You can't have, "true security" if you leave the windows and doors open while you're not home. But I guess you could always put bars on the openings.
Ron.

Those screens will keep out anyone who doesn't have a box cutter. Maybe what you need is a motion detector alarm.

One thought is a good quality wood French sliding glass door by someone like Andersen. Since you don't have to accommodate door swing with one, they work quite well to conserve space. And I find them attractive. They are also easier to use with screens than the classic swinging French door.

As far as ventilation goes, I suppose that you could put a wood dowel or rod in the track to prevent the door from being opened far enough for someone to get in, and still allow ventilation. Or find another source of ventilation that doesn't compromise your security as much as using doors.

There is also the classic Atrium-style door, which is a double French door where only one side is openable. This means that you only need to plan for one door swing space. The drawbacks are that ventilation is again an issue...These doors are typically not secure when used for ventilation.

-Roger