How Much Water Does an Old Toilet Use?
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Find out how many gallons per flush an old toilet really uses, how to check your own tank, and how much water…
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Buying Guides
New Construction Bathroom Guide: Choices and Specs
Every toilet specification you need to lock in before your rough plumbing is poured -- from rough-in distance and bowl shape to GPF rating, flush technology, and the MaP score that separates clog-proof performers from budget disappointments.
Why Trust Best Flushing Toilets
- Flushing power and MaP flush-test scores
- Water efficiency (GPF and EPA WaterSense)
- Aggregated owner reviews
- Clog resistance and trapway design
- Brand reliability and warranty
Research updated June 2026.
Quick Answer
For new construction, specify a 12-inch rough-in, elongated bowl, comfort height (17--19 inches), 1.28 GPF EPA WaterSense-certified toilet with a MaP score of at least 800 grams. TOTO Drake II, Kohler Cimarron, and American Standard Champion 4 are the three most builder-specified models that reliably pass all four criteria.
Building a new home or adding a bathroom addition gives you a rare advantage: the plumber has not yet run pipe. That means every specification -- rough-in distance, drain location, vent stack sizing, electrical circuit for a bidet -- is still on the table. Get these decisions right during the framing stage and you avoid expensive retrofits later. Get them wrong and you could face a toilet that rocks on an off-spec flange, a bowl that barely fits the alcove, or a model so water-stingy it requires double-flushing every use.
This guide walks through each decision in the order a builder or homeowner actually faces it: rough plumbing first, then fixture selection, then finish details. Every spec reference links to published manufacturer data, EPA WaterSense certification records, or MaP flush-test results from map-testing.com.
What rough-in dimension should you specify for a new construction toilet?
The standard rough-in for residential new construction in North America is 12 inches, measured from the finished wall to the center of the drain flange. Specifying 12 inches gives you access to the widest selection of toilets across every brand and price tier. Only bathrooms with unusually tight alcoves or specific design constraints warrant a 10-inch or 14-inch rough-in, and those sizes narrow your model choices significantly.
Always measure from the finished wall surface -- not the framing stud -- because drywall, tile backer, and tile itself add roughly 1 to 1.5 inches. Tell your plumber the finished rough-in, not the rough framing distance, so the drain flange lands correctly after flooring goes down. A flange that sits too low after flooring creates a rocking toilet; one that sits too high requires an extension collar.
A secondary dimension your plumber needs is the clearance from the center of the drain to any sidewall or vanity cabinet. The International Residential Code requires a minimum of 15 inches from center-of-toilet to any side obstruction, but 18 inches is far more comfortable for daily use and is the figure most designers and ADA guidance recommend for primary bathrooms.
Editorial Take
Plumbing inspectors see new construction errors most often at the flange height. After tile installation, a flange more than a quarter inch below the finished floor surface is technically non-compliant and may void the wax ring seal. Specify a flange extender allowance in your rough plumbing notes so the contractor knows to account for your flooring thickness before the concrete is poured or the subfloor is set.
Top New Construction Toilet Specifications at a Glance
| Model | Type | GPF | MaP Score | Height | WaterSense | Rough-In |
|---|---|---|---|---|---|---|
| TOTO Drake II (CST454CEFG) | Two-piece | 1.28 | 1,000 g | Comfort (17.25") | Yes | 12" |
| TOTO Aquia IV (CT447CFG) | Two-piece, dual-flush | 1.0 / 0.8 | 1,000 g | Comfort (17.25") | Yes | 12" |
| TOTO UltraMax II (MS604114CEFG) | One-piece | 1.28 | 1,000 g | Comfort (17.25") | Yes | 12" |
| Kohler Cimarron (K-3589) | Two-piece | 1.28 | 1,000 g | Comfort (16.5") | Yes | 12" |
| Kohler Highline (K-3999) | Two-piece | 1.28 | 800+ g | Comfort (16.5") | Yes | 12" |
| American Standard Champion 4 (2034.014) | Two-piece | 1.6 | 1,000 g | Comfort (16.5") | No (1.6 GPF) | 12" |
| American Standard Cadet 3 (2383.128) | Two-piece | 1.28 | 1,000 g | Comfort (16.5") | Yes | 12" |
| Gerber Viper (21-312) | Two-piece | 1.28 | 1,000 g | Comfort (16.75") | Yes | 12" |
| Woodbridge T-0001 | One-piece | 1.28 | 800 g | Comfort (17") | Yes | 12" |
MaP scores sourced from the Maximum Performance (MaP) testing program at map-testing.com. WaterSense certification sourced from epa.gov/watersense. All rough-in dimensions are nominal.
