Trickle vents: Education is needed

David Thornton, chair of the Window Company (Contracts)

The upcoming requirement, under Part F of the building regulations, to fit trickle vents in virtually all replacement windows, is causing quite a stir among installers. Many complain about how unpopular they are with homeowners.

That’s completely at odds with our experience in the social housing sector. The vast majority of residents in homes where we are fitting windows understand exactly why they are necessary. We actually get very little pushback. If we do, our fitters are fully briefed to explain the benefits of background ventilation – and the likely cost of remedials.

I was surprised then to see the figure shared recently by Dean Bradley of Glazpart that, of 55 sites audited by the government during the consultation on the new building regulations, only two were fully compliant even with the 2006 version of Approved Document F. No wonder that there will now be an Installation and Commissioning checklist that has to be completed and handed over to the homeowner after a window installation, that includes sign off on the background ventilation. Knowingly making a false declaration on that will invalidate either Fensa or Certass certification.

As I see it, there’s nowhere really to go in terms of non-compliance. The rules state that a replacement installation should make the ventilation ‘no worse’, and the fact is that if you replace any double gasketed PVC-U window with a like-for-like replacement, it will increase the air tightness simply because the original will have deteriorated in performance over time.

My understanding is that it won’t be enough to take a photograph to justify not fitting a trickle vent either – effectively, you’d have to complete a before and after air tightness test, and that would be completely unviable. I actually think it will become increasingly difficult during the course of this year for installers to buy frames that aren’t routed for trickle vents. Certainly, fabricators we have spoken to plan to make inclusion of trickle vents the default option on their ordering systems. As soon as they effectively become compulsory, where’s the incentive for fabricators to encourage the breaking of the rules?

Obviously, there are relatively few physical inspections carried out to police the building regulations, but that shouldn’t be a reason for installers to ignore them. Maybe what’s needed is a better communications programme to persuade homeowners of the benefits of trickle vents and, in a post-Covid world, reinforce the importance of bringing fresh air into their homes?

David Thornton
Chair of the Window Company (Contracts)