U-Values from 0.8
Whole window U-values as low as 0.8 W/m2K with high performance insulating glass, exceeding Part L.
- Crittall Steel
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Crittall® T60 Steel Windows
T60 is a thermally broken steel window and door system, developed as a viable alternative to the traditional hot rolled steel window for projects that have to meet modern energy targets. A high density polyurethane GRP thermal isolator runs through the profile, interrupting the path heat takes through the frame. That single change is what separates T60 from the rest of the range. Fitted with high performance insulating glass, T60 achieves whole window U-values as low as 0.8 W/m2K, against around 1.4 W/m2K for Corporate W20 TE. Sound reduction of over 40dB is achievable with laminated acoustic glass. The system is double weatherstripped and double glazed as standard, with triple glazing available. Lightfoot Windows supply and install T60 across London, the South East and the Channel Islands, managing specification, survey, manufacture and installation.
T60 Window Benefits
The features that make T60 the most thermally capable system in the Crittall steel window range.
Over 40dB Sound Reduction
Sound reduction of more than 40dB is achievable where laminated acoustic glass is specified.
Traditional Sightlines
Visually almost identical to Crittall's traditional rolled steel profiles, with slim sightlines retained.
Tested to EN16727
Conforms to security standard EN16727, with multi point locking available as an option.
What Is the Crittall T60 Window Range
T60 is Crittall’s thermally broken steel window and door system, developed as a viable alternative to the traditional hot rolled steel window for all project types. It replicates the look of a classic Crittall window while incorporating an integral thermal isolator, allowing it to meet contemporary energy requirements in buildings where traditional steel fenestration would previously have struggled.
How the Thermal Break Works
The profiles carry integral polyurethane GRP thermal isolators with 67 per cent fibreglass content, tested in accordance with EN 14024. The isolator sits between the inner and outer steel sections and interrupts the conductive path through the frame, which is what lifts whole window performance to as low as 0.8 W/m2K. Because the break is internal to the profile, the sightlines stay slim and the window still reads as steel from either side.
T60 or Corporate W20TE
Both systems improve on the thermal performance of traditional rolled steel, but they do it differently and they suit different briefs. T60 is fully thermally broken and reaches as low as 0.8 W/m2K, making it the choice where energy performance drives the specification. Corporate W20TE achieves around 1.4 W/m2K and holds closer to the original heritage profile, which matters where conservation consent is in play. We will tell you which applies to your openings before you commit.
Configurations and Maximum Sizes
The range includes fixed lights, top hung, projecting top hung, side hung, bottom hung and french casement configurations, opening in or out, with internally glazed options available. Shaped windows including arches and rakes are manufactured within the system, although raked heads are available on windows only and not on top hung units. Fixed lights run to a maximum of 2750mm by 2750mm with a perimeter of 8800mm. Projected top hung units run to 1829mm by 1118mm, perimeter 4758mm.
Finish and Corrosion Protection
T60 uses a galvannealed zinc iron ZF100 coated steel substrate at approximately 100g per square metre. The substrate is chemically cleaned and pre treated, then zinc primed and finished in Duralife D2525 polyester powder coating applied in accordance with BS EN ISO 13438, at a minimum of 60 micrometres per coat on all significant surfaces. Every frame is fully welded. Note that this differs from the hot dip galvanising used on Corporate W20 and MW40.
Supplied and Installed by Lightfoot Windows Since 1935
As a Crittall Specialist Partner with decades of experience, Lightfoot Windows manages every stage of a T60 project, from initial specification and site survey through to manufacture and installation. Our team works with architects, specifiers and homeowners across London, the South East and the Channel Islands, including new build, extension and heritage renovation work requiring Part L compliance.
Crittall T60 Windows Gallery
Browse a selection of T60 installations, supplied and fitted by Lightfoot Windows across new build, extension and heritage projects.
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Configured to Suit Your Project
T60 pairs the appearance of traditional steel fenestration with the thermal and acoustic performance modern buildings are required to deliver. Colour, hardware, specification and frame options are set out below.- Popular Colours
- Hardware
Popular Colours
Colour and Finish Options
T60 frames are finished in Duralife polyester powder coating, applied over a galvannealed zinc iron substrate to BS EN ISO 13438 at a minimum of 60 micrometres per coat. Any RAL or BS colour is available, or we can match a bespoke reference. Black remains the most requested finish on residential projects, with anthracite grey and off white common on new build elevations.