What GPF rating should a new construction toilet have?
For most new construction projects, 1.28 gallons per flush (GPF) is the practical target. It qualifies for EPA WaterSense certification (which requires 1.28 GPF or less), satisfies increasingly strict state water codes in California, Colorado, Texas, New York, and others, and -- when backed by a proper flush system -- delivers full waste removal without double-flushing.
Dual-flush models such as the TOTO Aquia IV go lower still, offering a 0.8 GPF liquid-waste cycle and a 1.0 GPF solid-waste cycle, which is useful in drought-prone regions or green building certifications such as LEED or NGBS. However, the push-button dual-flush mechanism adds one more failure point compared to a single lever, and some occupants find the button interface confusing.
Avoid spec-ing 1.0 GPF single-flush models as a blanket new construction standard unless your MaP research confirms the specific model achieves 500 grams or higher on the solid-waste test at that flow rate. Many 1.0 GPF toilets score 350 to 500 grams on MaP -- sufficient for most households but marginal in large-family settings.
Editorial Take
State water mandates are tightening. California Title 20 currently requires 1.28 GPF or less for new residential construction. Texas has similar rules under the Texas Water Code. Specifying 1.28 GPF at the project outset protects you from code compliance issues now and aligns you with the direction regulations are already moving. The marginal water savings from going to 0.8 GPF matter most in arid regions where local utilities offer rebates -- check your municipality before upgrading to dual-flush for the rebate eligibility alone.
What MaP score should a new construction toilet have?
Aim for a MaP score of 800 grams or higher for a primary bathroom or any bathroom in a home with a large family. A score of 1,000 grams -- the maximum tested -- means the toilet cleared the full test load without clogging or requiring a second flush. Models that earn 1,000 grams include the TOTO Drake II, TOTO UltraMax II, TOTO Aquia IV, Kohler Cimarron, American Standard Champion 4, American Standard Cadet 3 (1.28 GPF version), and the Gerber Viper.
For guest bathrooms or powder rooms with light use, a MaP score of 500 to 800 grams is generally adequate and may open up more design-forward or compact models that sacrifice peak flush performance for aesthetics.
MaP testing is conducted by an independent third-party lab following ASME A112.19.2 protocols. Results are publicly posted at map-testing.com, where you can look up any specific model by brand and model number before you finalize your specification.
Editorial Take
MaP score is arguably the single most predictive number for long-term owner satisfaction. A toilet with a 1,000-gram MaP score and a 1.28 GPF rating saves more water than a 1.6 GPF model with a 600-gram score -- because it never needs a second flush. The math is simple: one 1.28 GPF flush beats two 0.8 GPF flushes at 1.6 GPF combined. Prioritize MaP score before GPF when selecting for performance.
Which bowl shape and height should you specify for a new home?
Elongated bowls (roughly 18.5 inches front-to-back) are the preferred choice for primary and master bathrooms in new construction. They offer more seating comfort for adults and are the standard in most comfort-height toilet designs. Round bowls (roughly 16.5 inches front-to-back) save 2 inches of floor space and are appropriate for tight powder rooms or children's bathrooms where reducing reach-to-floor distance is a priority.
Comfort height -- sometimes called ADA height or chair height -- refers to a bowl rim that sits 17 to 19 inches from the floor, compared to the standard 15-inch height. Comfort height is now the builder-standard in most U.S. markets because it suits adult users, complies with ADA toilet height requirements (17 to 19 inches per ADAAG Section 604.4), and requires less effort for adults with limited mobility. If children under 5 will regularly use the bathroom, a step stool solves the reach problem more cheaply than a standard-height toilet solves the adult discomfort problem.
