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Aluminium Windows

The Alitherm series of windows offer a range of high quality glazing solutions for side hung, top hung open out and parallel opening casements, suitable for both the residential and commercial markets.

This versatile range of profiles can provide many solutions such as traditional casement windows inspired by the elegance and styling of timber products, or automatic parallel opening commercial windows designed to provide a balanced airflow in multi-storey commercial buildings.

All Alitherm profiles utilise Smart’s innovative polyamide thermal break technology which creates a barrier between the cold air outside and the warm air inside. This technology significantly reduces thermal transmittance and enhances the overall U Value of a product.

Alitherm products are available in a choice of standard or non-standard colours, including metallic, dual colour and Smart’s unique Sensations range of textured finishes.

The series features the new Alitherm 300, Alitherm 600, Alitherm 700 and Alitherm 800 windows, designed to meet the exacting requirements of Document L 2010.

System Features:

  • Attractive, slim-line profiles offer reduced sightlines
  • Profiles available in either square or rounded edge options
  • Fabricated using mitred corners
  • Lock mechanism available with domestic style lift-up handle and an adjustable, one-piece keep
  • Low threshold option
  • Fully weather sealed

Aluminium Windows - More Details

Finish Single or dual colour, marine quality polyester powder coat as standard
Thermal Performance 1.8 W/mK
Air Test result pending
Wind Test result pending
Water Test result pending
Doc L 2010 Yes
Frame Depth 70mm
Typical sight line 132mm
Glass 28mm double or triple gazed units
Max o/a height (per sash) 2500mm
Max o/a width (per sash) 1000mm
Max sash weight 80kg

Aluminium Windows Example Pricing & Options

Aluminium Windows FAQ's

Aluminium Windows Energy Rating

Useful Information and Downloads


The Sliding Doors and Glass Walls Are Perfect

Review of Slimline Glazing & Aluminium Systems
Christine, Cornwall
5 out of 5

Fantastic Slimline Doors. When the plans were drawn up for the ultra contempory glass extensions to our 200 year old stone house I had a vision of how it would look and I am not disappointed. The SL18 doors and glass walls are perfect, as was dealing with the company and the team who successfully fitted the glazing on some of the coldest days of the year.

It looks absolutely stunning

Review of Slimline Glazing & Aluminium Systems
Abilgail - Chiswick, W4
5 out of 5

Hi guys - thanks for doing a great job on installing the roof lantern.. ! It looks absolutely stunning! W4 CHISWICK

Such a Dedicated, Efficient and Friendly Team

Review of Slimline Glazing & Aluminium Systems
Christine & Neils - Cornwall
5 out of 5

Thank you Abigail & Bob for sending such a dedicated, efficient and friendly team to fit the doors, they were great.

Simply fabulous!

Review of Slimline Glazing & Aluminium Systems
Rosie Taylor
5 out of 5

From start to finish Bob was helpful, knowledgeable and most importantly always available. Our job turned out to be more complicated than we anticipated but Bob found a way to resolve the issues and most importantly, satisfy our Building Control officer! Thank you for a wonderful end product!

SL20 Otimma Sliding Doors

Review of Slimline Glazing & Aluminium Systems
5 out of 5

We had 12mts of SL20 Otimma sliding doors installed and they look stunning! Best system on the market. We are equally impressed with the aftersales support as when one of the doors needed adjusting due to small movement of the new house they came within a day. Special thanks to Tony and Bob.

Compliments to the Fitters

Review of Slimline Glazing & Aluminium Systems
Ian, Surrey
5 out of 5

Great start today. Windows looking good so far. Brilliant workmanship. Compliments to the fitters for looking after the house so well and working so hard in the soaring heat! I cant wait to see the finished article.

Sliding Patio Doors

Review of Slimline Glazing & Aluminium Systems
N.L Oxford
4.5 out of 5

Dear Tony, The guys have just left. They did a great job of the sliding doors in all respects; they look terrific and I am really pleased with it.

Slimline Sliding Doors

Review of Slimline Glazing & Aluminium Systems
Nigel, SE7
4.5 out of 5

The guys finished the installation of the slimline sliding doors. It is a great product; I am pleased. The installation team were very pleasant and competent, with a good focus on quality and attention to detail.

Doors, Lantern and Window

Review of Slimline Glazing & Aluminium Systems
4 out of 5

Fantastic product. Delivered on everything they said they would. Makes the room look amazing...would highly recommend.

