We have the same entrances as you it sounds like. Our dog goes in and out of all 3 doors! It hasn't been an issue as we are in a rural area, there really is no "perfect" entry. I guess the entry from the garage into the house (hallway looking towards kitchen) is the most appropriate for a dog. We have a runner on the floor in front of the door so we do encourage the dog to come through there in bad weather. We considered a "dog door" in the beginning but couldn't figure out a good place for it.

We currently have a pet door into the laundry room and will have the same on our build. Problem is that we have big dogs and it's a security issue although if the bad guys want in bad enough they will. We are lucky to be in an area currently and at our build where that isn't a concern. Simple rugs that dont have the rubber backing work well with us as they are easily shaked out and thrown in the washer now and then. The rubber backed rugs seem to fall apart quickly and you cant throw them in the dryer. Here's a link to pet doors where we got ours including patio door pet doors.

Here is a link that might be useful: pet doors

We have a rectangular back hall (laundry at one end, powder room and large closet at the other end). Opposite one another on the long walls are doors to kitchen and garage. Door opposite laundry end goes to back yard. This is the door our dog uses. When he comes in I put him in the laundry tub to wash paws.

We have a peke that is nearly 14, and is used to a doggie door and invisible fence. Currently have a doggie door from the laundry room to the garage, and another from the garage out to the back yard. Works great. But she is a tiny thing, and not prone to digging, or getting dirty. She's pretty easy. We may do the same set up in the new house, assuming she is still with us.

I suggest having a "doggie shower" in the laundry room with a dog door. A simple floor drain and a hand held shower make short work of muddy paws. And if you have a Dutch door to the laundry room, it serves to contain the mess that you can't immediately supervise, like if she goes out at night after a skunk!

Interesting post! Actually, we've been thinking about some features we want in a new build/renovation. One thing we are definitely going to do is have a "dedicated" door to a penned-in dog area. Its only purpose will be to let the doggies out to their dog area (fenced in). They are beagles so can't be trusted off leash unless they are in a secure area.

It's a good deal for us because all the other doors would not go directly to the doggie pen area. We would be able to just open the door, let them out, and let them back in once they do their business.

I don't think it's an extravagance at all. Putting a door in should be fairly cheap in the grand scheme of things.