The combination of elongated bowl and comfort height is found in the TOTO Drake II, Kohler Cimarron, American Standard Cadet 3, Gerber Viper, and Woodbridge T-0001 -- all of which qualify as strong new construction specifications.
Editorial Take
Specifying comfort height across all bathrooms in new construction -- including guest baths -- adds negligible cost and significantly increases resale appeal. Aging-in-place buyers, who represent a growing share of the move-up market, prioritize ADA-compatible bathrooms. Builders who default to comfort height without being asked are meeting the market where it is heading, not where it was.
What flush technology is best for new construction?
Gravity-flush remains the dominant and most reliable technology for residential new construction. A properly designed gravity-flush system -- such as TOTO's G-Max or Tornado Flush, or American Standard's PowerWash rim -- has no pressure vessel to burst, no air compressor to fail, and is fully serviceable with standard replacement parts available at any hardware store. The TOTO Drake II uses a G-Max gravity system and scores 1,000 grams on MaP at 1.28 GPF, which illustrates how effective modern gravity flush engineering has become.
Pressure-assist is a viable alternative for commercial-adjacent settings -- vacation rentals, high-traffic guest bathrooms, and short-term rental properties -- where flush performance under heavy use is the top priority. Pressure-assist systems use city water pressure to compress air in a sealed vessel, delivering a forceful flush with less water pooling risk. The trade-off is noise: pressure-assist flushes are noticeably louder than gravity models, which makes them unsuitable for bathrooms adjacent to bedrooms.
Dual-cyclone and Tornado Flush systems (TOTO-proprietary) use two nozzles to create a centrifugal water flow around the bowl, reducing rim holes and the associated mineral buildup maintenance. These are gravity systems, not pressure systems, and represent the highest-performing gravity flush available in the TOTO lineup, including the TOTO Aquia IV and UltraMax II.
Should you choose a one-piece or two-piece toilet for new construction?
Two-piece toilets (separate tank and bowl) are easier to ship, easier to move through doorways and up stairs during construction, and generally less expensive. They are the overwhelming choice in new construction because the weight is split between two manageable pieces. Models like the TOTO Drake II, Kohler Cimarron, and American Standard Cadet 3 are two-piece designs that deliver top MaP performance.
One-piece toilets have a seamless profile with no crevice between tank and bowl, which simplifies cleaning and gives a more contemporary look. They weigh more (typically 80 to 120 pounds fully assembled) and cost 30 to 80 percent more than comparable two-piece models. The TOTO UltraMax II and Woodbridge T-0001 are one-piece options that meet the 1.28 GPF / 1,000-gram MaP benchmark.
Wall-hung toilets are a third option increasingly specified in luxury and modern-design new construction. The tank is concealed inside the wall in a carrier frame, keeping the floor open and making deep cleaning effortless. They require a reinforced wall cavity during framing -- this is the one toilet type where switching post-construction is genuinely expensive. Specify the carrier frame and in-wall tank at the rough framing stage if you want this option.
Editorial Take
Wall-hung toilets are worth the added framing cost in open-concept bathrooms where visual weight matters. The Kohler Veil and Swiss Madison Ivy both use the standard concealed carrier system, but the key spec to confirm with your framing contractor is the carrier weight rating -- it must handle a minimum 500-pound load per ASME A112.6.3, which is far higher than body weight alone because it includes the dynamic force of sitting down quickly.
Which accessibility specifications matter in new construction bathrooms?
ADA-compliant toilet installation requires the bowl rim to sit between 17 and 19 inches from the finished floor, 18 inches of clearance from toilet centerline to any sidewall, and 60 inches of clearance in front of the toilet. For new construction intended for visitability (a design standard where the main-floor bathroom can be used by wheelchair users), the toilet must have a clear floor space of 60 x 56 inches to the side of the bowl and a 36-inch grab bar on the side wall per ADAAG Section 604.5.