Very Pleased with the Fast and Efficient Service

Review of Slimline Glazing & Aluminium Systems
Becky, Surbiton
5 out of 5

I just wanted to say that I am very pleased with the service so far. I put in a query on Tuesday evening, had a conversation with Joanna Wednesday morning, had support from the installation team yesterday (Thursday) afternoon and placed the order at 4pm. Thank you so much for a fast and efficient service so far.

Simply Brilliant

Review of Slimline Glazing & Aluminium Systems
Karen Gallagher, London
5 out of 5

Your guys came yesterday and did a brilliant job finishing off. They were also very polite and tidy. We would like to say a big thank you to you for all your help and support - and going the extra mile to give us an amazingly professional service. You have been quite simply brilliant and we really appreciate it.

An Absolute Pleasure to Have Working in My Home

Review of Slimline Glazing & Aluminium Systems
Nick Evans, lONDON
5 out of 5

The windows are absolutely beautiful - but we appreciate this is importantly down to expert installation - please pass on a big thank you to all the installation teams. Each and every one - who have been outstanding craftsmen, highly professional in their approach and an absolute pleasure to have working in my home. We feel very fortunate to have found Slimline after our loft company builders had let us down on the architects specification for the windows

Everything as promised and the doors look amazing

Review of Slimline Glazing & Aluminium Systems
Mr Taylor
5 out of 5

I contacted slimline for sliding doors for my home. Its not easy getting to see them but slimline had a 6m set of sliding doors in their showroom. An excellent product and eight weeks after survey as promised ...they are in. Well done to everyone at Slimline. Highly reccommended

The walk on glass is amazing!

Review of Slimline Glazing & Aluminium Systems
Flora - Islington
5 out of 5

Many thanks for the work that was carried out at the house. By the way, the walk on glass is amazing! The guys have done a very good job!

Very helpful and did a good job

Review of Slimline Glazing & Aluminium Systems
Colin North - London
5 out of 5

To confirm that our French doors/windows unit was successfully installed today and we are very pleased with it. Your installation team were very helpful and did a good job making a very neat installation and finishing off the frame edges abutting the wall. We look forward to the installation of the glass balcony.

One less headache

Review of Slimline Glazing & Aluminium Systems
5 out of 5

Undergoing a full reconstruction and extension of our flat has been quite an undertaking and Tony Hall has taken what could easily be another headache and made it as fluid as I could imagine. Always contactable, it's like having your own project manager! Highly recommended.

A Great Glazing Range from Contemporary to Traditional

Review of Slimline Glazing & Aluminium Systems
MTA Architecture & Design
5 out of 5

We have specified glazing from Slimline on a number of our projects (including a recent extension in Knightsbridge, London). They have a great range of elegant products from contemporary to traditional.

Excellent Customer Service

Review of Slimline Glazing & Aluminium Systems
Berkeley Homes (South East Londonl) Ltd
5 out of 5

Just a short note, to say Thank you very much for consideration and efforts on past week. You really pushed the boat out on our meeting in the factory on Saturday, to touch and compare the doors. It’s had the desired affect and we shall move on now with Slimline Aluminium throughout. Again, thank you for your excellent customer service.

Great people to deal with

Review of Slimline Glazing & Aluminium Systems
Phil Hodgson
5 out of 5

Recently had a walk on glass roof fitted. Don't usually do reviews Slimline gave a good price and Bob in sales was a pleasure to deal with and discussed in a very informed way. Surveyor Tony very helpful and went out of his way and fitters also professional. Felt confident in job - will use again.


Review of Slimline Glazing & Aluminium Systems
Rob sykes
5 out of 5

We had a side extension built by Slimline glazing. Dan, the builder, was great and the work force very professional. I have to say the doors made the finishing touches - they are great. Great job all round.

Walk on Glass

Review of Slimline Glazing & Aluminium Systems
Mr Moorecroft, NW6
5 out of 5

I had some walk on glass fitted yesterday, which covered a big area. Slimline fitted all the steel work for installation prior to the glass. The finishing was great and they matched the mastic to the patio slab so it all blends in and looks great. We're really pleased.

Glass Extension

Review of Slimline Glazing & Aluminium Systems
Sarah Holmes - SW6
4.5 out of 5

We had a glass extension installed last week and it is great. Everyone was so helpful and the installers worked really hard. Everyone has commented on how it looks. Thanks!!

They Look Great !!!

Review of Slimline Glazing & Aluminium Systems
Peter Cummings - NW1 London
4 out of 5

We had 2 sets of the slim sliding patio doors and some walk on glass fitted just before Christmas. It was touch and go if it was going to be done before the festive season, but slimline glazing did really well and got our build water tight in time. We're really happy with the product and service. Well done to all.

