If I were laying out a new build—or doing a major remodel—these three decisions would be baked in from day one: a whole‑home water filtration system, an electrical outlet at every toilet for a bidet seat or integrated bidet, and a tankless‑ready mechanical area with the right gas, venting, and power. In this post, I’ll walk you through why these are “must haves,” how to design them right from the start, and what to expect on installation and upkeep.
Non‑Negotiable #1: Whole‑Home Water Filtration
If you want longevity, health, and efficiency from your plumbing system, filtration belongs at the very front door of your water supply. Municipal water is treated to keep you safe, but the chlorine (and sometimes chloramine) used for disinfection is tough on your plumbing components and isn’t everyone’s favorite to drink, cook with, or bathe in.
Why Filtration Comes First
- Protect your plumbing. Chlorine is notorious for drying out rubber and neoprene. Toilet flappers, faucet cartridges, o‑rings, dishwasher and washing machine hoses—the more chlorine exposure, the faster they wear. I’ve seen homes needing new flappers in under a year because the water chemistry was harsh on soft parts.
- Better taste and fewer odors. Activated carbon takes out chlorine taste and smell. Once you’ve had filtered water at every tap and shower, it’s hard to go back.
- Whole‑body exposure matters. Your skin is your largest organ. When you shower or bathe, you’re not just smelling chlorine—you’re in it. Reducing residual disinfectant at the point of entry lowers overall exposure.
Common Filtration Building Blocks
A good whole‑home setup is modular. Think of it like a filter “train” sized for your house:
- Sediment prefilter (spin‑down or cartridge): Catches sand, grit, and rust that would otherwise load up your carbon media and clog aerators. These are inexpensive and easy to service.
- Activated carbon (or catalytic carbon) tank: The workhorse for chlorine removal and taste/odor improvement. Catalytic carbon performs better against chloramine if your utility uses it.
- Optional: scale control or softener: If you have hard water, add a softener or a scale‑inhibiting system after carbon. This protects your tankless water heater, shower glass, and fixtures.
- Optional: UV disinfection: On well water or in rural areas, a UV unit after filtration adds microbiological protection.
- Point‑of‑use polishers: In kitchens, an under‑sink RO system gives you ultra‑clean water for drinking and cooking. Consider this the finishing touch, not the whole strategy.
Sizing, Location, and Plumbing Details
- Size for your peak flow. A typical single‑family home should size the carbon tank for the maximum gallons‑per‑minute the house can demand (showers + laundry + kitchen). If the tank is undersized, you’ll feel pressure drop and reduce contact time (which reduces performance).
- Place it right after the main shutoff. Ideal order: meter → main shutoff → pressure regulator (if needed) → sediment → carbon → softener/scale control → house manifold. Include a hose bib or sampling valve after the filters to test water and flush lines.
- Add a bypass. A three‑valve bypass lets you service filters without shutting down the house.
- Consider drain and electrical. Backwashing carbon tanks and softeners need a drain. UV units and some automatics need a 120V outlet.
Maintenance Made Easy
- Set reminders. Spin‑down screens may need monthly rinses. Cartridges are often 6–12 months. Carbon media tanks typically regenerate or backwash automatically; softeners need salt. UV bulbs are replaced annually.
- Test, don’t guess. Keep a simple chlorine test kit on hand. When you see breakthroughs at fixtures, it’s time to service upstream.
Quick Build‑Sheet for the GC
- Rough‑in a 36–48 inch clear wall space near the water entry.
- Provide a floor drain or dedicated standpipe for backwash discharge.
- Install unions and isolation valves on every component.
- Confirm PRV setpoint ~60 psi (or as appropriate) to protect filters and fixtures.
Non‑Negotiable #2: An Electrical Outlet at Every Toilet (for a Bidet Seat or Integrated Bidet)
If you’re building new, do yourself a favor: put a GFCI‑protected receptacle within cord length of every toilet. Electrified bidet seats and integrated bidet toilets aren’t a luxury gimmick anymore—they’re a genuine upgrade in cleanliness, comfort, and even plumbing performance (less toilet paper means fewer clogs and happier septic systems).
Why Power Near the Bowl Changes Everything
- Hygiene and comfort. Warm‑water cleansing, heated seats, and gentle drying make you cleaner and more comfortable than paper alone. Once you switch, you’ll wonder why you waited.
- Lower paper usage. Families routinely report major reductions in toilet paper consumption, saving money and the occasional call to a plumber for a paper‑induced blockage.
- Accessibility. For people with mobility issues or certain health conditions, a powered seat can be a game‑changer.
Electrical Basics (Do It Right the First Time)
- GFCI protection is non‑negotiable. Bathrooms require it. Whether you use a GFCI receptacle or a GFCI breaker, the outlet serving the bidet must be protected.
- Circuit sizing. Many seats are fine on a 15A circuit; some high‑end units recommend (or require) a dedicated 15–20A circuit. In new construction, a dedicated circuit per bathroom or per bidet location is smart design.
- AFCI and tamper‑resistant. Many jurisdictions require AFCI protection on residential receptacle circuits and tamper‑resistant devices. Plan for it.
