A kitchen or bathroom remodel is one of the few times a St. Louis homeowner can add water treatment without opening finished walls twice. Walls are open, cabinets are out, and the plumber is already on site. Deciding on treatment equipment before the new counters go in is usually easier than fitting it in later.
Decide what the treated water needs to serve
Before you plan any layout, decide which fixtures get treated. A kitchen sink filter for drinking and cooking water is a different job from a whole-house system, and a shower filter has its own purpose. Many homeowners in the city and the surrounding county focus first on drinking water, then decide separately about bathing water. Write down the fixtures you want treated, the ones that will stay on the untreated line, and any appliances such as a refrigerator or ice maker that need their own supply.
Get a baseline reading before demolition
Pull your most recent water quality report from your provider. If you are on a private well, schedule a test before any walls come down, because well water can vary more from one home to the next. Note hardness, chlorine taste or smell, iron staining, cloudiness, and any odor you have noticed at the tap. Those findings shape whether you need a sediment stage, a softener, a carbon stage, or a reverse osmosis unit. Reading the data before you shop keeps you from buying equipment based on a product page instead of your own water.
Plan the rough-in while walls are open
Rough-in is the stage where supply lines, drain lines, and electrical runs are placed inside open walls and under the floor. Ask your plumber to plan for the following:
- A dedicated cold supply line to the kitchen sink location, with room to route it behind the cabinet.
- A capped stub for a future refrigerator or ice maker line, so you do not have to cut into the finished wall later.
- Drain access that allows an air gap or a waste connection for reverse osmosis discharge.
- An outlet or junction box where a pump, UV unit, or electronic controller will need power.
- A route and floor space for a storage tank, if you choose one.
- Shutoff valves on each treated branch, so you can service equipment without shutting off the whole house.
Take photos of every stub and valve before the drywall or tile goes up. Those photos are useful years later when a filter needs service and no one remembers where the line runs.
Check cabinet and sink space carefully
Under-sink space is tight, especially in older St. Louis kitchens built around a standard plumbing layout. Measure the cabinet interior before you order equipment. Check the depth at the back wall where pipes bend, the width around the drain trap, and the clearance above the floor where a filter housing will sit. Equipment that fits a new cabinet may not fit an older base cabinet with a rear panel or a rolled drain pipe.
Plan the faucet too. A separate filtered water faucet needs deck space or a sink hole, so decide that before the countertop template is made. Changing the countertop plan after fabrication is expensive and frustrating.
Think through the bathroom and the main entry
In bathrooms, the choices are usually simpler. A shower filter addresses chlorine taste and odor, while hardness normally calls for a softener on the main line. If you are considering a whole-house system, the equipment usually sits near where the main water line enters the house, often in a basement or utility room. Make sure there is enough room to service it, and that a drain is close enough for any backwash or discharge. Many St. Louis basements are cramped, so plan the access path before the equipment is delivered.
Ask about permits and inspections
Plumbing and electrical work in St. Louis usually requires permits and inspections. Rules can differ depending on whether your home is inside city limits or under a county jurisdiction, so confirm with the building department that covers your address before work begins. Ask whether an air gap, a backflow device, or a specific drain connection is required, and ask whether the permit covers the water treatment work as well as the remodel.
Settle these questions before the crew arrives
- Which fixtures will be treated, and which will stay on untreated water?
- Where will the equipment sit, and how will a technician reach it for service?
- Is there a drain available for reverse osmosis discharge or backwash?
- Are outlets planned where pumps, UV units, or controllers need power?
- Is there a shutoff for each treated branch, and is it reachable?
- Does the permit cover all of the water work in the project?
Test again after the finish work
Once the remodel is complete, test the water again. New fixtures, new pipe sections, and flushing during construction can change readings for a short time. A second test gives you a clean baseline for the finished system and a record to compare against when filters need changing. Keep the rough-in photos, the permit paperwork, and the test results together in one place. A remodel is one of the easiest times to set up water treatment properly, and a little planning now makes the equipment easier to live with for years.