Pastel Green
White
Light Grey
Agate Grey
Traffic Grey
Black
Hardware
Hardware for T60 Windows
T60 hardware is available in two ranges. The Classic Collection follows traditional Crittall patterns for period restorations, while the Luxury Collection offers contemporary handles and stays for modern elevations. T60 conforms to security standard EN16727, with multi point locking available where security governs the specification. Because the hardware is standard across the range, replacement parts stay available for the life of the window.
Soho Casement Handle
Phoenix Casement Handle
Deco Casement Handle
Berkeley Casement Handle
Arched Casement Handle
Straight Casement Handle
Scroll Casement Handle
Curved Casement Handle
Sliding Stay with Round Knob
Straight Peg Stay
Curved Peg Stay
Sliding Stay with Butterfly
Latest Projects
T60 at a Glance
The specification points that matter most when you are comparing T60 against the rest of the Crittall steel window range.- Whole window U-values from 0.8 W/m2K
- Integral polyurethane GRP thermal isolators
- Over 40dB sound reduction achievable
- Double glazed as standard, triple glazing optional
- Double weatherstripped, fully welded frames
- 60mm frame depth with slim sightlines
- Conforms to security standard EN16727
- Multi point locking available
- Shaped arches and rakes available
- Matching T60 doors within the range
Crittall T60 Windows FAQs
Here are answers to the questions we are asked most often about the T60 range, to help you specify with confidence.
What U-value do Crittall T60 windows achieve?
T60 achieves whole window U-values as low as 0.8 W/m2K when fitted with high performance insulating glass, which exceeds current Part L requirements. The figure achieved on your project depends on unit size, glazing build up and opening type, and is confirmed at specification stage.
What is the difference between T60 and W20 TE windows?
T60 is fully thermally broken, using an integral polyurethane GRP isolator, and reaches as low as 0.8 W/m2K. Corporate W20 TE achieves around 1.4 W/m2K and stays closer to the traditional heritage profile. Choose T60 where energy performance drives the brief, W20 TE where conservation consent does.
Are Crittall T60 windows double or triple glazed?
T60 is double weatherstripped and double glazed as standard, with triple glazing available as an option. The thermal isolator is what allows the system to accommodate high performance glazing while keeping the frame slim.
How much sound reduction do T60 windows provide?
Sound reduction of over 40dB is achievable where laminated acoustic glass is specified. That makes T60 worth considering on elevations facing busy roads, railway lines or flight paths, where the acoustic requirement is as important as the thermal one.
Are T60 windows suitable for listed buildings?
Sometimes, but not always. T60 replicates the look of traditional rolled steel closely, and shaped frames including arches and rakes are available. Where consent requires single glazing or an exact historic profile, Corporate W20 is usually the more appropriate system. We advise on this before you submit an application.
Are matching T60 doors available?
Yes. Matching doors are manufactured within the T60 range, so a door and window set on the same elevation reads as one system with consistent sightlines and the same thermal performance.
Explore Our Full Range of Crittall Steel Windows
T60 is one of several Crittall steel window systems we supply. Discover the full range, including Corporate W20, W20 TE, MW40 and Homelight, and find the right system for your project.
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What our customers say
Despite being a small project by comparison, from start to finish our project has been executed with precision, promptness and professionalism to deliver a thing if beauty which as we...
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Sharman & Phil
LOVE. LOVE. LOVE my windows and doors! They look amazing! ? Lightfoot Windows were a pleasure to deal with. Polite, helpful and informative. Plan to use them again for a...
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Adiba Ghauri
Very efficient and thorough. Quick installation. Very helpful and friendly staff. My new Crittall windows are beautiful.
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Susan Tuffy
I would like to thank the team at Lightfoot windows for supplying and fitting my new Crittal windows, from start to finish the service has been great and the product...
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Lee
Excellent windows (Heritage Aluminium french doors). Our builder was impressed with the excellent quality and will be using again. Efficient fitting, fitted perfectly.
