Trev, I'm sure you can lien a church ... but enforcing the lien is an issue. The lien is only a problem at sale time - and churches don't sell very often.
Likewise, churches typically don't use much in the way of credit- and most suppliers watch then like hawks already.
Only time to ever use a sq ft rate is when somebody asks you,"Off the top of your head, give me a number for this building" And when you are to lazy to bid the job and dont want it anyway
I would never use square footage to bid a job. There are too many varibles involved. In my eyes that is just being lazy and when a business is dependent on it bids, that is a lazy business plan. Square footage at best in my eyes only works to ballpark a conceptual project simply because there is nothing else to use. Garbage in, garbage out.