Purchase recommendation attic ladder / floor ladder

Hello Forum members,

I am currently dealing with the selection of a suitable attic ladder for our new building.
We have an opening size of 80x150 and the ladder should be reasonably insulated.

I need information on the following questions:

[*]Which provider(s) are recommended?
[*]Is an on-site consultation with a specialist advisable?
[*]What material? Wood or metal
[*]How is the installation done?

Regards
André

To1: The DOLLE CLICKFIX 76 is recommended. Good price-performance ratio. Very good U-value of 0.49 W/m²K. Installation possible alone, as everything is clicked together.

To2: You can do that.

To3: The attic ladders are usually made of wood.

To4: Installation instructions are always included. The attic ladders are available in different lengths and widths. They are screwed to the side of collar beams. For concrete ceilings, doweled. Possibly supported with slats.