Dunno much about residential automation but I do know industrial automation. You do not want to mix the two together. Some things to avoid are florescent ballasts, dimmer switches, motors ... etc. Analog signals can be skewed by proximity to these devices.
Discretes are less affected. May want to cover your *$$ by completing the job and getting the inspection signed off before allowing any changes to be done by this guy.
A few photos of potential problem areas before the changes may also cover you.

While I don't have any and don't want any automation in my home, it is coming and within the next 5 years it will be flooding the market. The cost of equipment is going down and will decrease even faster due to economies of scale in the near future. Appliances are being designed as we speak to have embedded operating systems. This will not reduce the need for sparkies, in all probability increase the workload and for those who want to enhance their skillsets will open up to a market that will blow wide open. The impact will be as great as personal computers did for workplaces. (Remember the promises of paperless offices <grin> )

Apologizing for getting on my soapbox. I'm in the middle of seeing some unbelievable products being released by my company right now. Small, cheap and powerful.

[This message has been edited by Currently (edited 06-08-2002).]