Why do I need a trickle vent?
Why do I need a trickle vent?
While it might be tempting to close trickle vents in winter – it’s important to always keep them open and unblocked.
Why do I need a trickle vent?
In England and Wales, the Building Regulations were updated in 2022 as part of the government’s efforts to make homes more efficient – and those updates have had a big impact on windows and doors.
Updates to Part L of the Building Regs, which is concerned with thermal performance, mean that windows and doors now have to meet higher efficiency standards (you can read more Part L here and here), while updates to Part F mean that almost all windows, bifolds and sliding doors now also have to have trickle vents fitted to improve ventilation. That’s because old windows will almost inevitably have been leaky compared to new ones and energy efficiency upgrades can’t reduce the amount of useful ventilation in your home.
You will see suppliers like AluK have been quick to add integrated deep head profiles to our high performance frames like the 58BW HI system to accommodate trickle vents as neatly and unobtrusively as possible – so you shouldn’t really notice the difference.
For some buyers, the two new regulations may seem contradictory, because you are effectively required to cut a hole in a new high performance window frame. But adequate ventilation is essential for maintaining a healthy indoor environment. Without it, there will be more substances in the air that can cause harm to you and your family, and more condensation generated by everyday activities like cooking to showering which can get trapped inside. Over time, this can cause damp and mould growth which will damage your home and, in extreme cases, lead to respiratory illnesses for you and your family.
Window and door fabricators and installers are now required by law to manufacture and install frames with trickle ventilation in almost all cases. The only meaningful exceptions are:
- If you already have a MVHR (Mechanical Ventilation Heat Recovery) system in your home providing continual background ventilation
- If you can prove that replacing the old window or door will not reduce the amount of useful ventilation in your home
- If your house is listed or in some conservation areas (in which case, you will need to discuss options with your installer)
- If you have more than one window in a room and you can prove you meet the minimum EA (Equivalent Area) background ventilation requirement for that room with trickle vents fitted in just one of the windows. (For living rooms, bedrooms and kitchens, the EA is 8000mm2 and for bathrooms it is 4000mm2).
While it might be tempting to close trickle vents in winter – it’s important to always keep them open and unblocked. Remember, they are only there to keep your home healthy and comfortable.
