How to get a floor in revit from original curve and offsetted curve

Hello i am trying to make a floor by offsetting the original line and then i want to get a new outline for the floor that is not interscting ie. is a new closed curve, so i can make a floor out of it.
As a newbie i am a little bit stuck in the moment.
Any ideas will be welcome

Try building a closed polycurve with the PolyCurve.ByJoinedCurves node, and offset that.

Thanks Jacob,
the offsetting works, but i want the inner polyline connected with the outer one in that way that it is a closed polycurve afterwards with which i can produce the floor.

Are you trying to make a donut shape, with a hole in it?

Yes, something like that.
in the middle will be a floor that will be later gras and around the gras area shoul be a granite borderstone So i am trying to do both from one outline. In early days of Autocad we had to do this before GPOLY-Command.

it should work in Revit 2022…
Custom packages Rythm and Crumple have the node called Floor.ByCurveLoops.

Thanks for the advice, so in 2019 it will not work?
it should be something like in the image

hm…No this update on 2022 only… But alternatively you can create the floor then you can cut in that floor…spring package have the node called floor opening by curve…

you can try like this…

Thanks _Vijay,
i tried it but without success.
i tried both shaft opening and floor opening from the springs package
i attch my dyn file. Perhaps you see my fault?
I also attach the dwg file with the square and a more complicated formweg.dwg (43.1 KB)
rasen2.dyn (22.9 KB)

Try making it as two C shapes, and join the two when done.

thanks to all, i solved it by make a little gaping between the endpoints.
i combined the points of the offsetted curve and the original curve. the offsetted must be reversed and from this pointlist i created a new curve which is then the outline for the floor.