If I understand correctly you would like to make a dtm out of vectors for the tips on how to do it see gis.stackexchange.com/questions/18116/… To add the elevation data to the attribute table just add a columne name i.e. Z and this is where you will manually add it in while digitizing the plan.

Thanks for the info. I have changed the link to GitHub repo of the plugin.

any updates in this matter? the answer below does not relate to the question posted above.

I will have to experiment with it, its just not prepared for mobile devices and by that its not that stable in the free option. In short You can view it through a browser on a mobile device, but I would prefere a little better quality of use. Its a start and better than nothing - thanks for the direction :)

Yest It is a possible option, just that the mobile client is only in Pro option which in the longer run would be a bit expensieve - I think it is a good option If You have more projects to publish :)

so what You are suggesting is a model where DTM and the housing features are merged in one?

The plugin is working just fine and You will finde it in the main Plugin Repository look for Colour Scale Bar