New Plumbing for Alliance Rentals, Duplex Conversions and Added Units

What Changes When a House Becomes Two Units

A single-family home has one kitchen, one main bath and one water heater feeding everything. Splitting it creates a second set of fixtures that all need drains, vents and supply lines, often on a floor that was never plumbed for a kitchen. Before work starts, we look at where the new kitchen and bath can share a wall or chase with the existing ones, because stacking wet rooms is the simplest way to keep drains short and costs reasonable.

The other early question is how independent each unit should be. Separate shutoffs are a must. Separate water heaters are often worth it. A separate water service and meter is a bigger project and depends on the utility, but it is worth discussing if you plan to bill tenants for water.

Building New Lines for Tenant Use

Rental plumbing gets harder use than owner-occupied plumbing, and repairs are usually requested at the worst possible time. A few choices made during rough-in pay for themselves:

• Accessible shutoff valves for each unit and each fixture, so one leak does not shut down the whole building
• Cleanouts placed where they can actually be reached, not buried behind a finished wall
• Full-size drain lines for kitchens, since grease and food scraps are the most common tenant clog
• Water hammer arrestors at washer boxes and quick-closing valves
• Drain pans and leak sensors under upstairs washers and water heaters
• Supply piping kept out of exterior walls wherever the layout allows

One water heater or two?

A shared tank is cheaper to install but can leave the second tenant with cold showers. Giving each unit its own heater evens out hot water supply and makes it simpler to divide gas or electric costs. We help you weigh the space, venting and fuel options on site, and can install gas water heaters where a gas line is available.

Inspections and Code Issues on Older Rentals

Adding a dwelling unit usually triggers permits and inspections, and the inspector may look beyond the new work. Missing vents, S-traps, illegal drain connections or deteriorated pipe found during the job may need correcting before sign-off. We flag those issues during the estimate so they are part of the plan instead of a surprise. If an inspection has already turned up problems, our plumbing code violation repair service can bring the existing system up to standard.

New rough-in is tested and inspected before walls close, and the final inspection follows once fixtures are set and running.

Planning Around Tenants and Turnovers

If one unit is occupied while the other is being built out, we plan shutdowns in advance and keep them short. Tie-ins to the main stack and water service happen in a single planned window where possible. For owners with several Alliance properties, scheduling new installations between leases avoids disrupting anyone.

Some landlords also put their buildings on our plumbing maintenance agreement, which includes an annual inspection and priority service and is transferable if a property is sold.