Grab bar blocking -- 2x10 or 2x12 lumber installed horizontally between studs at 33 to 36 inches from the finished floor on both sidewalls -- costs under $50 in materials at the rough framing stage and enables future grab bar installation without tearing out tile. Skipping it and retrofitting grab bars later requires a contractor, new drywall patches, and re-tiling around the bar locations.
For a full ADA compliant new build, also check the bathroom door: it must have a minimum 32-inch clear opening (36-inch door), and the floor space must accommodate a 60-inch turning circle or T-shaped turning space per IBC Section 1109.2.
Editorial Take
Grab bar blocking is the highest ROI item in any new construction bathroom. It costs roughly $50 in lumber and 30 minutes of framing labor. Installing a grab bar post-tile costs $400 to $1,200 depending on the tile type and how many studs need to be reinforced. Specify blocking on all bathroom rough framing plans -- not just the primary bathroom -- as future resale value increasingly reflects aging-in-place readiness.
Skirted Toilets vs Exposed Trapway: Which to Specify?
A skirted (concealed trapway) toilet hides the S-curve of the trapway behind a smooth porcelain skirt, creating a flat-sided profile that is significantly easier to clean. Swiss Madison, Woodbridge, Kohler (Veil line), and TOTO (Nexus) all offer skirted designs. For primary bathrooms where visual design and ease of cleaning are priorities, the skirted profile is worth the 15 to 30 percent price premium over a comparable exposed-trapway model.
Exposed trapway models -- including the TOTO Drake II and American Standard Champion 4 -- are not visually inferior, but the undulating trapway surface accumulates dust and requires a narrow brush to clean properly. In high-traffic or rental-property bathrooms, the cleaning time difference over years of use is meaningful.
One structural note: skirted toilets traditionally mount with bolts that go through the side skirt rather than the standard floor flange bolts. Some models require a specialty mounting kit. TOTO's UNIFIT system and Kohler's skirted mounting hardware are designed to work with a standard 12-inch rough-in floor flange, so specify the correct mounting kit on your fixture schedule to avoid installation surprises.
Editorial Take
Skirted toilets look cleaner because they are easier to keep clean. In a new construction primary bathroom where tile grout lines meet the toilet base, a flat skirted profile is also easier to caulk cleanly and creates less shadow-gap where mold can grow. Specify a skirted design for the master bath and wherever the design budget allows.
How do toilet specifications affect LEED, NGBS, and local rebates in new construction?
Green building certifications reward water-efficient plumbing fixtures. LEED for Homes (v4) awards points under the Water Efficiency category for toilets at or below 1.28 GPF. The National Green Building Standard (NGBS) awards points on a tiered scale, with additional credits for fixtures at 1.0 GPF or below. Both programs accept EPA WaterSense certification as third-party verification -- no separate testing is required if the toilet appears on the WaterSense product list at epa.gov/watersense.
Local utility rebates vary widely. Some municipalities offer $50 to $150 per toilet for WaterSense-certified installations. Others rebate dual-flush models specifically. Check your utility's rebate portal before finalizing fixture specifications, since rebate savings can offset the price difference between a basic 1.6 GPF model and a 1.28 GPF WaterSense-certified model entirely.
For a household of four people flushing an average of five times each per day, switching from a 1.6 GPF toilet to a 1.28 GPF model saves approximately 2,336 gallons per year per toilet. At national average water rates of roughly $5 per 1,000 gallons, that is about $11.68 per toilet annually -- modest in isolation, but multiplied across several bathrooms and 10 to 20 years of use, the savings are real. See our best flushing toilets guide for a broader look at efficiency-rated models across every category.
Editorial Take
Builders pursuing LEED or NGBS certification should specify WaterSense-certified toilets on every fixture schedule from day one. Substituting a non-WaterSense model mid-project to save $40 can cost a credit that requires $500 in compensating upgrades elsewhere in the Water Efficiency category. Lock in WaterSense across all bathrooms in the specification package and document the model numbers for your certifier.
Which brands and models are most commonly specified in new construction?
The following models represent the most frequently specified toilets in U.S. new residential construction, based on plumbing contractor purchasing data, builder spec sheets, and aggregated owner reviews. All meet the 12-inch rough-in standard, achieve comfort height, and hold EPA WaterSense certification (except where noted).
