10 Year Guarantee
Available on all products
Energy Saving Products
A+ rated window & doors
Competitive Prices
Value for money
Qualified Team
Strict industry standards
Smart Alitherm Heritage System Benefits
- Lightweight material, yet extremely strong and durable
- Slim profiles and sightlines, allowing for more glazing which leads to an increased amount of natural light
- 100% recyclable
- Great way to modernise any home
- Designed as a direct replacement for steel windows
- Polyamide thermal break provides enhanced thermal performance
- High security, with a multi-point locking system
- Low maintenance
Technical Performance and Compliance of Heritage Slimline Aluminium Windows
Our heritage windows comply with listed building regulations and British standards, offering high-performance glazing solutions. The Smart Alitherm Heritage system features multi-chamber sections that enhance insulation, achieving U-values as low as 1.4 W/m²K. Combined with advanced weather seals, these heritage slimline windows prevent drafts and condensation.
Our aluminium window replacement options meet PAS 24 security criteria and include robust multi-point locking systems for enhanced protection. Independently tested to guarantee performance levels, these windows ensure period property windows remain secure, weatherproof, and compliant with conservation requirements.
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Customisation for Period Property Windows
Our heritage aluminium windows are fully customisable to suit the architectural style of period property windows. Choose from a comprehensive RAL colour palette to match historic ironmongery and surrounding brickwork. We offer a variety of glazing options—such as slim-line double glazing or slim triple glazing—to meet your energy efficiency requirements while maintaining authentic sightlines. Heritage hardware selections, including reproduction handles, stay bars, and peg stays, ensure every detail reflects original steel window charm.
For homeowners in Aylesbury and beyond, our design team provides expert guidance from initial consultation to final installation, ensuring every detail—from frame profile to finish—is tailored to each project.
Contact UsSecurity Features for Added Peace of Mind
Security is paramount in historic properties, which is why our heritage slimline windows incorporate state-of-the-art protection. All units feature PAS 24 security certification and high-security locking points integrated into the frame. The multi-point locking systems secure the window sash at multiple locations, deterring forced entry while maintaining slimline profiles.
With reinforced aluminium sections and steel-reinforced stiles, our heritage aluminium windows provide the strength of steel while benefiting from aluminium’s low maintenance properties, giving homeowners confidence in their steel window replacement choice.
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Local Expertise and Installation
As Buckinghamshire heritage window experts, our professional installation teams are accredited and experienced in working on conservation areas. We collaborate with local councils and conservation officers to ensure all installations respect period property windows and preserve architectural integrity.
Our commitment to quality craftsmanship and attention to detail makes us the leading provider of heritage windows Aylesbury & surrounding areas residents trust.
Get A QuoteTransform Your Period Home Today
Experience the best of both worlds with Double Glazing Direct’s heritage slimline windows—time-honoured aesthetics combined with modern thermal break technology and security. Contact our Aylesbury showroom to arrange a consultation with our knowledgeable team.
Let us guide you through selecting the ideal heritage aluminium windows for your Buckinghamshire or surrounding areas home, ensuring authenticity, performance, and lasting value.
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Colours
Whether your home improvement project requires bright white aluminium windows, modern black aluminium windows or something more vibrant, finding the best fit for your project is incredibly straightforward with a Double Glazing Direct installation.
The Heritage range is available in a choice of single or dual colour options to give you the ultimate, stylish finish.
Glass Options
Thanks to an ultra-insulating polyamide 'thermal break' element, Heritage windows are energy efficient and are capable of achieving A Window Energy Ratings with modern double glazing & Building Regulation compliant U-values with advanced triple glazing. If your room suffers from overheating in summer or is too cold to use in winter, we can install temperature-moderating Low-E glass. We also have an attractive range of decorative glazing, perfect for intricate heritage projects, adding privacy, and one-of-a-kind installations.
Cassini
Warwick
Taffeta
Tribal
Reeded
Pelerine
Accessories
From chrome inline locking window handles to exquisite Monkey Tail handles and teardrop dummy window stay bars that hark back to a simpler time - as well as heritage-inspired Georgian bar, Astragal bar, and mock sash horn detailing options - we're confident we have the perfect finishing touch for your new Heritage windows to truly make them your own.
Security
These Heritage aluminium slimline windows offer inbuilt security with a multi-point locking system.
As well as the option to add an extra layer of protection with advanced triple glazing and high quality window locks as standard, all Heritage products from Smart undergo extensive testing and checks. This means they can achieve the sought-after PAS 24: 2016 Enhanced Security Performance status, for peace of mind they can resist physical attacks by opportunist burglars.
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What do our customers say?
See more reviewsVery quick and professional service
I am very impressed, my home is much improved. Very professional. Prompt. Punctual. I highly recommend. THANK YOU ALL. I have just been in contact with Double Glazing Direct regarding...
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Damien Martin
We will be going back to Double Glazing Direct
Double Glazing Direct changed our very old and leaky polycarbonate conservatory roof to a new solid roof as well as changing the windows and doors of the same area. From...
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Buckinghamshire
‘Double Glazing Direct’ were brilliant.
They were extremely polite and professional. Before they started the work on the day of installation, taking out the existing windows, they prepared the area with dust sheets and special...
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Greater London
Great job, professional service
Replaced an old aluminium frame patio door with updated upvc doors. Work undertaken very professionally, leaving the area clean and tidy afterwards. Noticed a very slight imperfection upon completion but...
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Buckinghamshire
I would highly recommend
Marc and his team did an excellent job of replacing our conservatory glass roof with a Guardian Warm Roof. Work started on time and was completed within the stated time...
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David Tomlinson
Outstanding Service
We had many issues trying to locate a company to replace our conservatory roof however, this company was recommended to us by a friend of a friend and we couldn’t...
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Buckinghamshire
Visit our double glazing showroom in Aylesbury
We understand that improving your property is a big step, and it can often be difficult to picture new windows, doors and more by just looking at an image on a screen.
Our superb showroom in Aylesbury is the perfect place to get a real feel for the quality of our products and chat with a member of our team to learn more about transforming your home or business.
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Get an Online Quote
Getting a quote on your next property improvement couldn't be easier! Simply enter your details and one of our team will be in touch shortly with a comprehensive price for the work.