OK, so this question is rearing its head again so I figured I’d try and put a post together with the help of everyone else to show the state of play in the UK.
I know there are some USA DTH’s that use Vista? or something to integrate, but I’m not sure what works in the UK.
It’s worth mentioning that some home insurers will only give you a discount for a professionally installed, accredited alarm. However, if you mention you have an alarm, regardless of its type, and then have a break in and you didn’t set your alarm, you may find your insurance is void!
Thanks @PailOckenden
Traditional Smart Alarm Systems
These alarm systems are of the more traditional variety. You know the kind - PIRs in the corner of rooms, window and door sensors, break glass sensors, control panels and most importantly and exterior bell box. They also have built in remote control or Home Automation connection
Texecom Premier Elite
http://www.texe.com/uk/technology/connect/
One of the most popular alarms on the market, and used across business and houses alike. This is a traditional home alarm, so you have a pin pad, window, door sensors etc and an exterior bell, as well as a control panel which is the brains of the house.
It does currently have a WiFi module that allows for remote control, however it does not currently integrate with Z-Wave devices. Texecom are working on Version 4 of their software which will include Texecom Connect which will work similar to SmartThings, but also have an API for 3rd party connection.
Risco Lightsys 2
http://www.riscogroup.com/uk/products/solution/724
Risco Lightsys 2 is again a traditional style alarm. They don’t currently have a roadmap for Smart Home integration, however they do offer their own remote control system
Smart Only Alarm Systems
I call these Smart Only Alarms as they’re not really the traditional kind everyone is used to. These don’t normally have exterior bell boxes or control panels, but more a hub. You might find that your home insurance does not class these as alarms for insurance purposes
MyFox
A relatively new company but only includes cameras, motion sensors, break in sensors and an interior alarm. An exterior siren is coming later this year. No idea if this has an API for 3rd party connection
Yale Smart Home
Lots of options available here. Doesn’t seem to connect to any 3rd parties and relies entirely on Yale keeping their services alive.
Swann One
http://www.swannone.com/gb/products/kits/
I haven’t really got much information on this other than that I’ve heard of it. From what I can tell, its an enclosed system with no 3rd party access. It also relies on Swanns servers being maintained and offers PAYG plans
SmartThings
SmartThings has a built in system, and there are some SmartApps out there that can also act as an alarm. I currently use this as a temporary solution until I find a traditional smart alarm. Unfortunately, I can’t rely on SmartThings as an alarm - it’s far too temperamental.