Oxford Brookes University – Airtightness Delivered with Passive Purple

Willmott Dixon recently completed the new Faculty of Technology, Design & Environment at Oxford Brookes University’s Headington Hill campus. Designed by ADP Architecture, the building provides cutting-edge facilities for engineering, creative technologies, and digital disciplines.

At the heart of its performance is a carefully planned airtightness strategy — built around Passive Purple, the liquid applied airtight vapour control membrane from Intelligent Membranes.

Project Requirements

The Oxford Brookes development needed an airtightness solution that would:

  • Meet stringent performance targets.

  • Provide long-term durability.

  • Be quick and efficient to install on site.

  • Work seamlessly with the blockwork and external wall insulation (EWI) system.

With multiple high-spec workshop spaces, wind tunnels, manufacturing labs, and the Oxford Brookes Racing Team’s Formula 1 workshop, the building demanded precision climate control, low energy consumption, and protection from moisture ingress.

Why Passive Purple Was Chosen

Passive Purple is a liquid applied airtight membrane and vapour control layer. It was spray-applied directly to the blockwork to create a continuous seal before installing the EWI.

Key advantages for this project included:

  • Superior airtightness – minimising heat loss and improving energy efficiency.

  • Integrated vapour control – preventing condensation and safeguarding the building fabric.

  • Speed of application – covering large wall areas quickly and effectively.

  • Versatility – able to seal complex junctions, penetrations, and interfaces.

Detailing for Airtightness

For finer work, Passive Purple Brush was used. This fibre-reinforced formula bridges gaps and adheres to multiple substrates, making it ideal for sealing scaffold tie holes, service penetrations, and awkward junctions.

Windows were set forward after application, with EPDM membranes bonded directly to the blockwork to deliver:

  • Airtight and watertight seals.

  • Reduced thermal bridging.

  • Improved overall performance.

Results

By integrating Passive Purple liquid applied vapour controls, Willmott Dixon and ADP Architecture achieved a high-performing airtight envelope that supports the university’s sustainability goals while ensuring comfortable, stable internal conditions for students and staff.

This project demonstrates how modern liquid applied airtightness solutions outperform traditional tapes and membranes — speeding up installation, improving performance, and reducing long-term risk.

Products Used on This Project – Oxford Brookes University

1. Passive Purple – BIG BOY – Vapour Control Paint (11.4kg) – Spray / Roller Applied – Intelligent Membranes
A spray-applied, airtight, and vapour control membrane used internally on walls and ceilings to achieve a continuous, seamless barrier. This ensures superior airtightness, prevents condensation, and maintains insulation performance Fibre-reinforced airtight coating applied to junctions, service penetrations, and tricky detailing areas. Used prior to spraying to seal potential leakage points.

2. Passive Purple Brush – Home Pack (6.9kg) – Vapour Control Paint – Brush Applied – Intelligent Membranes
Fibre-reinforced airtight coating applied to junctions, service penetrations, and tricky detailing areas. Used prior to spraying to seal potential leakage points.

3.Airtight Tape – Intelligent Membranes
Specialist airtight tape used around windows, doors, and complex junctions to reinforce the membrane and eliminate air leakage pathways.

4. Supergrip Primer (10kg) – Roller – Intelligent Membranes
Applied to specific surfaces to enhance adhesion of the Passive Purple system, ensuring a robust and durable finish.

5. Passivhaus Airtight Sealant – 600ml – Intelligent Membranes
Used for precise sealing in critical areas, particularly around window and door frames, to maintain the integrity of the airtight envelope.

Liquid applied airtight membrane providing vapour control before external wall insulation.Airtight and vapour-tight membrane installation on educational building project.Intelligent Membranes Passive Purple applied for high-performance airtightness at Oxford Brookes.