dmpoole said:
....
I like to think that when the houses are being cased that the scumbag looks at my house and thinks "Too much trouble".
It's all a question of balancing effort and expense of a security system, against the determination and professionalism of those trying to gain access.
And you're right - unless you are the specific target of someone after something specific (and if you are, your security will probably have to be quite a lot more comprehensive, and expensive, than any home alarm system), making your place less attractive to the opportunist is a highly cost-effective method of improving home security, and the kind of obvious visible deterrents you've mentioned are exactly the kind of thing that makes that opportunist go someplace easier and less risky.
The first thing to do when designing any home security system is to take a good step back, and try to assess the security risks from the outside. Check out the strength of doors and windows, visibility from the street, whether passers-by can see your fancy new 50" plasma TV from the street, whether ladders are locked away or chained down, whether front door and windows are screened from clear visibility from the road (because if they are, an opportunist can work without being seen), consider adding trellace to back fences, consider unpleasant, thorny bushes for the border. You can't add broken glass to the top of your fence (without laying yourself open to prosecution), but you
can put in nasty thorn bushes that would shred any intruder trying to get through them.
The most valuable single item in anti-intruder defense is the few pounds of grey stuff between your ears. So many people think that if they just stick an alarm up, it'll do the trick. The money MIGHT be better spent on shrubs, ladder chains, net curtains, anti-climb paint, clippers to trim back front foliage that gives an intruder something to hide behind, and so on.
But, dmpoole, it certainly looks like you've thought this through carefully.