Need help with Network Surface in GH

I am making the following shaped plan and I have constructed it using 3-point arcs. And I want to generate a Network Surface from them to proceed to make ideal subdivisions on it using Mesh surface. But when I try to generate the Network Surface it shows ‘null’. I see that the arcs have been selected in different orders but I am unsure about how to get them to the right order. Could someone please help me? I am quite new to Rhino and Grasshopper.
Please find my files attached. Thanks in advance!

RESTAURANT method - 05 - 22-06-2023.3dm (3.8 MB)

RESTAURANT method - 05.gh (18.6 KB)
3dm) (3.8 MB)
sZaMFPTwK1fryOvGnSPafHANw.jpeg)

Hi Andrea - please see Rhino’s Help on how to arrange curves for a network surface - this is not a suitable set of curves -

https://docs.mcneel.com/rhino/7/help/en-us/index.htm#commands/networksrf.htm#(null)

http://docs.mcneel.com/rhino/6/training-level1/en-us/Default.htm

In this case you can use a BoundarySurface

-Pascal

Hi,
Thank you so much for the reply and for letting me know. Actually when I use Boundary Surface, my subdivisions turn out like this:

And when I try subdivisions using MeshBrep and Settings (custom) I get subdivisions like this:

Is there any way to not get those triangles at the boundaries but straight subdivisions at the boundaries too?