We're really pleased

Review of Slimline Glazing & Aluminium Systems
5 out of 5

Thanks to everyone at slimline for being so professional and polite. They were always willing to help. We had a big set of sliding doors, 2 roof lights and a large glass roof fitted. They have really finished the build off thanks again. Mrs D Ingles, Eastbourne

Last Weeks Glass Installation

Review of Slimline Glazing & Aluminium Systems
Neil Marks
5 out of 5

I just want to say how pleased we are last Thursday the final piece to our puzzle was installed we have a property in West London and we were having a big glass roof fitted we had no access through the house so each piece of glass had to be craned over the house it looks fantastic!!

So pleased with the results

Review of Slimline Glazing & Aluminium Systems
Steve & Jane Wilmslow
5 out of 5

We were recommended by a friend at work to get a quotation for the glazing as we were having a fairly large extension and the back of our house re-built and modernised. Everything was going great until our builder went bust and left us in a dilemma. Tony at the Slimline office helped us obtain a new builder and Slimline then took over the remainder of the construction works - installing their doors and windows. It took a little longer due to the hiccups we had but we are so pleased and grateful for the results.

Project in Battersea

Review of Slimline Glazing & Aluminium Systems
Greg Hastings
4.5 out of 5

I commissioned Slimline Aluminium to provide a glazing package for our project in Battersea. We had sliding doors, balustrades, an electric roof light, plus some additional windows and doors. Slimline worked well with our contractor and deliverd on time - great job!

Walk on Glass project

Review of Slimline Glazing & Aluminium Systems
Robin Walker. SW1
5 out of 5

I used Slimline for a Walk on Glass project in central London. The quality of the works is second to none and I was informed all the way through the project. I was very happy and so was my customer. I’ve since used slimline glazing on a project that involved a very complex structural glass extension. They provided all the right help from the glass and structural engineers and all drawings were designed correctly - which made the installation process a lot easier, really happy!!

3 panel sliding doors

Review of Slimline Glazing & Aluminium Systems
Mr Mikal - Ealing
4.5 out of 5

We had a 3 door set of Slimline's sliding doors installed at our property in Ealing 2 months ago. They are so easy to slide and the middle sections are so narrow. it’s great when the doors are shut as there are no thick frames that obstruct the view. We have recommended at least 3 people so far. I must say, our friends do not stop commenting on them.

Roof lanterns

Review of Slimline Glazing & Aluminium Systems
Café Italia
4.5 out of 5

Slimline Glazing installed a Slimline roof lantern for us at our restaurant when we had the refurb done, everyone one who walks in asks us were we got it from it really sets off the area were we had the work done it lets in so much light they weren’t the cheapest but the quality was second to none but everyone was so polite from start to finish and met all our requirements.

Thank you Slimline Glazing

Review of Slimline Glazing & Aluminium Systems
Jane - Surrey
4.5 out of 5

I've just had a new set of SL17 sliding doors installed by Tony and his team. What a great job. The doors have transformed my old gloomy kitchen into a bright space that's enjoyable to use again.

sl600 aluminium door

Review of Slimline Glazing & Aluminium Systems
P.T Manchester
4.5 out of 5

Although we initially wanted the sl17 doors (which are amazing but a little out of our price bracket), we opted for the sl600 in the end - which were still expensive but did fit in to our budget. We are so please with them. They're great modern door and really don't feel like a compromise. we would (and have) recommend Slimline and their doors to anyone.

Blog Posts

Case Study: Full Width Rear Extension
Posted on 05/11/2017 in Case Study

Built originally as a ‘show home’ for the development of a group of two-to-three-storey detached and semi-detached family homes, this property is located at the edge of a typical suburban residential development in Borehamwood erected in the 2000s. The property was originally designed with a standard square configuration.

read full article

The Technical Aspects of Glass
Posted on 18/01/2017 in Property

Glass is just glass, right? It’s a part of your home that you probably take for granted. It lets you see outside, it allows the light in, and without it your world would be a whole lot darker!

read full article

Eight Seasonal (and not so seasonal) Ways to Spend Christmas Day
Posted on 16/12/2016 in Property

Christmas is finally upon us, and it’s the season to be jolly. For most, it’s a time to enjoy relaxing with your family, indulging in the finer things in life, and being thankful for your array of gifts.

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Dear Santa... Please Use The Door
Posted on 08/12/2016 in Doors

Stop for a moment and consider one of the most important factors of Christmas - just how does Santa get into your home to deliver all your presents? Rumour has it he uses the chimney, but here at Slimline Glazing we know different...

