How Aluminium Windows Contribute to Passive House Designs

In Summary

• Aluminium windows with thermal breaks support the Passive House Standard by reducing heat loss and boosting energy efficiency
• Airtightness and slim frames allow for higher solar gains and better thermal insulation
• All Unique Glazing aluminium windows can be double or triple glazed to suit passive house components
• Our windows are made from recyclable aluminium, supporting the sustainability goals of the passive house movement
• Manufactured in-house, our windows offer high performance, fast lead times and bespoke design flexibility

As energy efficiency and sustainability become priorities for modern homeowners and architects, Passive House design is growing in popularity across the UK.

One of the most important components of these ultra-efficient homes is the window system—and aluminium windows are proving to be a smart, sustainable choice.

In this blog, we’ll explore how aluminium windows contribute to Passive House designs and why they’re a perfect fit for energy-conscious homes in London, Slough and beyond.

What is a Passive House (Passivhaus)?

A Passive House, also known as Passivhaus (the original German term), is a building designed to use minimal energy for heating and cooling. By focusing on exceptional thermal insulation, airtightness, and controlled ventilation with fresh air, Passive Houses significantly reduce energy usage and carbon emissions. Developed by the Passive House Institute (PHI) in Germany, this rigorous standard has gained international recognition for setting the benchmark in sustainable construction.

Whether you’re building from scratch or retrofitting an existing home, meeting Passive House certification involves choosing the right components – including high performance windows.

How aluminium windows support Passive House standards

To meet Passive House Standard requirements, every part of the building envelope must minimise heat transfer, air leakage and energy waste. That includes the windows, and here’s where our aluminium range excels.

Thermal performance that reduces heat loss

At Unique Glazing, our aluminium windows feature advanced polyamide thermal break technology, which creates a barrier between the internal and external frames. This dramatically slows the transfer of heat, helping to:

• Minimise heat loss
• Reduce reliance on central heating
• Maintain stable indoor temperatures

With U-values as low as 1.1W/m²K and A++ energy ratings, our aluminium windows are a great fit for energy-conscious homes aiming for the Passive House Standard.

Airtight designs for consistent comfort

Air leakage is one of the biggest obstacles to Passive House certification. That’s why all Unique Glazing aluminium windows are fitted with multi-point locking systems and precision-engineered seals to create a secure, airtight barrier.

Combined with triple glazing (where required), this keeps warmth inside during winter and unwanted draughts out – all while supporting healthy ventilation strategies built into the Passive House design.

Sustainability built into every frame

The passive house movement isn’t just about energy performance, it’s also about reducing environmental impact. Aluminium is one of the most sustainable window frame materials available:

• 100% recyclable and endlessly reusable
• Incredibly long lifespan (up to 45 years)
• Minimal maintenance required
• Resistant to corrosion, rot and UV damage

All the aluminium used in Unique Glazing products is sustainably sourced, making it a smart choice for eco-conscious building projects.

Other benefits of aluminium windows

Slim sightlines for maximum solar gains

Slimline aluminium frames mean more glass, less frame. This supports one of the core principles of Passive House design – using solar gains to naturally warm the home. The large glazing panes help capture free heat from the sun, while offering an uninterrupted connection to the outdoors.

Natural light intake that supports wellbeing

Natural light is key to comfortable, healthy homes. Our aluminium windows allow more daylight to flood in, helping reduce reliance on artificial lighting and improving overall mood and productivity indoors.

Exceptional durability with minimal maintenance

Unlike timber, aluminium doesn’t warp, crack or require frequent repainting. It’s also weather-resistant, standing up to the worst of British rain, wind and UV exposure. Maintenance is easy: a quick wipe-down with soapy water is all it takes to keep them looking pristine.

Aluminium windows from Unique Glazing

We manufacture and install aluminium windows throughout London, Slough and the South East. With bespoke sizing, custom colours, and both double and triple glazing options, our aluminium range is tailored to suit homes pursuing Passive House goals.

Aluminium casement windows

Popular for their ultraslim sightlines and wide-opening options, these windows combine style and strength. Ideal for capturing natural light and passive solar gain, they can be top or side hung and made to any size. Choose from colours like Anthracite Grey, Jet Black or textured woodgrain effects for a traditional touch.

Aluminium flush sash windows

With a sleek, seamless exterior, these windows are often selected for contemporary or heritage-style homes. Neatly closing into the frame for airtight performance, our flush sash designs are great for homeowners aiming for high thermal performance and minimalist aesthetics.

Frequently asked questions

What are passive house windows?

They are high performance windows with excellent thermal insulation and airtightness to meet Passive House energy standards.

Can aluminium windows be used in passive house designs?

Yes, especially those with thermal break technology, like our aluminium windows at Unique Glazing.

What U-value do passive house windows need?

Generally, below 0.8–1.0W/m²K. Our windows achieve as low as 1.1W/m²K and can be triple glazed for extra efficiency.

Are Unique Glazing aluminium windows certified?

While we don’t offer PHI-certified products, our windows meet and exceed UK Building Regulations and are manufactured to high performance standards.

What’s the difference between passivhaus windows and regular windows?

Passivhaus windows offer superior insulation, airtightness and solar control, contributing to ultra-low energy usage.

Who are Unique Glazing?

At Unique Glazing, we’ve been manufacturing and installing quality windows, doors and glazed extensions for over 20 years. As a family-run business, we care about getting things right—from product quality to customer service.

We work across London, Slough and the South East, offering bespoke products made in-house using premium materials. Our accreditations include:

• FENSA Approved Installers
• Liniar Approved Fabricators
• GGFi Insurance-backed Guarantees
• ICO registered for data protection

Our aluminium window styles include casement and flush sash, all available in a wide range of colours and finishes. We also offer energy-efficient uPVC windows, doors, orangeries and conservatories.

To learn more or get a free quote, contact us today on 0800 193 2425 or email sales@uniqueglazing.co.uk.