In this bonus lesson we cover some key points regarding windows and noise.
Here are some examples of mechanical ventilation options:
If you live near a busy road, then I would recommend acoustic triple glazed windows supplied without trickle vents and then install wall ventilation or mechanical ventilation to avoid the noise coming in directly through the new acoustic windows.
The wall ventilation or mechanical ventilation can bring fresh air into the room from the back of the house or somewhere around the property where there is less noise.
If you do not have trickle vents on your new acoustic windows, then building regulations require you to have background ventilation, i.e., not mechanical ventilation for the house.
Building regulation require background ventilation of 8000 square millimetres for a habitable room. Basically, an air brick the size of a brick that vents outside that will allow fresh air into the room.
Air bricks are available from the local builders merchant about the size of a brick.
You cannot utilise existing ventilation like the suspended floor or ventilation in the loft which allows the roof to breath, it must be fresh air into the room to meet building regulations.
You can see this will still let noise into the room especially high frequency so it best to either get fresh air in from the other side of the house or use acoustic ventilation.
So what about car fumes and air pollution?
Pollution is not covered under building regulations but the requirement for fresh air is. This is because they argue you are just as much at risk of damp and mould type of problems inside the house as you are air pollution from say a busy road.
There is a grey area around air pollution if you live right next to a busy road and this would be an exceptional case, which you will need a report proving this from a professional on the air quality for the local building inspector to approve. However, it is seen that fresh air into the room to prevent mould and damp is just as harmful and local building control officer may still not approve.
The company installing the new acoustic window that has been manufactured without trickle vents is responsible for ensuring it meets building regulations when it is installed by ensure the room has adequate ventilation.
The person installing it can be FENSA registered installer and therefore does not require building regulations and they will issue a certificate of compliance with the building regulations. FENSA is a competent person scheme just like ‘Gas Safe’ and
NICEIC for Electrical. A FENSA registered installer will put adequate ventilation either trickle vents or mechanical ventilation or background wall ventilation or order to give you a FENSA certificate for your house folder if you were ever to sell the house. (A FENSA certificate is a certificate of compliance)
A non FENSA registered person such as a DIYer could install the window themselves but in order to get a certificate that shows your new window meets building regulations, they would need a building application. They can get this by applying for a regular building application online and have the building control officer visit a couple of times, once when the window is going in and again when the project is completed. The building control officer will then issue a certificate which confirms compliance with the building regulations.
What else can you do….
You could install a secondary window. This is different from secondary glazing. A Secondary window does not have to have trickle vents. So maybe consider having your main exterior window a cheaper window with trickle vents to meet new building regulations and then install a secondary window on the inside that has all the acoustic properties an acoustic window has such as laminated panes and no trickle vents.
These windows normally open inwards so not always practical for bay windows.
Another option would be secondary glazing that also does not require trickle vents. We find that there is a magic air gap of 75-100mm between the existing windows and the new secondary glazing that is required to get the best reduction in noise from most road and aircraft noise.