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Critique my sensor choices/placement


I'm designing my security system layout (and whole house audio and home theater and...) for my house currently under construction. I'll probably have several more threads regarding this, but I'm going to try and keep my topics focused.

So this question is about my choice and placement of motion and glass break sensors...

Please refer to attached house layouts with proposed sensor locations (this in addition to contacts on all exterior doors/windows)

I have a 70 lb dog, so a pet immune PIR was a must. For this I am planning on the Bosch DS835i. For the Glass Break Detectors, I'm probably going with the Sentrol 5820, but might try and save a few bucks with the 5812-RND if the wife is OK with the aesthetics.

The PIR's will be mounted ~7.5-8ft, and all GBD's will be in the ceiling, except possibly for the one in the 2nd floor hall which might go in the wall.

Any concerns with this layout/sensor choice or suggestions for improvement?

Thanks for your help!


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I would move the motion detector on top of the stairs to the master bedroom. It seems you have two entry points there, so that would be the room where you would first want motion to be detected on a (second story) break in.

Plus you already have one downstairs (for the staircase entrance) so the staircase should be protected on a break in from the ground floor.

Plus, I have no idea how expensive they are, but since you are going through all the trouble putting in those ceiling glass breaks, you may want to look into a combination ceiling glass break/motion detector sensor. Of course I don't know if they make pet immune ones with this combination. I just remember seeing these and was thinking how cool it would be to have this combo in every room.

I don't have ANY experience with them though. ;)


Thanks for the response.

You've got a good point on the 2nd floor PIR. My first thought is to add an additional PIR to cover this situation. You're right that the stairway is covered downstairs, but I have a semi-irrational feeling that the path from the deck to the kids rooms needs to be protected/monitored. Now I suppose we're not going to have the PIR's armed when anyone's home, but possibly set to some sort of voice alert or something to know if intruder is entering or kids are leaving?? Does the hallway PIR have any value from a HA perspective? At this point another $50 or so won't kill me.

Regarding glass breaks, do you think I'm going overboard? I just put them in pretty much every room. On further thought, placement in 2nd story rooms not adjacent to a deck (like kid's rooms) seems unnecessary, but I'd be interested to hear others thoughts on this.

As I understand it, the ceiling-mount PIR's are not pet immune, but the combo PIR/GBD might be a good option for others.

Thanks for your input!


For another $50 just put the motion sensor in both places. You can always bypass the motion sensors in "stay" mode and just have the voice announcements for the motion detectors if you want.

I think glass brks in every room is a good thing, if you can afford them and have the wire/zones for them as well. I would also put motion detectors in every room if I could because you could do things like automate the lighting with them.

If you do something like announce when kids are leaving, make sure you have a keypad upstairs so they can disarm the system in the morning!


Senior Member
I thought you would have had more coverage on the first floor for motion. I am not up to that yet (and clearly no expert), but I had intended having motion detectors in all first floor rooms, including those without entrance/exits to the outside even though the windows will be alarmed.

Is this not a typical practice?

I like those glass break detectors I just haven't thought of a good installation point for them (ceiling is not easy, would have to open it up and do some drilling) or an appropriate alternative. I don't think the wife would appreciate them in the walls either.


Hey Mike. I purchased THESE Sentrol glass breaks from Martin (to the right of the keypad) and they aren't to noticable as they mount flush with the drywall (just make sure you have enough room behind the drywall for them to mount in).


Senior Member
Hmm, thanks. I wonder how the wife will like that. I am guessing they need line of sight to the window, right (I am wondering if I can place them out of the way).

Now a combination motion detector with glass break sensor would make sense... I was looking at Optex before and hadn't seen anything. I was going to look at the Bosch line mentioned in this thread as well.

I guess you can't hide these in a speaker grill either like some IR sensors, or can you? I have speakers in the walls in the main rooms and this would help, although that might not be good for the sensor when the speakers are on.

I need to do some further research on what is out there, but I am getting close on this one.


Active Member
What is your objective? If protecting the property is your main objective, then all the sensors inside the house will help you to be notified if somebody breaks in. The intruder will take a few things and and run.

If protecting the life of your family, specially when your are out is the key priority, the you must not forget the protection of the perimeter of your lot (zone A*) and the perimeter of the house (zone B*).

*This is OPTEX nomenclature. Do not confuse these zones with the enumerated sensors assigned in the alarm panel, also called zones.

See the first page of this sensor specification by OPTEX for small diagrams illustrating the zones.

Zone A - Covered by IR beams and exterior PIRs (specially twin technology including microwave/PIR to prevent false alarms). Depending on the probability of having false alarms caused by pets or service people (landscaping, swiming pool cleaning), you will not trigger alarms. Instead they will notify you about the possible presence of intruders via voice, email or phone. You can also turn on security lights or turn on the sprinklers.

Zone B - Covers close perimeter of your house. Not only via window/door sensors, but better yet using sensors like IR beams or a device like the OPTEX BX-80N that would notify your if a person is peering at a window or trying to open a window or door. This zone would trigger an alarm at all times. I would say that the GBD would fall in this category because they focus in protecting the perimeter.

Zone C - Cover the interior of your house. Would trigger alarm only if the system is activated in AWAY mode, so they do not protect the life of your family. In this area fall all interior PIR and IR beams, in addition to any imaginable sensor, like interior door sensor. When you have big pets most experts recommend against using PIR sensors, even when they argue to be PET inmune. If you want to use them you should use them in their PET alley form (high enough). But even better for a new construction are the IR beams at strategic points. If properly located and hidden you will detect the presence of an intruder without ever being triggered by a pet. You might consider the OPTEX AX-100 SR, but I prefer the TAKEX series of minuature photoelectric beams like the PB-10NS. The TAKEX can be hidden in your walls and only need a hole of about 3/4 to see thru. Another alternative here is the Visonic miniature detector family (PIR).

Other important reason for Zone C is automation. You can always make your house make convenient actions for you depending on where you are.


Senior Member
That is a great summary. Thanks. That really describes it well.

On the pet immune that was referenced, is that only for BIG dogs, or in general? I, for example have 2 dogs (20 and 30lbs) should I expect trouble?

I was going to buy one of whatever I selected and test it when I got to that point.

The zone B items for the windows look pretty apparent, I pity the would be thief on page 1 :D That may be part of their deterrent however...