tankless water heater - install before kitchen remodel or after
Our home is a 1 story 1800 sq ft older home with a pier and beam foundation that was built in 1935 in Houston, TX. There has been a lot of work done - foundation, electrical, new sewer line, hardie board siding, A.C. ducts replaced, and other mainly exterior stuff. The interior looks pretty bad. A contractor will soon be starting on our hall bath and as part of the job, he will be replacing galvanized and pvc with copper. We hoped we would follow this job with the master bathroom remodel but after an inspection, we are wondering whether we should address the galvanized pipe issues first. We have lots of galvanized pipe including a bunch in the attic where the hot water heater is currently installed.
My question mainly concerns the sequence of work that needs to be done. We don't want to have it all done at once. Hoping to split into tasks but this is what makes things difficult.
I hope to interview a plumber with my questions but I'm concerned that it will be in his interests to do the whole job at once. I would like to know what I would be losing (or gaining) by splitting the job into separate parts and I would also like to know what sequence to do the parts.
1. If we want a tankless water heater (gas), should we have it installed before the master bathroom and kitchen remodel? Can this task be separated out from the other jobs for the other areas (see list below)? If so, should the tankless water heater come first and then master bathroom and then kitchen? (Our gas pipe has the required diameter for most of the run but underneath kitchen, it needs "enhancement" I think, plumber will hopefully confirm.
List of jobs to be done (none of these tasks will be DIY):
1.) Move gas hot water heater out of the attic and replace with an external tankless water heater downstairs on side of house outside kitchen.
2.) We currently have a major hall bath remodel coming up soon that includes having all the galvanized (and PVC) in the hall bath replaced with copper, at least in this bathroom.
Washer and Dry are also being moved out of the kitchen and installed in the hallway outside the hall bath. Copper plumbing will be used with washer/dryer also.
3.) We had hoped to move next to the master bath remodel where a small shower will be replaced with a tub. And galvanized replaced with copper.
4.) Master bath is adjacent to kitchen which is also scheduled for total demo and remodel. Also have galvanized in kitchen to be replaced with copper plus a small sink added and misc other plumbing tasks standard for kitchen remodels. Will not be using gas stove.
5.) We also hope to have a new roof installed.
6.) Also convert current vented attic to unvented/conditioned attic - using spray foam.
7.) Floors need refinishing and lots of painting and bookcases installed in living room and study.
Any feedback would be greatly appreciated.