Passivhaus Windows

Passivhaus windows are high-performance window systems built to cut heat loss, seal out draughts and hold stable, comfortable temperatures inside low-energy commercial buildings. To qualify, a window has to perform as a complete unit with glazing, frame, spacer, seals and installed junctions working together.

TECHNAL's SOLEAL Next 75 is certified by the Passive House Institute (efficiency class phC, cool-temperate climate) with a certified whole-window U-value of 0.79 W/(m²K).

For architects, developers, façade consultants, specifiers and fabricators across the UK and Ireland, that means a commercial aluminium window system you can specify against genuine Passivhaus targets.

Discuss Passivhaus window specification with TECHNAL.

What Are Passivhaus Windows?

Passivhaus windows are high-performance windows designed to support the demanding energy efficiency requirements of Passivhaus and Passivhaus-aligned buildings. Rather than relying on a single component, their performance depends on how the entire window system works together to reduce heat loss, maximise thermal efficiency and maintain a comfortable indoor environment.

A Passivhaus window typically combines:

• High-performance glazing.

• An insulated frame.

• Warm-edge spacers.

• Excellent airtightness.

• Carefully designed thermal breaks.

However, even the most advanced passive house windows can underperform if installation details allow thermal bridging or air leakage around the building envelope. Whole-window performance and the quality of installation are therefore just as important as the specification of the glazing itself.

For commercial projects, selecting a passive house window should form part of a wider building envelope strategy that considers façade performance, ventilation, solar control and long-term operational efficiency.

Key Passivhaus Window Performance Requirements

When evaluating passive house window systems, specifiers should consider the complete performance of the installed window rather than focusing on individual product characteristics.

Key criteria include:

• Whole-window U-value (Uw) ≤ 0.80 W/(m²K): the headline Passivhaus requirement. SOLEAL Next 75 achieves a certified 0.79 W/(m²K).

• Glazing: typically triple glazing with low-emissivity coatings and argon or krypton fill. SOLEAL Next 75 is certified with a 48 mm triple-glazed build-up (4/18/4/18/4).

• g-value: a solar heat gain balanced to contribute useful winter warmth without driving summer overheating.

• Thermal-bridge control (Ψ-value): low psi-values at junctions. The certified SOLEAL Next 75 frame returns a Ψ of 0.024 W/(mK), helped by an Insulbar thermal break and an aerogel insulation insert.

• Airtightness: tightly controlled air leakage across the sealed window.

• Surface temperature (fRsi): a high factor (0.78 on SOLEAL Next 75) that keeps internal surfaces warm and reduces condensation risk.

• Acoustic, safety and security: performance where the project specification calls for it.

By considering these Passive House window requirements as part of the wider building design, project teams can develop passive window systems that contribute to energy efficiency, occupant wellbeing and long-term operational performance.

Why Aluminium Passivhaus Windows Are Relevant for Commercial Projects

Aluminium conducts heat, so early aluminium windows struggled to reach Passivhaus U-values. However, thanks to thermally broken systems, aluminium has become a preferred material for many commercial developments. It combines structural strength, durability and design flexibility with the ability to create large glazed openings and slim sightlines.

To meet Passivhaus qualifications, aluminium window systems must also incorporate high-performance glazing and carefully engineered frame designs to achieve the levels of performance expected. As with any passive windows, performance depends on the complete system rather than the frame material alone.

For commercial projects, aluminium also offers practical advantages through its compatibility with wider commercial window systems, curtain walling, entrance doors and façade solutions. This allows architects and specifiers to achieve a consistent appearance while maintaining continuity across the building envelope and supporting demanding performance objectives.

Specifying Passivhaus Windows for UK Commercial Buildings

Some projects pursue formal Passivhaus certification; others adopt Passivhaus principles to cut operational energy and improve comfort. Either way, specify the window against the wider envelope from the earliest design stage, alongside:

• Approved Document L (conservation of fuel and power).

• Approved Document F (ventilation and indoor air quality).

• Approved Document O (overheating), where solar gain is a risk.

• Acoustic, security and accessibility requirements for the building's use.

• Durability, maintenance and opening operation.

• BIM/Revit objects, CAD details and performance data for coordination.

Because certified performance depends on the installed detail as much as the product, early coordination between architect, façade consultant, contractor and fabricator is what protects the target on site.

