Bathroom renovation and future bath?

[James-Fixit]

Thanks for all the great information. I’ve been searching the forum for years during my various bathroom renovations. I am preparing for bathroom renovation number three and this one will likely be the most complicated, so I thought I’d ask for help in planning before I begin. My home is a 1950s era colonial and upstairs we have a small (7x5) bathroom – see image for existing setup. I want to update it where we reduce the size of the window from 2x3 to 2x3, remove the tub and insert a shower (with a small seat), move from a pedestal sink to a small (24”) vanity, either switch the door hinge side or install a sliding door, and upgrade the cold water from ½” to ¾”.

https://photos.app.goo.gl/Mbr5vDDfUgqvAVsl2

I am going to have to reorient all the plumbing – a big task. See the diagram for the planned upgrade. (I am not going to know for sure what the final outcome will look like until I complete all the demolition, but this is the plan until it changes.)



The most challenging part of this project is that in three years we plan to add an addition that will include a small master bath (9x8). When I renovate this bathroom, I want to plumb it such that I can connect to the existing plumbing. The future addition bathroom will either be catty-cornered (preferred) or share a wall with the existing bathroom. I plan to upgrade the cold water pipe to 3/4” and do the same for the hot water – if possible during this renovation. If I can’t upgrade the hot water I was planning to install an instant heat hot water heater in the new bathroom and use the 3/4” cold supply.

Is it possible to plan for the addition and plumb the bathroom to allow for the future room? Is there anything special I have to consider (adding a secondary vent in the new addition)?

 

[WorthFlorida]

I cannot answer all your questions but this project you will need a permit & an inspection since your future expansion will require a building permit. If something is done wrong now and it is not noticed until the future bath is installed it can cost allot more.

Going up to a 3/4 inch hot water line will take a lot more of running water before it gets hot. With an old house I'm guessing that you may have galvanized pipe and the water flow is being restricted due to corrosion inside the pipe. Is it perhaps you're on a well? If the distance is quite long from the water heater to the bathroom 1/2" would save a lot of water. A 1/2" pipe is .0102 gals per foot and a 3/4" is .0230 gals per foot, more than twice the amount. http://www.rhomarwater.com/calculators/pipe-volume-calculator

I at one time had a small bath, shower only, and I had the door swing out into the master bedroom. It worked great. pocket doors are a pain to pull and push to operate. They only look good on TV.

I'm not a plumber but as far as trying to plan for the future bath the waste lines may be something you cannot do. Water lines it is no big deal to tee off and stub the pipe for a future connect. Venting the new bath it would be just get a pipe up the wall into the attic to add a vent at the roof or tie into an existing one. But to put in waste tee's without able to come up to a floor level may not be permitted. Waste can sit inside the plumbing and cause other issues. This would have to be answered buy plumber in your area.