- Placement. Most cords are ~3–4 feet. Place the receptacle on the same wall as the toilet, 12–18 inches above the finished floor, laterally within reach of the tank side (avoid trailing cords across walkways).
- Don’t daisy‑chain off lighting. While you’ll hear stories about tying into a light switch, best practice is to pull from a properly sized bathroom receptacle circuit that can handle the load.
Plumbing Considerations for a Clean Install
- Quality shutoff and hose. Upgrade the angle stop to a quarter‑turn ball valve and use a braided stainless supply. Many seats include a T‑adapter; avoid plastic valves.
- Backflow protection. Reputable products incorporate check valves. Make sure the seat or integrated toilet meets plumbing code.
- Bowl compatibility. Measure bolt spacing and choose elongated vs. round to match the bowl. If you’re picking new toilets, select models with robust seat mounting areas and easy access to bolts.
Remodel vs. New Build
- New build: Run power and GFCI during rough‑in. It costs pennies on the dollar now.
- Remodel: If opening walls is painful, Wiremold‑style surface raceways can be an elegant retrofit, or a nearby vanity circuit can sometimes be extended legally by a licensed electrician.
Mini‑Checklist for the Bidet‑Ready Bathroom
- GFCI/AFCI protected receptacle within 3–4 feet of toilet
- 15–20A capacity available; dedicated if recommended by the manufacturer
- Quarter‑turn shutoff valve and braided supply
- Clear path for cord and hose—no trip hazards
Non‑Negotiable #3: Design for a Tankless Water Heater
Tankless water heaters shine in new construction when you plan for them from the start. You’ll get efficient, on‑demand hot water, reclaim floor space, and avoid the biggest retrofit headache—undersized gas lines.
Why Tankless Loves New Builds
- Efficiency and endless hot water. Modern condensing units are highly efficient and provide continuous hot water as long as you need it.
- Smaller footprint. Wall‑hung units free up mechanical room or garage space.
- Long‑term serviceability. With isolation valves and a flush kit, annual maintenance is straightforward. When replacement time comes years down the road, it’s a like‑for‑like swap.
Gas Sizing: The Make‑or‑Break Detail
Traditional tank heaters typically pull 30,000–40,000 BTU/hr. A full‑size residential tankless can draw up to 199,000 BTU/hr. That’s not a typo—roughly five times the gas. If you don’t size for it, you’ll starve the appliance and everything else on the line.
Plan for:
- Larger trunk lines. Many homes need a 1″ or even 1‑1/4″ main gas trunk (depending on run length and total connected load), then reduce near branches. Don’t assume 3/4″ will cut it.
- Meter upgrade. Coordinate with the utility to ensure the meter can deliver the volume you need.
- High‑pressure option. In some designs, a 2‑psi service with point‑of‑use regulators allows smaller pipe diameters over long runs. This is common on larger homes and can be cost‑effective if designed at rough‑in.
Venting, Combustion Air, and Condensate
- Category and materials. Condensing tankless units typically use PVC/CPVC or polypropylene venting (follow the manufacturer). Maintain required clearances to windows, doors, and property lines.
- Combustion air. Direct‑vent models pull air from outdoors via a concentric or twin‑pipe setup—safer and more efficient than drawing room air.
- Condensate and neutralizer. Condensing units produce acidic condensate. Rough‑in a drain with a neutralizer kit, and slope the line properly. Where gravity isn’t possible, include a condensate pump.
Electrical and Freeze Protection
- Provide a dedicated 120V receptacle near the unit for ignition, controls, and freeze protection. This is also handy for flushing the heat exchanger with a pump.
- Service switch. A local disconnect or switch makes maintenance safer.
Recirculation: The Secret to Instant Hot
Long hot‑water waits for waste water, money, and patience. While you’re framing:
- Run a dedicated recirculation return line from the furthest fixture back to the mechanical room. Many tankless units include or accept a built‑in recirculation pump.
- Choose your control. Demand‑activated (push‑button or motion sensor), timer, temperature, or smart controls each have pros and cons. Demand‑based systems save energy by running only when you ask.
Water Quality and Scale Control
Tankless heat exchangers are sensitive to scale. If you’re in a hard‑water area:
- Pair the tankless with softening or anti‑scale treatment. Put it downstream of your carbon filtration.
- Install full isolation/flush valves. Annual flushing with a mild descaler keeps efficiency high and prevents premature failure.
Location, Noise, and Clearances
- Centralize the unit. Shorter hot‑water runs mean faster delivery and less heat loss.
- Consider the climate. Outdoor units are popular in mild regions, but indoor units in a garage or mechanical room offer freeze protection and easier service in cold climates.
- Respect clearances. Leave room for maintenance and future replacement.
Cost and ROI: New Build vs. Retrofit
- New build: The incremental cost to upsize gas piping, plan venting, and add recirculation is modest. You reap benefits from day one.
- Retrofit: Upsizing gas lines, changing vent paths, and adding a recirc return can get expensive, which is why many homeowners hesitate. But if you design for tankless from the beginning, replacement decades down the line is simple and cost‑effective.
