Hoooray
Yes, this and chimneys. Not just a pipe sticking out of a gap, but a block that looks like a chimney, snapping to the placed pipe, showing the smoke.
was just about to suggest this, just a simple block probably tier 2 that connects to pipes for the purpose of connecting pipes through a wall. If you'd like to just have a "pipe" wall, floor, block, etc configurable like bricks have aquaduct blocks then that's great. Otherwise just a simple block that can connect on two sides to pipes.
Why not make it so that building blocks can be placed onto the same block as a pipe (could do the same with wires too), that way people have to 'open' the wall, place the pipes down, place the wall again over the pipes.
Speaking of pipes (and mechanical power transfer cogs/shafts, and also wires/cables) Maybe it's just better to make them a totally different entity placed on their own layer of the 3d space? They would just connect to corresponding sockets of crafting tables and other objects and they would not collide with building blocks but simply pass through them. This way they won't require any additional blockform combinations. To balance that maybe they should require much more calories to be built through existing blocks
This could also be used as a way to "tighten up" pipes being considered as blocks that you can build a room out of, in that you *have* to use the new type of block for it to be recognised as a wall. Though thinking about it this may end up being more trouble then it is worth, as I can't think of any blocks that aren't considered to be a wall, and changing pipes to an object instead would cause its own problems.
Dennis Scholz: if you would like examples of this, an AMAZING building game called from the depths, who also use unity have this type of block for exhausting fumes outside of the main body of ships and planes.
This has been implemented in Update 14, in the form of pipes being placable within building blocks.