Passivhaus Window Detailing and Installation Considerations

Even the highest-performing Passivhaus windows can fail to achieve their intended performance if installation details are not properly coordinated. Installed performance is just as important as product performance, making careful detailing essential throughout the design and construction process.

To achieve Passive House standards, consider how the window interfaces with the surrounding wall or facade system to minimise thermal bridging and maintain airtightness. Positioning within the insulation layer, together with appropriate airtight tapes, membranes, sealants and support bracketry, all contribute to long-term thermal performance. Drainage, weatherproofing and movement allowances must also be carefully integrated.

Commercial projects often involve multiple contractors and specialist suppliers. Early coordination between architects, façade consultants, contractors and fabricators helps ensure passive house window systems perform as intended once installed.

Integrating Passivhaus Windows with Doors, Façades and Curtain Walling

The performance of Passivhaus windows should always be considered as part of the complete building envelope rather than as an isolated product. Achieving low-energy performance relies on continuity between windows, door systems, façades and other external building elements.

For many commercial developments, Passive House doors and windows are integrated with aluminium curtain walling systems, entrance systems, louvres and façade solutions. Coordinating these interfaces helps maintain thermal continuity, airtightness and weather resistance while supporting architectural consistency across the project.

Working with a supplier that offers integrated façade solutions enables project teams to specify compatible systems more efficiently. A holistic specification approach helps reduce design complexity and improve overall building performance.

Cost Factors for Passivhaus Windows

The Passivhaus windows cost for a commercial project depends on several specification and project-specific factors rather than a single product price. These may include:

• Window size and configuration.

• Frame design and glazing specification.

• Opening types and hardware.

• Acoustic, safety and security requirements.

• Project scale and procurement strategy.

• Installation complexity and airtightness detailing.

• Certification or performance requirements.

• Integration with façades, doors and curtain walling.

Rather than focusing solely on upfront costs, specifiers should consider long-term operational performance, durability and lifecycle value when selecting passive house windows. Early engagement with TECHNAL can help identify the most appropriate Passivhaus windows for your project's technical and performance objectives.

Contact TECHNAL for project-specific specification support.

Commercial Applications for Passivhaus Windows

Passivhaus windows are suitable for a wide range of commercial sectors where energy efficiency, occupant comfort and long-term building performance are priorities.

While performance requirements vary between projects, passive window systems can help support ambitious sustainability targets while maintaining design flexibility.

Typical applications include:

• Healthcare and NHS buildings, where stable indoor temperatures and occupant comfort are essential.

• Schools and universities, helping create comfortable learning environments with reduced energy demand.

• Hotels and leisure facilities, where thermal comfort, daylight and acoustic performance enhance the user experience.

• Commercial offices, supporting workplace wellbeing and operational efficiency. Mixed-use developments, where different occupancy types require consistent building envelope performance.

• Residential developments and student accommodation, where durability, low maintenance and energy performance are key considerations.

By combining thermal efficiency, daylight optimisation, overheating control and long-term durability, commercial window systems can contribute to more sustainable, comfortable and resilient buildings across a wide range of sectors.

Technical Resources for Passivhaus Window Specification

Specifying Passivhaus windows requires access to accurate technical information throughout the design process. TECHNAL provides a range of resources to support professionals when evaluating passive house window systems for commercial projects.

• Available technical resources include:

• Technical product documentation and specification guidance.

• BIM objects, Revit files and CAD details.

• Performance data and technical datasheets.

• Product certifications and declarations where applicable.

• Environmental documentation to support sustainability objectives.

• Specification support from TECHNAL's technical team.

• Training and CPD opportunities.

• A network of approved fabricators across the UK and Ireland.

Whether you're researching Passive House windows in the UK or preparing a detailed specification, TECHNAL digital resources help simplify product selection, improve project coordination and support informed decision-making from concept through to delivery.

Why Choose TECHNAL UK & Ireland for Passivhaus Window Projects?

TECHNAL supports architects, developers and specifiers with high-performance aluminium Passivhaus window systems designed for low-energy commercial buildings.

Alongside technical expertise, we provide specification support, BIM objects, Revit files, CAD details and performance data to help streamline project delivery.

Our systems integrate with doors, façades and curtain walling and are manufactured by a network of approved fabricators across the UK and Ireland. Our team provides support from specification through to installation.

Contact TECHNAL to discuss Passivhaus window specification for your project.