Bi-fold with traffic door vs separate back door?

Doozergirl

...another reason to choose sliding doors 😬

YellowCarBlueCar

Indeed - that is a concern.  It's a south-facing single-aspect room, and as it will be 6.3m deep we're adding a roof lantern to provide light to the back of the room.  A 3.6m glass door plus a lantern has the potential to create an unwelcome amount of passive heat in the summer.

With the glass door being the only proper ventilation (I'm not counting an extractor fan), then the ability to do something akin to cracking open a window is something we will probably need.

My main thoughts against sliding doors is the fact that this will be the main access to the back garden, and Mrs YCBC is slight of stature so won't be keen of shifting the inertia of a sliding panel whenever she wants to pop into the garden.

Doozergirl

Buy the right door and it can be moved with a finger, pretty much. 

https://youtu.be/KGV6uB9TGAE