It was a long time coming but the new version of this important standard was published at the end of July. Running to almost 170 pages and costing £350 (£175 for BSI members), it is hardly light reading on a budget. Before we get into any opinions a little introduction might be useful….

Redefining the scope of 5250

Until July, BS 5250:2011 carried the title: Code of Practice for Control of Condensation in Buildings. Quite a narrow definition that produced a relatively focused document with a single consideration. The publication of the BSI white paper ‘Moisture in buildings: an integrated approach to risk assessment and guidance’ written by Chris Sanders and Neil May through STBA (Sustainable Traditional Buildings Alliance), advocated a holistic approach to the issue of moisture in buildings.

The opportunity to make the vision real came along as BSI agreed to redefine the scope of 5250. The goal seems to have been to create a Code of Practice that sets the formulas for the management of all forms of moisture in all buildings, everywhere.

The enormity of the subject should not be underestimated!

Taking a standard for condensation management and attempting to morph it into an all encompassing reference manual for everything has proved to be a challenge. Though we can’t speak from direct knowledge of what happened behind closed doors (the PCA was invited to be part of the review committee only at the very end of the process), we can make some educated observations.

The enormity of the subject should not be underestimated. Consider the fact that a diverse range of people involved in the task. Very bright people from contracting, academia, building heritage, trade groupings, consultancy, new build, renovation, retrofit and insurance took on the task of setting out in one text that attempts to inform how all forms of moisture should be managed in all situations, in all buildings. You can only wonder how on earth they even began the job.

How they managed to deliver the finished text is matter of record, but did they succeed? Truth is, and it gives me no pleasure to say it, but it’s my view that they didn’t quite pull it off.
That is not to say the final document isn’t of value. The information contained within the pages of the code is all good stuff. There might be areas where some people had rather wished things were different and others where detail is a little thin, but all in all, what is in the code is accurate and valuable.

If you are considering new build, refurbishment, or energy saving measures, those seeking to work out how to manage or avoid atmospheric moisture problems are pretty well served. My own view is that the challenges of presenting, diagnosing and managing water ingress, are less well represented.

An accessible, intuitive, definitive document, or not?

So, is BS5250:2021, the accessible, intuitive, definitive document that guides the user through a “whole house approach” to moisture management, which Neil May and Chris Sanders envisaged in their white paper?

Well, I’m not sure it is. The document sharpens its focus on atmospheric moisture while drawing in other forms of moisture risk. It has almost everything you might want to know about condensation while really only providing an introduction to the prevention, diagnosis and management of other moisture issues.

A valiant effort to change how we think about moisture in buildings

Can it be used as a definitive Code of Practice for those who wish to successfully manage all forms of water, in all buildings at all times everywhere?

I don’t think it quite delivers that this time, but it does represent a really valiant effort to change the way we think about moisture in buildings. Perhaps the project stumbled a little when the vision of what it was meant to be, dimmed ever so slightly as inspiration for the task was so tragically lost to us late in 2018…