Fixed (non-opening) window in kitchen -- possible?

Looking at replacing our kitchen window with a fully glazed (picture) window. It's about 1750mm x 1250mm, and so all options at that size are fixed (non-opening).

Is this allowed, or must the window be fully opening to allow for forced ventilation?

I don't want the gas-safe installer to refuse to install the oven due to e.g. lack of ventilation.

The kitchen also has a door to the outside, door to the hallway (which also has a door to the outside), and 2 velux windows that are out of reach.

The existing window has trickle vents, so I understand that any replacement window must have those too -- but the rules on opening seem less clear to me.

Rules used to be an opening door or window to outside required, I don't think you will have trouble but why not ring the gas installer for confirmation.

Edit gas cookers cannot be fitted under a window fire risk from curtains and (dim) people reaching over to open or wipe while the cooker is on!

Oh I haven't booked them yet... will be a fair few weeks til I'm ready for them!!

It does look like the door should suffice!

Certass/Fensa rules state that you can not make ventilation any worse than existing , so if you take out an opening window , you are supposed to put back an opening window.

BUT ...... who would know....