Efficient way of extruding moulding shapes out of walls

Question

I have a model of an apartment, which is all of it a single connected mesh (the vertex for the floors connect with the ones on the wall, etc) and I wanted to extrude small mouldings at the bottom of each wall (0.1m high, 0.025m thick), where it connects the floor, such that the floor would also be pushed by the extruded mouldings. I've been looking around for methods that would introduce the least amount of vertices, and that altered the mesh as little as possible (keep the floor vertices connected to the walls, and the walls to each other). However, I only found solutions using booleans, or curves with bevels. I'm new to Blender, so I was hoping to learn ways of doing this within the Edit Mode of my object.

Here's my current process:

1. Knife tool to cut the top of the moulding

2. Adjust the height of one of the cut vertices to 0.1m, then scale-z x0 the rest of the cut vertices relative to the first one, to align them vertically

3. Extrude all of the cut faces that have the same normal

4. Knife tool to cut an edge along the adjacent wall, and merge the cut with the extruded mesh, to connect both

5. Delete the floor vertices left behind the extruded area, which will result in unseen faces, and connect the other wall to the extruded area.

I'm sure there's a better, easier method to achieve this, right? Deleting the original floor vertices in the last step also deletes the floor faces, which forces me to re-create them later. I could instead merge these extra floor vertices to the extruded ones, but the whole process feels very brittle and prone to create bad geometry, so I was hoping if anyone would have any tips on how to achieve this result in a better way. Doing this on multiple faces at the same time would be ideal.

Let me know if there's any more info I can provide, many thanks!

Answer 1

For the top of your moulding you can choose the front view, activate the knife and cut orthogonally and through the whole mesh (KAC):

For the floor edges, choose the top view and cut the different edges.Then select all the faces on the floor, press AltE > Extrude Manifold and snap on the vertices (it won't leave any interior faces):

Or do a simple extrude up and snap, then go into Select > Select All by Trait > Interior Faces, remove these faces:

Answer 2

Loop cut and extrude the bottom portion you want. Select all of the new top corner edges and give a Bevel Weight to the edges (bevel weight appears as a blue edge in the viewport).

Then use a Bevel modifier with some extra segments to your liking, Limit Method -> Weight, and a Custom Profile.

Changing the profile will model your molding accordingly.