TOTO Drake II (CST454CEFG)
The TOTO Drake II is among the most widely specified residential toilets in the U.S. Its G-Max flush system delivers a published 1,000-gram MaP score at 1.28 GPF. The two-piece design keeps weight manageable for installation. TOTO's CeFiONtect glaze reduces particle adhesion to the vitreous china, decreasing cleaning frequency. The Drake II carries a one-year limited warranty on parts and finish. For more detail, see our TOTO Drake II review.
TOTO Aquia IV (CT447CFG)
The TOTO Aquia IV is the dual-flush option when water savings are the primary specification driver. Its Tornado Flush system scores 1,000 grams on MaP at the 1.0 GPF full-flush setting. The 0.8 GPF partial flush manages liquid waste efficiently. Cefiontect glaze is included. For projects chasing LEED or utility rebates, the Aquia IV's dual-flush performance is difficult to match in a two-piece format.
Kohler Cimarron (K-3589)
The Kohler Cimarron is a builder-grade workhorse with strong brand recognition and wide availability through plumbing supply houses. Its AquaPiston flush valve delivers 1,000 grams on MaP at 1.28 GPF. The Class Five flush technology uses a canister-style flush valve that opens 90 degrees -- significantly wider than a traditional 40-degree flapper -- increasing water flow rate through the 3.25-inch fully glazed trapway. See our full Kohler Cimarron review for installation notes.
American Standard Champion 4 (2034.014)
The American Standard Champion 4 uses a 4-inch wide flush valve and 2.375-inch fully glazed trapway -- among the largest trapway dimensions in its class. Its 1.6 GPF rating does not qualify for WaterSense, but its MaP score of 1,000 grams and documented resistance to clogging make it a common specification in rental properties and vacation homes where clog avoidance outweighs water savings goals. If WaterSense certification is required, the American Standard Cadet 3 at 1.28 GPF is the appropriate substitute. More in our Champion 4 review.
Gerber Viper (21-312)
The Gerber Viper is a less-promoted but consistently high-performing model. Its 3-inch flush valve and fully glazed 2.125-inch trapway combine for a 1,000-gram MaP score at 1.28 GPF. Gerber is a brand with a long history in the U.S. plumbing market and carries reliable parts availability through plumbing distributors. The Viper is an excellent specification when TOTO and Kohler lead times are extended during construction supply crunches.
Woodbridge T-0001
The Woodbridge T-0001 is a one-piece skirted design at a price point that competes with two-piece models from legacy brands. Its 1.28 GPF rating is WaterSense-eligible and owner reviews are broadly positive. MaP score for the T-0001 is published at 800 grams -- adequate for most households but worth noting against the 1,000-gram models above. The Woodbridge works well in guest bathrooms, powder rooms, or as the design-forward choice in a primary bath where aesthetics matter more than peak flush performance. Full details in our Woodbridge T-0001 review.
Planning for Smart Toilets and Bidet Seats in New Construction
If there is any possibility you will add a bidet seat or smart toilet in the future -- and given market trends, there is a high probability -- rough in a GFCI-protected 20-amp dedicated circuit in every bathroom during framing. The cost difference between running electrical to a bathroom during construction versus retrofitting it post-tile and post-drywall is the difference between $150 and $1,500 or more per bathroom.
Smart toilets such as the TOTO Neorest 750H, Kohler Karing, and the full lineup of washlet-integrated models require a 120V, 15-amp GFCI outlet within 4 feet of the toilet, positioned to the side or rear so the cord is not visible. This outlet must be on a circuit separate from the bathroom lighting circuit per NEC 210.11(C)(3), which requires a dedicated 20-amp circuit for bathroom receptacles. Plan the electrical rough-in accordingly.
If you are specifying a bidet seat retrofit on an existing toilet -- common in new construction where the toilet is selected for flush performance and the bidet is added later -- confirm the toilet seat bolts are standard 5.5-inch to 7-inch spacing and that the bidet seat manufacturer lists your toilet model as compatible. TOTO Drake II and TOTO UltraMax II are both designed to accept TOTO Washlet seats directly.
