A personal reflection by Andrew on Patrick Gallagher’s legacy of joined-up thinking
I was recently passed a series of documents and articles by Patrick Gallagher, written with Howard Morley, dealing with dampness, condensation, mould growth, ventilation, energy efficiency and, crucially, the human consequences of getting these things wrong. I will be honest: reading them was a humbling experience.
Not because the subject matter was unfamiliar, most of us working in the built environment encounter these issues regularly, but because the clarity, breadth and joined-up thinking on display felt decades ahead of where the industry still finds itself today. I’m not sure I can do Patrick’s work full justice in a single blog, but what follows is my personal reflection on some of the themes that struck me most, and why I believe they are even more relevant now than when they were written.
These weren’t just technical papers, they were warnings
What quickly becomes apparent when reading Patrick’s work is that it was never just about moisture or ventilation systems. It was about responsibility.
Dampness is not treated as a surface defect. It is presented, correctly, as a systemic failure, with consequences that cascade through buildings, people and public systems:
- Damp fabric drives massive heat loss
- Heat loss exacerbates fuel poverty
- Fuel poverty damages physical and mental health
- Poor health increases pressure on the NHS and public services
- Ineffective interventions waste public money and erode trust
This was not speculation. The papers are grounded in building physics, real case histories, legal context and health data. The message is blunt: you cannot fix these problems in isolation.
As Patrick put it, with characteristic clarity:
“It is essential, therefore, that the dwelling be made and kept ‘dry’ and that internal humidity levels are controlled at the healthy optimum of 50% relative humidity, if insulation measures are to have any beneficial effect whatsoever.”
That sentence alone captures how far ahead this thinking was and how often it is still overlooked.
“The Knowledge” and why it still matters
One phrase that stayed with me was Patrick’s repeated reference to “The Knowledge”, borrowed from London taxi drivers, meaning not theory or guidance notes, but a deep, practical understanding of how things actually work in real homes.
It is a quiet but uncomfortable challenge to all of us in professional roles.
Without that knowledge, we default to:
- cheapest-first specifications
- cosmetic or surface-level repairs
- ventilation that technically “complies” but functionally fails
- insulation installed into damp fabric
- and, too often, blaming occupants when outcomes are poor
Patrick was clear: if we don’t understand the links between moisture, heat, air movement, health and behaviour, we will keep taking the wrong road, regardless of how good our intentions may be.
This avoidance of comprehensive solutions is particularly damaging in an era focused on energy efficiency. Patrick consistently advocated Heat Recovery Ventilation (HRV) precisely because it addresses the problem systemically. It dries the building fabric, controls internal humidity, improves indoor air quality and, crucially, reclaims up to 86% of the heat that conventional extract-only systems simply throw away. It is not an add-on, it is a corrective strategy.
The uncomfortable truth: we still repeat the same mistakes
What I found most striking is how familiar many of the failures described still feel today:
- Condensation dismissed as “lifestyle”
- Mould treated as a cleaning issue
- Ventilation avoided for fear of liability
- Energy efficiency measures undermined by trapped moisture
- Short-term savings creating long-term harm
Despite better standards, better products and better awareness, damp and mould remain among the most common causes of complaint, distress and litigation in housing.
That tells us something important: this is not primarily a technology problem, it is a thinking problem.
Why this matters even more today
If anything, the issues Patrick highlighted have intensified.
Homes are more sealed. Energy costs are higher. Occupants are under greater financial pressure. Expectations of comfort are higher. And the health impacts of poor indoor air quality are now far better understood.
Against that backdrop, the core message of this work feels remarkably current:
- Keep buildings dry
- Control humidity properly
- Recover heat instead of discarding it
- Prioritise health before appearance
- Train professionals to understand the whole system, not just the symptom
None of this is radical. All of it is achievable. And much of it was laid out clearly years ago.
A personal note
I’m grateful to Patrick for sharing this material with me and for allowing me to reflect on it publicly. Reading his work reminded me that professionalism in our sector is not just about compliance, it is about care for occupants, for public resources and for the long-term performance of the buildings we influence.
With Patrick’s permission, I hope to explore ways of making more of this thinking visible to a wider audience. It deserves to be read, not as history, but as guidance we still haven’t fully absorbed.
If this blog does nothing more than prompt a few people to pause and reconsider how they approach damp, ventilation and indoor air quality, it will have been worth writing.
Final thought
Some ideas don’t age because they were never properly listened to the first time.
We are grateful to Patrick for sharing this foundational material, and we invite the ISSE community to reflect on these principles. Where are you seeing the biggest current failures in joined-up thinking on damp and ventilation? And how can we collectively apply The Knowledge to drive genuine, systemic change?
We’d welcome your thoughts and experiences below.
