Do I need to change any piping when replacing a laundry room with a bathroom

You should really post this under plumbing, when you do, please give more info, such as what fixtures you are going to have in the new bathroom. Toilet, sink, tub/shower. Also what size drains and water supplies do you currently have in laundry room. I'm sure there is going to be need of serious plumbing changes. Like I said, please post this under plumbing, and we will try to help you out.

Do I need to change any piping when replacing a laundry room with a bathroom

We need more information. Is there a stack or main near by that you can connect into? In addition to the water piping this is how a typical bathroom is roughed in. Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim. Good luck and thank you for rating my answer. Tom