0.04 ACH at Oxford University’s Collections Storage Facility - Airtight White Delivers on Glencar’s First Passivhaus Project

Oxford University Collections Storage Facility | South Marston, Swindon | Passivhaus Airtightness Project

The Oxford University Collections Storage Facility demonstrates how Intelligent Membranes' complete airtightness system delivers exceptional performance on world-class projects. Airtight White, IM Primer, IM Airtight Fleece Tape, GOAT Sealant and The GOAT were used together to create a seamless airtight vapour control layer across walls, roof junctions and service penetrations. The result was an outstanding 0.04 ACH pre-air test, significantly exceeding the 0.3 ACH design target and showcasing the effectiveness of a fully integrated airtightness solution for Passivhaus construction.

INTERNAL

Airtight White - Vapour Control, Airtight & Smoke Tight Paint (11.4kg) - Spray / Roller Applied

£99.99

Pre-air test result: 0.04 ACH on the ancillary building. Our guarantee: 0.6 or lower. Smashed it.

Airtight White liquid airtight vapour control membrane spray-applied to blockwork walls

The project

The Oxford University Collections Storage Facility at South Marston, Swindon, is a climate-controlled archive store. Commissioned by the University’s Gardens, Libraries and Museums, the expansion, a new climate-controlled chamber and a dedicated Spirit Collection Store, will safeguard collections from the Bodleian Libraries and the University’s museums: more than 10 million books, manuscripts and irreplaceable artefacts.

Buildings like this are designed to Passivhaus Classic standards for a simple reason: stable temperature and humidity protect fragile materials, and you can’t have stable conditions with uncontrolled air leaking through the envelope. The main storage chamber’s airtightness target: 0.3 air changes per hour.

Main contractor Glencar took it on as one of their first Passivhaus projects, and asked us to deliver the airtight line under our guaranteed 0.6 ACH or lower installation service.

The system

Liquid airtightness is a system, with the right tool at each part of the build-up:

Joints first - IM Fleece Tape across the panel joints, bedded in with Airtight White brush grade for a fully bonded, plaster-ready detail.
Prime - walls primed with IM Primer to give the membrane maximum adhesion across the substrate.
Over-goat the lot - Airtight White spray-applied wall to wall: one seamless, VOC-free airtight vapour control layer, white enough to leave on show.
The roof - every roof joint sealed with The GOAT Sealant and coated over with The GOAT (7.5kg), keeping the airtight line continuous where roof meets structure.

IM Primer and IM Fleece Tape being installed to 18 metre high storage facility walls from a scissor lift

The result: 0.04 on the ancillary building

The pre-completion air test on the ancillary building at the facility — a separate, smaller building from the main storage chamber — came back at 0.04 ACH, fifteen times tighter than our own 0.6 guarantee. That number wasn’t luck: it was our installation team and Glencar’s site team working the detail together, joint by joint, penetration by penetration.

The site has given the project manager a new name: 004 - licence to seal.

What happens next

This was the pre-test; the final air test comes at completion, and we’re excited to see where it lands. With the envelope performing at this level, Oxford University’s collections will sit in stable, energy-efficient storage conditions.

Want a guaranteed air test result?

This project ran on our guaranteed 0.6 ACH or lower supply-and-install service: we spec it, we install it, we stand behind the number. If your project has an airtightness target it can’t afford to miss, talk to us - or send us your drawings and we’ll mark up the airtight line for free.

Pre-air test result: 0.04 ACH on the ancillary building at Oxford University’s Collections Storage Facility in Swindon — fifteen times tighter than our own 0.6 ACH guarantee. How Airtight White, IM Fleece Tape, IM Primer and The GOAT delivered on one of Glencar’s first Passivhaus projects.