Drawing professional heights in blender for the beginning of landscape planning

Hello,

i asked for a few weeks about the possibility to have heights in text in blender.
Intelligent Text for height Anotation - Support / Modeling - Blender Artists Community

The answers were very helpfull and i could use it in my file.
I use blender for making renderings but i also use it in the real planning process.
I know that there are tools like vectorworks to create very good terrain,
but i was wondering if there is a script or something to create correct heights in blender.

My problem is that i want to have something like a pencil with that i can say i want to have precice 1 meter at this position and than the planning is changing i want to go down to precice 0.5 meter.

I think blenderbim is an add on that works on using blender professional for planning. I know that blender is unable to create plans and its unable to have something like a plan in 1:100 or 1:50 too but i think it would be nice to have a tool just for the beginning to find out if its looks nice what i have in my mind. For that precission in the heights would be nice!