Architect & Specifier Hub
Why Specify Intelligent Membranes?
Intelligent Membranes produces the UK's first Passivhaus-certified liquid-applied airtight, vapour control and waterproofing membranes. Liquid application eliminates the failure points inherent in overlapping sheet membranes and tapes — giving your project a seamless, independently tested airtight layer that performs reliably over the building's lifetime.
🏆 Passivhaus Certified
Certified by the Passivhaus Institut — the highest performance standard in airtightness. Suitable for Passivhaus Classic, Plus, and Premium projects.
📋 BBA Certified
Passive Purple Internal and Passive Purple Brush hold BBA Certificate 22/6002 — independent third-party assurance for specification confidence.
🔬 WUFI Database Listed
Tested material properties registered in WUFI, enabling moisture control design compliant with EN 15026, ASHRAE 160 and DIN 4108.
🏛️ RIBA Product Selector
Listed on the RIBA Product Selector — reference our products directly within your RIBA workflow and NBS specifications.
🔥 Fire Rated Options
Passive Purple X and Passive Purple External carry Class B fire ratings, suitable for facades on buildings over 11m and Approved Document B compliance.
🌿 Low VOC
Water-based, low-VOC formulation assessed for indoor air emissions — suitable for occupied buildings, schools and healthcare projects.
Certifications at a Glance
Products Available for Specification
| Product | Application | Key Certifications | Typical Use |
|---|---|---|---|
| Passive Purple Internal | Spray / Roller | Passivhaus, BBA, WUFI | Internal VCL & airtight layer — new build & retrofit |
| Passive Purple Brush | Brush | Passivhaus, BBA | Junctions, penetrations, small areas, blockwork sealing |
| Passive Purple External | Spray / Brush | Passivhaus, Fire Rated Class B | External airtight & weatherproof facade membrane |
| Passive Purple X | Spray / Brush | Class B Fire, Passivhaus | Fire-rated facades, buildings over 11m |
| Passive Purple Retrofit | Spray / Brush | Passivhaus | Retrofit airtightness on existing masonry & substrates |
| Airtight White | Spray / Brush | Airtight, VCL | Internal airtight membrane where white finish is required |
| Poseidon | Spray / Roller | Waterproof | Bathroom, wet room, internal waterproofing (internal use only) |
| FRED | Spray / Roller / Brush | Warrington Fire Tested | Intumescent flame retardant coating — internal & external |
NBS Specification Support
We provide NBS specification clauses for our key products to make it straightforward to write Intelligent Membranes into your project specification. Our products are listed on the RIBA Product Selector, so you can link directly from NBS Chorus to our product pages.
Request NBS Clauses
Contact our specification team to receive ready-to-use NBS clause wording for Passive Purple Internal, Passive Purple Brush, Passive Purple External and Passive Purple X. We respond within one working day.
Request Spec Clauses View on NBS Source
Technical Data & CAD Details
📄 Technical Data Sheets
Product datasheets covering coverage rates, application method, substrate compatibility, performance data and curing times.
📐 Application & Coverage Rates
Detailed application guides including coverage rates per substrate type, recommended film thicknesses, and quantities for estimating.
🏗️ Junction Detail Drawings
Wall–roof, wall–floor, window reveals, service penetrations and other critical airtightness junctions. Contact us to request specific CAD details for your construction type.
📊 WUFI Hygrothermal Data
Tested material properties registered in the WUFI database for use in condensation risk and moisture transfer analysis.
RIBA-Accredited CPD
We offer RIBA-accredited CPD seminars for architectural practices, contractor teams and building control officers — available in-person or online, free of charge.
CPD Topics
- Airtightness in Modern Construction — UK standards, methods of achieving airtightness, and how liquid membranes compare to sheet systems
- Passivhaus Principles for Mainstream Projects — The five Passivhaus principles and how to apply them without full certification
- Retrofit Airtightness & Vapour Control — Condensation risk, vapour control strategies and liquid membranes in retrofit scenarios
- Fire-Rated Membranes & Facade Compliance — Fire performance requirements for membranes in facades post-Grenfell
- Waterproofing & DPM Solutions — Liquid-applied waterproofing for wet rooms, roofs, floors and DPM applications
Book a CPD Session
Sessions are free, approximately 45–60 minutes, and available in your office, on site, or via Teams/Zoom.
Book a CPD SessionHow to Specify
- Identify the right productUse our Solutions pages or contact our spec team to confirm the correct product for your substrate, application and performance requirement.
- Download technical data and certificationsAll datasheets, BBA certificates, Passivhaus certifications and WUFI data are available in our Brochures section.
- Request NBS specification clausesWe provide ready-to-use NBS clause wording. Contact us and we'll respond within one working day.
- Request CAD junction detailsWe supply CAD details for critical airtightness interfaces. Contact our technical team with your construction type.
- Arrange a technical consultationFor complex projects our team can review drawings to advise on airtightness strategy, specification and coverage quantities.
- Locate an approved installer or order directView our Approved Installer & Distributor list or order products from our online store.
Talk to Our Specification Team
Our technical team supports your specification from design stage through to site. NBS clauses, CPD, WUFI data, site surveys — we respond within one working day.
Contact the Spec Team Download Brochures