Our chapter at the University of Southern California has (or had, as of 2006) a security guard with his own small office next to the front door. I recall that it seemed to be typical for most chapters at USC, but I don't remember if someone was there 24 hours a day or just certain times.

And as far as Alpha Phi, I would bet that it was dumb luck that someone wasn't around to answer the door, rather than any kind of training.

Many chapters have overnight security guards these days. Very common.

There is nothing that replaces physical security.

That said, in terms of key cards, I'm surprised that most houses aren't using more secure entry systems given the usage patterns.

The ideal scenario, IMO, would be something among the following:
1.) There's a keycard to access any door. There are no accessible ground-floor windows.
2.) An access log is kept, which can be cross-referenced to security feeds.
3.) Keycards can be individually disabled if lost/stolen.

This way, anytime there's an incident of unauthorized access, it'd be possible to trace who is responsible and address the issue. The same applies to doors that are left open, etc.

Where I went to college, the student ID doubled as an RFID keycard. It was both light and convenient.

Those are some of the reasons most places use the key cards. However, it is still encumbent on the members to secure their cards because:

1) They lose it but fail to tell anyone.
2) They hand it to their boyfriend to open the door why they get their stuff out of the car (I actually walked up on this one once!)
3) It doesn't take into account opening the door from the inside...

RE: the bolded. No ground floor windows - interesting design concept. And doors that are left open - how do you control for doors that are propped open from the inside or opened from the inside? Or do you think a keycard should be used to open any door in either direction (ingress and egress)?

What you are proposing sounds like a prison.

The human element is the bottom line, as Dee, Titchou, others and myself have stated.

I speak from experience when I say that technology is easily thwarted by members who take shortcuts (eg. propping the doors open).

A big problem when I was in school was women using key rings with the letters on them, and then losing your keys. Now someone has your key and an obvious indicator of where you live. The same would go for key cards, if you use an ID holder with letters on it, which were common in my day.

I remember a few years after I graduated girls being warned against this too...and this is in small town usa.

Of course there's the social aspect.

The idea is that if a door was propped open, you'd know when it was propped open so you can hold the person who propped it open accountable. That's what the security camera is for. The social policies of not holding doors open can then be effected.

Ground-floor windows: that's easily solved with a bug screen of some sort or windows that don't open wide enough for humans to fit through.

Ground floor windows need to be wired so if they are opened/broken an alarm goes off - I think that's pretty standard. That's what I had in my (personal) house.

That's what assumed excelblue meant when she said no accessible downstairs windows—windows that can't be opened, that are high enough off the ground they can't be reached from the ground, that have some kind of landscaping barrier in front of them, and/or that are wired for an alarm.

Ah but you don't want so much a of landscape barrier that someone can hide in them!

When I was in college, the dorm system transitioned from physical keys (every resident was issued two keys, one for the dorm building and one for his/her room) to card readers at each dorm entrance (you swiped your student ID to get in) and a physical key for your room.

FSILG (fraternity, sorority, and independent living group) houses typically had a combination lock to get into the house. Non-resident members were given the combination, as committee meetings frequently took place in the house, and non-resident members were welcome to hang out in the house, participate in study groups, etc. Non-members had to ring the bell or knock, and explain to the person who answered the door whom they were there to visit and why.

In all cases, we were warned about "ghosting" (you swipe your keycard and someone you don't know follows you in).

True.

Two years ago, we went to fingerprint entries and we have security cameras covering all entries as well as perimeter shots of the house. We had fobs before but girls would lose keys with the green letters on them. It was scary.