Using Wired Motion Sensors on Elk M1 Gold to trigger lights on/off.

If I had $1 for every time my kids left their bedroom/bathroom/closet light on I'd be a millionaire!
 
I'm about to build a new home and considering purchasing the ELK M1 Gold and HomeSeer for HA.  If I hardwire most rooms with motion sensors can HomeSeer (via the Elk plug-in) "see" that something has entered the room and turn on the light - and stay on until no motion is detected for x minutes?  Is there a better, more reliable setup?
 
I could double-purpose the hardwired motion sensors to act as a form of lighting control (via HomeSeer or other) and alarm system (Elk) - at least that's what I'm thinking...  appreciate your wisdom/advice!

You don't want to dual purpose the motion detectors, you won't be happy with the results.
Motion detectors for security purposes are intentionally less sensitive than those for automation.
You don't want fale alarms with the security sensors so they need several "hits" to validate a detection.
You don't want to miss the slightest movement with automation sensors so they detect with a single pulse or two.
This puts the sensors at cross purposes if you try to use a single sensor for both purposes.

Security sensors are "motion sensors".
Automation sensors are "occupancy sensors".
Some occupancy sensors have dual tech and include microphones so even if there is no movement, like someone sitting at a desk or watching TV, the audio sensor will still detect presence.

Your general logic is sound.
Placement of the sensors can be tricky sometimes.
You don't want the light to go on if someone walks past the room but doesn't enter.
I use an IR barrier across the doorway to turn the light on and a ceiling mounted occupancy sensor to turn them off.
The barrier is about 3 feet above the floor so pets can't set it off either.

Some smart light switches have internal timers as well.
So they turn off after a predetermined time after turning on.
That can be used as a failsafe if the occupancy sensors don't send the command, or in areas like crawlspaces and attics where you don't really need the full set up.

Thx Desert_AIP for you comments.  
 
Q1)  If motion sensors are hardwired to the Elk M1 then what would an occupancy sensor be wired to (e.g. light switch, home run to closet and then controlled via HomeSeer or other) and how do you control/automate how/when/for how long the light should remain on?
Q2)  Can HomeSeer see all motion/alarm events that occur in Elk?  If so, could occupancy sensors be hardwired to the Elk (seems appropriate) and just use HomeSeer to monitor and determine when to turn on the light?

ccmichaelson said:

Q2)  Can HomeSeer see all motion/alarm events that occur in Elk?  If so, could occupancy sensors be hardwired to the Elk (seems appropriate) and just use HomeSeer to monitor and determine when to turn on the light?

Click to expand...

 
Yes and yes. You can also program Elk to do simple timed events based on the occupancy.

Yep, You just set up the zones differently for different functions.

Can anyone recommend a hardwired occupancy sensor compatible with the Elk M1 - or perhaps they all do...  I'm a noob!

Here is one:
 
http://www.sensorswitch.com/OnlineCatalog.aspx?sn=CMR%209

I've done this - and I've also even incorporated a W800RF32 so I can use cheapo X10RF motion sensors (like 5 for $20) so I can use motion sensors around the house and X10RF keypads.   I've also used regular wireless door security sensors on some doors to kick lights on and off automatically.  The Elk is great for it.  Some people complain about delay but in my case it's been a non issue.

Here too utilize hardwired occupancy sensors plus motion sensors with the Leviton OPII panel and still utilize the X10/W800 combo wireless sensors / palm pads today.
 
Very simple lines of automation are written to Omnipro Panel. 
 
Think of the analogy of a human body reflex versus deliberate motion of your elbow.
 
You hit a spot on your elbow and it bounces.  It short circuits your brain in a way.
 
You move your elbow with a conscious effort that runs a longer path (in a literal sense). 
 
Homeseer can monitor the occupancy and do some higher level stuff with multi step interaction with other physically connected devices (to Homeseer).