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Sophia Barlow
I am very pleased with the Crittall windows as supplied and fitted by Lightfoot. I visited their showroom and discussed the requirements, and these were met in full. From the...
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David SC
Probably one the best experiences we've had with a building contractor/supplier. We went to the showroom where we were given all the information we needed and shown the various options...
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Paul Phillips
Lightfoot supplied & installed a steel Crittal arch for an internal opening. Both the design and install process was very professional and we are delighted with the product. Would highly...
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Richard Simpson
We have used Lightfoot Windows on two occasions now, and both times their service has been exemplary. The products we purchased are also of a very high quality and we...
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Martin French
I cannot recommend Lightfoot highly enough. I used to run a business, and the sheer pleasure and relief of being communicated with properly and courteously means a lot. It’s rare...
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Catherine C
So happy to have found Lightfoot Windows who supplied fire rated Crittall doors and screens. Great showroom full of inspiration. Unhurried great advice given, quote and contract really streamlined and...
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Torsten Mansson
Despite being a small project by comparison, from start to finish our project has been executed with precision, promptness and professionalism to deliver a thing if beauty which as we had hoped brings the outside in - our garden by day and the stars by night. We had the pleasure of Reese (still amazed at the price of a cup of tea and a bed for the night in Driffield) and Brad installing our curtain wall, accounting for the vagaries of an old property on a freezing cold day. Marcin as surveyor/project managing was careful and considered in his surveying and measuring. Clear and concise in his instructions to our builder. Paul's input at the design and acquisition stage ensured there was accurate representation of what we wanted. Praise indeed from an aircraft design engineer used to working to a "thou of an inch". We wouldn't hesitate to recommend investing in this company and its products.
Sharman & Phil
LOVE. LOVE. LOVE my windows and doors! They look amazing! ? Lightfoot Windows were a pleasure to deal with. Polite, helpful and informative. Plan to use them again for a new internal window very soon. Would definitely recommend. Thank you guys !
Adiba Ghauri
Very efficient and thorough. Quick installation. Very helpful and friendly staff. My new Crittall windows are beautiful.
Susan Tuffy
I would like to thank the team at Lightfoot windows for supplying and fitting my new Crittal windows, from start to finish the service has been great and the product is first class. great value for money.
Lee
Excellent windows (Heritage Aluminium french doors). Our builder was impressed with the excellent quality and will be using again. Efficient fitting, fitted perfectly.
Sophia Barlow
I am very pleased with the Crittall windows as supplied and fitted by Lightfoot. I visited their showroom and discussed the requirements, and these were met in full. From the initial visit to the final fitting Lightfoot exceeded my expectations and I would unhesitatingly recommend them.
David SC
Probably one the best experiences we've had with a building contractor/supplier. We went to the showroom where we were given all the information we needed and shown the various options for our kitchen patio doors. We selected what we wanted and gave the dimensions and by the time we got home, there was a plan and an estimate in our inbox.
Paul Phillips
Lightfoot supplied & installed a steel Crittal arch for an internal opening. Both the design and install process was very professional and we are delighted with the product. Would highly recommend and I would certainly use them again for future products.
Richard Simpson
We have used Lightfoot Windows on two occasions now, and both times their service has been exemplary. The products we purchased are also of a very high quality and we are really happy with them. The surveyors and installers were careful, considerate and polite. We highly recommend Lightfoot Windows and will definitely use them again should the need arise.
Martin French
I cannot recommend Lightfoot highly enough. I used to run a business, and the sheer pleasure and relief of being communicated with properly and courteously means a lot. It’s rare these days. The windows and installation were excellent. Reece, Grant & Bradley were fantastic. Particularly as they were up against supply issues, parking restrictions not to mention Covid.
Catherine C
So happy to have found Lightfoot Windows who supplied fire rated Crittall doors and screens. Great showroom full of inspiration. Unhurried great advice given, quote and contract really streamlined and easy to understand. Service was excellent throughout visiting, ordering measuring up and installation. Special thanks to Daniel at the showroom, Reece Taylor for an excellent installation and finish. Really pleased with the product and service. Would not hesitate to recommend and will definitely use again in the future.
Torsten Mansson