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13 facts You Didn’t Know About Doors
Posted on 30/11/2016 in Doors

To show you what an impact they have on your life, we’ve rounded up our favourite facts and figures about the humble door – you’ll never take your door for granted again!

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Improve Your Property’s Value with Quality Glazing
Posted on 09/08/2016 in Doors

You’ve probably heard it before – investing in quality glazing can improve the value of your home. It’s a double glazing salesman’s mantra, designed to make you instantly open your wallet, and re-vamp every window in your home.

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What Are The Right Aluminium Windows For You?
Posted on 22/07/2016 in Windows

You would think that a window was just a window – something to admire the view out of, something to open to let some air in, and something extra to clean on a regular basis! But think again, because with a little bit of thought you can use windows to add an extra dimension to your home. Whether you are looking to maintain the character of your home or completely change the perspective, your choice of window can have a big impact.

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Slimline Glazing Wins the 2016 Sustainable Building Awards
Posted on 04/07/2016 in Doors

We are very happy to announce that Slimline Glazing and Aluminium Systems have won the 2016 Sustainable Building Awards - London. Which not only is a very proud moment for all at Slimline Glazing, but it also strengthens our message about how eco-friendly aluminium doors and windows are.

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5 Reasons Aluminium Glazing is a Long Term Investment
Posted on 21/06/2016 in Doors

Here at Slimline we sell aluminium glazing products. So just why do we sell aluminium instead of uPVC, timber, vinyl or other materials? The reason – because aluminium offers our customers a much better long term investment than these other products, as well as being a top quality and versatile material.

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Slimline Have Been Nominated for the 2016 Sustainable Building Awards
Posted on 08/06/2016 in Doors

We’ve just been nominated for the 2016 Sustainable Building Awards, which not only is a very proud moment for all at Slimline Glazing, but it also strengthens our message about how eco-friendly aluminium doors and windows are.

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The Benefits of Sliding Glass Doors
Posted on 24/05/2016 in Doors

If, like me, you’ve lived with French patio doors that open inwards, you will appreciate how inconvenient they can be.

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Bring Elegance to your Home with Luxury Sliding Doors
Posted on 16/05/2016 in Doors

When is a patio door more than just a patio door? Answer: - when it transforms your home from the ordinary to the elegant.

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Using Glass Doors to Light Up Your Home
Posted on 10/05/2016 in Property

Having a north facing living room can be a bit of an inconvenience. Whatever time of day or year, odds are on that you have a lamp on in one of the corners. When it comes to cleaning, those dark areas are often skimmed over, as you close your eyes to the spiders that love the doom and gloom of that hidden hideaway.

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Bring in the Spring with Folding Glass Doors
Posted on 27/04/2016 in Property

There’s definitely a new kid on the block and it’s growing in popularity. Gone are the days of traditional French windows opening onto your patio; now it’s the time of folding doors to take the throne and rule!

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Open Up Your Home with Electric Sliding Roof Lights
Posted on 22/03/2016 in Property

Imagine – it’s a beautiful evening and you’re dining under the stars. There’s a soft breeze drifting around you, making you feel at one with nature. Then suddenly, an ominous cloud looms out of nowhere, and you feel the promise of rain in the air. Yet before the storm settles in, you’re closeted against the weather, enjoying your supper undisturbed. All without even having to touch a button.

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Aluminium Frames vs Wooden vs UPVC
Posted on 07/03/2016 in Doors

There’s a raging debate going on right now in the glazing industry; which material is best for patio doors and window frames? Advocates of wood, uPVC and aluminium get quite heated about their favourite!

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Case Study: Glazing a modern 'Tailored House' in Kensington and Chelsea
Posted on 18/01/2016 in Case Study

Although technically a new build, there was previously a house at the end of this Victorian terrace in Kensington and Chelsea. However, it was destroyed by bombs in World War Two. The house is in the centre of the Brook Green conservation area - located close to Kensington Olympia, Hammersmith Broadway and Shepherds Bush.

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Case Study: Modernising a Victorian Mews House in Kensington with Bespoke Glazing
Posted on 05/01/2016 in Case Study

This Victorian Mews home was built in the 1870’s, and has kept many of the original features. It is full of character, and the Mews itself is well known as the home of the famous painter of the 1900’s, Francis Bacon

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5 out of 5
Slimline Glazing & Aluminium Systems.
Rated 5 out of 5 based on 32 user reviews.

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