Home construction – is this normal? (w/ pics)

Factual Questions
1

Sorry for the vague title, but I wasn’t sure how to coherently phrase this.

A couple weeks ago we were having some electrical work done. In fishing wires up through an exterior basement wall, the electricians moved some insulation out of the way of the ceiling. In doing so, they uncovered a bunch of mouse droppings in the insulation and exposed ground (this is the bit that’s hard to describe). That is, the frame is sitting on the foundation, overhangs it a bit, and is open at the bottom. They were rather adamant that this was a construction problem and I needed to call a carpenter to take care of it.

I have limited construction experience (mainly grunt work for Habitat for Humanity), so don’t know if what they were saying is true or not, if my house is about to collapse, if it’s a portal for Cthulhu, or what to do about it. Or maybe it’s normal and they wanted to get some carpentry work for a friend. But winter is coming, and we do tend to get more mice in colder weather, so I’d like to figure out if I should be doing something.

If it needs fixing, do I call in any old carpenter or do I need to look for someone more specialized in home building? Is this something that should have been discovered during the pre-sales inspection? If the builder left out something important but hidden, is it likely I can get him to fix it?

If it makes a difference, this is an exterior basement wall of a two-story house. The oil furnace is against the wall, the fireplace is above.

Hoping this helps, here are some pictures: [ul]
[li]the wall[/li][li] top of wall[/li][li] looking down I[/li][li] looking left[/li][li] looking down II[/li][li] looking down III[/li][li] looking down IV[/ul][/li]
Thanks,

Rhythm

2

IANAE, but I would expect that to be closed, not open.

Am I looking at this right?



            |  <--Your house
            |
_________   |  <-- Mouse Entrance
     |
     |----------------------------------------------Ground Level
     |
     |<-- Your foundation
     |
     |
_____|

IIRC, my parents had a problem where the board that’s supposed to be at your “mouse entrance” was missing (due to rot or persistent rodents). They filled it back in… no more mice.

3

I’ve never seen a frame overhanging a foundation before. It looks like whoever built the house wanted an extra foot, or so, of house but only discovered this after the foundation was poured. But why does it look like the very outside wall is also poured concrete? There’s something my brain isn’t grasping here.

What is the outside wall made of? ETA: Mine’s a top view.



  |
  V
  ?    | |
  ? =========== joist
  ?    | |
  ? ===========
  ?    | |
  ? ===========
  ?    | |
  ? ===========
  ?    | |
        f
        o
        u
        n
        d
        a
        t
        i
        o
        n
4

To me it looks like a portion of the above room has been cantilevered. That’s not an issue if structural calcs has been done.

The work wasn’t finished off properly. One way would be to nail/screw cladding to the underside of the joists.