Tankless‑Ready Checklist
- Gas trunk sized for ~199k BTU plus other fixtures
- Utility meter capacity verified
- Vent chase framed to termination point
- Condensate drain and neutralizer roughed in
- 120V receptacle and service switch provided
- Isolation/flush valve kit specified
- Dedicated recirculation return line to mechanical room
Pulling It All Together in a New Build
When you marry these three decisions, you end up with a plumbing system that feels premium every day and quietly lowers your maintenance burden for years.
A Practical Rough‑In Map
- At the water entry:
- Main shutoff and pressure reducing valve set for ~60 psi.
- Sediment filter → carbon tank → softener/scale system (if needed) → house manifold.
- Bypass loop and sample tap installed.
- Floor drain or standpipe ready for backwash/condensate.
- At each bathroom:
- GFCI/AFCI receptacle near the toilet, mounted 12–18″ above finished floor on the tank side.
- Quarter‑turn angle stops and braided supplies.
- Toilets with solid mounting and elongated bowls if planning bidet seats.
- At the mechanical room:
- Tankless wall space with clearances.
- Gas trunk and meter sized for total connected load, including the tankless at ~199k BTU.
- Vent chase framed; termination location marked before siding or stucco.
- 120V receptacle and service switch installed.
- Recirculation return line stubbed in and labeled.
- Condensate neutralizer and drain ready.
Budget‑Smart Staging (If You Can’t Do It All Today)
- Install the infrastructure now, appliances later. Rough‑in the bidet outlets and the tankless‑ready gas/vent/electrical today, even if you start with a standard tank heater and standard seats. In the future you will thank the present you.
- Start with filtration. Point‑of‑entry filtration yields immediate benefits for every fixture and appliance. It’s also the simplest to integrate during rough‑in.
Quality and Code Considerations
- Permits and inspections matter. Water treatment devices, gas piping, and new electrical circuits require proper permits in most jurisdictions. This isn’t red tape—it’s your assurance that safety boxes have been checked.
- Choose serviceable components. Unions on every filter, isolation valves, drain pans under equipment, and labeled shutoffs make life easier when something needs attention.
- Document it. Ask your builder to leave a plumbing map with valve locations, equipment models, filter change intervals, and the recirculation control settings. Tape it in the mechanical room.
Troubleshooting and FAQs
“My city water already tastes fine. Do I still need filtration?”
Taste is subjective, but filtration is about more than flavor. It protects rubber parts from chlorine and reduces whole‑home exposure. At minimum, install a sediment prefilter and a carbon stage sized for your flow.
“Can I share one bathroom circuit for lights, fan, and a bidet seat?”
Check your local code and product specs. Many places require a dedicated 20A circuit for bathroom receptacles, and high‑end seats can draw enough current to justify their own circuit. Avoid tying into lighting; plan a proper receptacle circuit.
“What if my gas utility can’t upgrade the meter?”
Options include high‑pressure service with point‑of‑use regulators, or choosing a lower‑BTU tankless (or dual smaller units in parallel closer to loads). This is where a licensed plumber designs to the realities of your lot and utility.
“Do I need a recirculation pump if I place the tankless pump near the kitchen?”
Maybe not—but bathrooms at the far end will still wait. A dedicated recirc return line is inexpensive during rough‑in and gives you flexibility to add a pump later if needed.
“Isn’t a softener overkill?”
If your hardness is moderate to high, it’s not. Your glass, fixtures, and tankless heat exchanger will thank you. If you’re on the fence, install the loop now and add the softener later.
Maintenance Snapshot
- Filtration: Check sediment monthly at first, then set a cadence. Replace carbon media or cartridges per usage and test results. Keep spare o‑rings and silicone grease on hand.
- Bidet seats: Clean the intake screen quarterly, wipe the wand as instructed, and use the quick‑release to lift the seat for cleaning behind the hinge (a spot most people ignore).
- Tankless: Flush annually with a pump and mild descaler. Inspect vent terminations, condensate line, and isolation valves. If you have scale control, service it on schedule.
The Payoff
Build smart once, and you enjoy the benefits every single day:
- Cleaner water, kinder plumbing. Fixtures last longer, appliances run better, and your coffee tastes like it should.
- Cleaner you, fewer clogs. Bidet‑ready bathrooms boost hygiene and reduce paper waste.
- Efficient, reliable hot water. A tankless designed into the home from the start delivers performance without retrofit headaches.
When people ask me where to invest in a new home’s plumbing, these three choices rise to the top every time. They aren’t flashy finishes; they’re the quiet infrastructure that makes a house feel well designed. Start with water quality, wire your bathrooms for modern comfort, and plan your mechanicals for tankless efficiency. Nail those, and you’ll have a system that serves you well for decades.
Conclusion
The path to a durable, comfortable plumbing system isn’t complicated, but it does require foresight. Commit to these 3 Non Negotiables For Plumbing A NEW Home—whole‑home filtration, toilet‑adjacent power for bidet seats, and a tankless‑ready mechanical plan—and you lock in better water, better hygiene, and better efficiency from day one. Whether you’re building on an empty lot or taking walls down to the studs, design these features into the blueprint now. Your future self (and your plumber) will be grateful.
