The Niggling Question of Trickle Vents: “Do we or don’t we?”


One of the earliest subjects discussed with our architect, Peter, was insulation. We wanted it done well – really well!

When we originally moved in, winter 2014 was approaching. One of the biggest issues we soon realised was the incredibly poor insulation. The old house has single brick walls, so no cavity insulation that many people are used to. We also had bare slate tiles laid directly on concrete throughout the ground floor and ill-fitting 1980s aluminium/PVC windows and doors. A rattling conservatory and converted garage room (on 60cm deep foundations) completed the recipe for a naturally very cold house.

And we had moved in with a newborn baby. The simple and obvious immediate and short-term solution was of course to fill the coffers of the local gas and electric supply company. The heating was on so frequently, that in the end we gave up on the timer settings and just left it most of the time. There was only one thermostat installed. This had been placed by the entrance hallway, situated at one end of a long and narrow shaped house. This meant that often the thermostat showed a toasting temperature of around 23C whilst it was actually only about 15C at the other end of the house where our lounge was.

The worst room in the house was the converted garage bedroom. Built on very shallow foundations with a thin single brick wall surround and large low-quality aluminium windows on both the front and back wall meant that this room was like a garage (which it of course actually had been) with two of the walls replaced by huge poorly insulated windows. Think cold and then multiply it by two. One morning when the temperature outside had been 10C, we measured the temperature inside this room to be 8C. Not quite sure how it managed to be even colder than outside, but it was!

With that background, in mind, you will understand why we were so keen to ensure that our renovated house should be very well insulated. Peter recommended various solutions that would ensure we would pass and exceed all the Building Regulations requirements and provide us with a highly insulated and air tight house.

But, this achievement would come with its own potential issues. The more air-tight and well insulated the house, the higher the risk of condensation and other related issues. Apparently, a typical family just going about their daily routine of having showers, boiling kettles, cooking … and breathing … can introduce around 8 litres of water vapour into the air every day! And unless this moisture can find a way out of the house, it could end up as condensation, damp and mould.


Trickle vents are ugly! We really don’t like them and feel that they spoil the look of windows.

The Building Regulations in the area of ventilation is not that easy to understand for a layman, but what we found was that there area effectively five options given for ventilation. Which of these routes to follow depends on various factors including, the air permeability, of the house.

It was all getting a bit confusing, so we decided it was time to revert to the professionals.



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