New build - ventilation

[heytesto]

Hi all,
I've purchased a new build, (2 bed semi, timber framed). The builders are on finishing over the next couple of weeks.
The bathroom is internal upstairs, no windows. The electrician has fitted an extractor fan in the ceiling, but today I went up in the attic and pulled back the fibreglass to see the fan is just poking through the plasterboard and concealed by the insulation. No ducting to outside. I'm sure this is bad practice.

I just want to know the exact facts and regs before confronting the site manager.

1. Must the fan be ducted to outside?

2. Downstairs toilet has an openable window. The electrician has provided a fan isolator above the door and has terminated the cable within a surface box and blank on the wall, but no fan is installed. Leaving the window open would be a security risk. Is a fan required under the building regs?

3. The kitchen has an openable window. Cooker hood is being installed to recirculate. Do kitchens need extraction?

Please, I know many people will want to contribute but I respectfully ask that trades people only reply as I am looking for the definitive answers.
Thanks in advance.

 

[^woody^]

1. Yes

2. A window with an opening casement minimum 1/20th of floor area is acceptable instead of a fan.

3. Extract fan is required, vented to outside. Either a fan, or a cooker hood.

The extract rates of the any fans depend on whether they are boost only or provide constant trickle ventilation too.

 

[heytesto]

Thank you, I thought the same. Not sure how they're going to get around the kitchen fan, no wall space.
I was aware of the 1/20th floor area but that was years ago, I wasn't sure if regs had changed.
Cheers anyway.