Trusted Heritage Windows for Conservation and Trade Projects
Aluminium Heritage Windows Designed for Conservation Compliance and Trade Confidence
When specifying windows for conservation zones or heritage-style builds, precision matters. The Alitherm Heritage aluminium range delivers the authentic sightlines, elegant proportions and glazing flexibility required for planning consent – all while meeting modern performance standards.
At Mercury Glazing, we don’t buy in and re-sell: we manufacture Alitherm Heritage aluminium windows in-house at our UK facility. That means total control over quality, design, lead times, and service – backed by expert support for trade professionals. With turnaround times under four weeks, we’re the partner installers rely on to keep heritage projects moving.
Whether you’re restoring a listed building or creating period-style extensions in conservation areas, our heritage window systems combine timeless looks with today’s performance standards.
What Are Heritage Windows – and Why Do They Matter in 2025?
Heritage windows are designed to replicate the traditional features of period fenestration – from slender frames and putty-like detailing to flush joints and accurate glazing bars. They’re often required in conservation areas, listed buildings, or anywhere planners expect visual continuity with original architecture.
In 2025, energy standards and retrofit regulations have made heritage compliance more complex. Specifiers now need to balance visual authenticity with thermal efficiency and security – all while staying within the strict limits of conservation planning.
That’s why solutions like Alitherm Heritage are in high demand. They allow for modern aluminium performance – such as thermally broken frames and secure multipoint locking – in a form that’s virtually indistinguishable from steel or timber originals. Historic England confirms that well-designed upgrades can reduce heat loss without compromising historic value – as long as proportions and sightlines are respected.
Conservation Area Ready: The Case for Alitherm Heritage Aluminium
Alitherm Heritage windows have been developed specifically for use in period-sensitive settings. Their slimline aluminium construction closely mimics the proportions of traditional steel and timber windows, making them ideal for sensitive refurbishments and conservation area approvals.
In cities like Bristol, planning permission for conservation areas requires care when upgrading fenestration. Visual impact is assessed alongside performance, meaning installers must choose systems that offer both.
“When planning rules are tight, performance can’t come at the expense of design. That’s where Alitherm Heritage delivers – and we manufacture it in-house to exact spec,” says Steven Cross, Director at Mercury Glazing.
By combining heritage-accurate detailing with modern compliance, Alitherm Heritage has become a preferred choice for contractors navigating conservation constraints.
For Trade: Manufactured in Britain, Supported by Experts
Trade professionals know that sourcing matters – and working with a true UK manufacturer like Mercury Glazing can make all the difference. Unlike suppliers who drop-ship or import finished frames, we fabricate every Alitherm Heritage window in-house, ensuring consistent quality, faster lead times, and expert control over the final product.
We work directly with installers, contractors, architects and specifiers to ensure each heritage window project is delivered to spec – and on time. Whether you’re managing a multi-property retrofit or a single bespoke restoration, we offer:
- Detailed technical drawings and specification advice
- Accurate quoting with fast turnaround
- Advice on conservation zone planning considerations
- Product samples, colour options and glazing configurations
With our standard lead time of under four weeks, Mercury Glazing is the reliable partner that trade professionals trust for heritage aluminium windows. We don’t move on or drop out – we stay involved, offering support from quote to completion. That’s the benefit of working with a manufacturer, not just a seller.
Explore our dedicated heritage aluminium windows for trade page to see how we support your next project.
What Installers and Contractors Gain from a True UK Manufacturer
Choosing a UK manufacturer isn’t just about geography – it’s about peace of mind. Mercury Glazing offers trade partners direct access to the people who design, build, and test the windows themselves. There’s no middleman, no confusion, and no surprises.
We understand the challenges contractors face, from planning delays and delivery hold-ups to incorrect specifications and hard-to-reach support. That’s why we’ve built our process around what installers need most:
- Precise product knowledge from the first conversation
- Configurations tailored to your build method
- Support with conservation-friendly options and approvals
- Shorter lead times without compromising quality
Buying from a distributor may seem quicker – until the spec changes or something’s missing. Working with Mercury Glazing means fewer site delays, more accurate installations, and a stronger reputation with your client.
Our in-house manufacturing also means better quality control and long-term consistency – especially when working on phased heritage refurbishments or larger housing projects.
To see how our aluminium heritage windows align with homeowner expectations, visit our homeowner Alitherm Heritage range.
Planning Permission in Conservation Areas: What to Know in 2025
Getting planning consent in a conservation area requires more than just high-quality windows – it requires windows that look right, perform well, and respect the character of the building.
Mercury’s Alitherm Heritage windows are designed with conservation in mind. They replicate the key visual features expected by planning officers:
- Narrow sightlines
- Traditional framing proportions
- Optional glazing bars and horizontal rail options
- Colour-matched powder-coated finishes
These design elements help meet local planning authority expectations for heritage-sensitive projects. In many cases, including across Bristol’s conservation areas, this level of visual compatibility is essential for fast-track approval.
Our team understands the technical and visual requirements involved and can help advise on configurations that balance energy efficiency with aesthetic integrity – all within current 2025 planning frameworks.
Why Alitherm Heritage Wins on Both Aesthetics and Performance
Heritage window projects used to force a choice: historic accuracy or modern performance. With the Alitherm Heritage system, there’s no need to compromise. This advanced aluminium profile combines ultra-slim styling with the thermal and security standards demanded by today’s building regulations.
Each frame is thermally broken to reduce heat transfer and achieve excellent U-values. Compatible with both double and single glazing, it offers flexibility depending on conservation requirements and project scope. The system also meets PAS 24 standards for security when required.
Visually, Alitherm Heritage recreates the look of original steel or timber windows through:
- Ovolo detailing
- Stepped sashes
- Authentic transom alignment
- Heritage-style handles and stays
That makes it ideal for listed buildings, barn conversions, and character-led refurbishments where maintaining external appearance is essential – especially when aligned with retrofit energy-saving measures supported by Historic England.
It’s this balance of appearance, energy performance and durability that sets Alitherm Heritage apart in the trade market.
“We’ve seen a real increase in demand from trade customers working on conservation-led projects who are tired of delays and mismatched deliveries. Because we manufacture everything in-house, we can get Alitherm Heritage windows out quickly – and right first time.” – Andy Miller, Head of Sales, Mercury Glazing
Faster Turnaround Without Compromising Quality
Lead times can make or break a heritage window project. Mercury Glazing offers under four-week turnaround on Alitherm Heritage aluminium windows – without cutting corners.
Our streamlined in-house manufacturing allows for:
- Faster start-to-site delivery
- Tighter quality control
- Real-time updates on production and availability
- Swift resolution of spec changes
This flexibility is especially valuable when dealing with sensitive planning deadlines or phasing constraints on multi-unit refurbishments.
Because everything is built under one roof, we don’t rely on offshore imports, third-party factories, or untracked shipping delays. You get what you’ve ordered – when you need it – from a team that understands your project.
For more on our heritage window supply process, visit the dedicated trade page.
Cliff House, Felixstowe
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Foxhill House, Chester
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University of Sussex, Brighton
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Varndean College, Brighton
VIEW PROJECTFrom sash windows to aluminium bifold doors, our high-quality products are engineered and manufactured right here in Britain. We work with fellow UK-operated companies, Spectus Window Systems, Smart Systems, and Jack Aluminium Systems, to deliver only the very best to our trade, commercial and residential customers.
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