 Aug 22
Really helpful and useful came back to me on a Sunday with some invaluable information. Highly recommended.
ray addisonray addison
13:14 14 Aug 22
received a prompt reply to my query,and helpful information from ATS