You mentioned in your post that the contractor wasn't to thrilled with your input you didn't state it was a general contractor and the way it sounds now is coming with a bid on the job sounds like no prints are drawn up and he is just getting a feel for the total cost of project. This is my suggedstion ask for a kitchen lay out printy and draw in what you feel is needed and a total break down of materials with the statement of being comprable within their codes. So the general can submit to elecectrical bids for the cost of this project. My opinion is to stay out of it if you put your 2 cents into it which you stated your not the one to pay this addition your sister is then if you make alot of change orders could be higher cost to your sister. Also you have iritated this general as you said in your post and any more input could have them pull off the job and your sister hanging in a dilema without occupancy permit and this general might spread the word out about this job to avoid, so she might have to hire the carpenters from the T.V. Show Green Acres and they will probably bring Arnold with them. And it also sounds that you have a good relationship now but what if you go to far with these contractors and they say more and more money because Brother 3000 miles away costed you?