Airtightness and Vapour Control Membranes – Intelligent Membranes Passive Purple Range

Case Study: Passive Purple Airtightness at Unity Campus

Location: Unity Campus, Cambridge

Products Used: Passive Purple External, Passive Purple Internal, Airtight White

Package: Guaranteed Airtight Supply & Install

Sector: Commercial / Office Development

Project Overview:

Unity Campus is a leading business and science hub in Cambridge, designed to deliver high-specification, sustainable workspaces. The development team required a building envelope solution that achieved superior airtightness, supported long-term energy efficiency, and aligned with the project’s low-carbon objectives.

The Challenge:

• High-performance targets: Meet airtightness levels approaching Passive House standards.
• Mixed construction methods: A Combination of steel frame, concrete, and composite cladding.
• Sustainability goals: Reduce operational carbon footprint while maintaining occupant comfort.

The Solution:

Intelligent Membranes provided a full Guaranteed Airtight Supply & Install Package, incorporating:

• Passive Purple External – Applied as a vapour-open, airtight weather barrier to the external walls, allowing the building fabric to breathe while preventing moisture ingress.
• Passive Purple Internal – Delivered internal airtightness and vapour control, reducing heat loss and improving efficiency ratings.
• Airtight White – Used in visible interior areas where a clean white finish was required without compromising airtight performance.

Application was carried out by our specialist team using spray, roller, and brush techniques to ensure complete coverage — even in complex junctions and service penetrations.

The Results:

• Achieved airtightness performance exceeding project targets.
• Seamless airtight layer protecting against uncontrolled airflow and moisture penetration.
• Improved building energy performance, contributing to sustainability goals.
• Efficient application, keeping the project on schedule.