Internal gutter: How to implement cost-effectively?

Hello everyone,

we are currently very uncertain regarding our roof construction/the carpentry work. We would like a clad shed roof with an internal gutter, but we do not know how to install the gutter cost-effectively in this setup. It should look something like this:


Our architect (old school) has planned the following construction for the eaves side:


As you can see, he wants to work with a bracket extension. This worries me regarding the costs.
Do you see any other possibilities? For your information: Due to the shallow pitch (8°), it will probably be a membrane roof.

Thank you very much in advance.

Is there no additional insulation layer (Pavatex or similar) over the rafters? In this detail, I see ventilation above the rafters, correct? At an 8-degree roof pitch, a zinc double standing seam roof might be an alternative, if one likes it.

Isn't there another insulation layer above the rafters (Pavatex or similar)? In this detail, I recognize ventilation above the rafters, right? With an 8-degree roof pitch, a zinc double standing seam roof might be an alternative, if you like it.

- No, apparently everything is to be insulated between the rafters.
- Exactly, there should be ventilation.

The question remains: How can this "internal" gutter be implemented/concealed cost-effectively without having the complicated construction at the eaves?

.. and always remember that it remains cleanable.