Editorial Take
Running electrical rough-in for bathrooms during new construction costs almost nothing incremental when the walls are open. Skipping it costs significantly when the homeowner wants to upgrade to a smart toilet five years later and discovers they need to cut drywall, re-tile around an outlet, and repaint. Add dedicated bathroom circuits to every bathroom spec as a matter of course -- it is one of those decisions you never regret and frequently wish you had made when retrofitting.
New Construction Bathroom Toilet Installation Checklist
Use this checklist with your plumbing contractor at rough-in, pre-tile, and finish stages.
Rough Plumbing Stage
- Confirm drain centerline is 12 inches from the finished wall surface (account for drywall plus tile)
- Confirm 18 inches minimum from drain centerline to any sidewall obstruction
- Confirm minimum 21 inches clearance in front of the drain location to any planned obstruction
- Install grab bar backing (2x10 lumber, 33 to 36 inches from finished floor) on both sidewalls
- Mark vent stack location for inspection approval
- If wall-hung toilet: carrier frame installed per manufacturer spec with minimum 500-pound load rating
- If smart toilet: GFCI 20-amp dedicated circuit outlet rough-in within 4 feet of toilet location
Pre-Tile Stage
- Verify flange height will be at finished floor level after tile installation (use a tile sample for measurement)
- Order flange extender collars if tile raises floor more than 0.25 inches above current subfloor
- Confirm toilet model, color, and rough-in match are on the fixture schedule
- Verify seat is included or ordered separately (many toilets ship without seat)
Finish Installation Stage
- Apply wax ring (or wax-free gasket) per manufacturer spec -- do not compress the wax before setting the toilet
- Torque flange bolts evenly to avoid cracking the porcelain base (finger-tight plus a quarter turn)
- Caulk toilet base perimeter on three sides -- leave the rear open for leak detection
- Test flush three times and check base, supply line, and tank bolts for leaks
- Register the toilet with the manufacturer for warranty activation
Frequently Asked Questions: New Construction Bathroom Guide
What is the standard rough-in size for new construction?
Twelve inches, measured from the finished wall to the center of the drain flange. This accommodates the widest selection of toilets from every major brand. Confirm with your plumber that this measurement accounts for the finished wall surface, not the framing stud.
Does new construction need a WaterSense-certified toilet?
In most U.S. states, yes. California, Colorado, Texas, New York, and many others have adopted plumbing codes that require 1.28 GPF or less for new residential construction. EPA WaterSense certification confirms compliance and also qualifies the toilet for utility rebates in many municipalities.
What MaP score should I require in my fixture specification?
Specify a minimum of 800 grams for any bathroom. For primary bathrooms and large-family homes, require 1,000 grams. The MaP score is the only independently verified measure of flush performance -- manufacturer marketing language is not a substitute.
Is comfort height required in new construction?
It is not universally required by code, but it is required for ADA compliance in accessible bathrooms. Most builders specify comfort height (17 to 19 inches) across all bathrooms as a market standard because it suits adult users and increases resale appeal. Only bathrooms specifically designed for young children may benefit from standard-height (15-inch) toilets.
Should I install grab bar blocking in new construction?
Yes, in every bathroom. Blocking (2x10 or 2x12 lumber between studs at 33 to 36 inches height) costs under $100 per bathroom during framing and makes future grab bar installation possible without drywall repair. Retrofitting after tile work costs $400 to $1,200 per bathroom.
Can I rough in for a wall-hung toilet in new construction?
Yes, and new construction is the ideal time to do it. Wall-hung toilet carrier frames must be set in the wall during framing. The tank is concealed in the wall cavity, keeping the floor open. Retrofiiting a wall-hung toilet in an existing bathroom requires opening the wall, which is expensive. Brands offering in-wall carriers include TOTO, Kohler, Geberit, and Swiss Madison.
Do I need a dedicated electrical circuit for the bathroom toilet area?
The NEC requires a dedicated 20-amp circuit for bathroom receptacles. If you plan to add a bidet seat or smart toilet -- now or in the future -- position a GFCI outlet within 4 feet of the toilet location during rough-in. Doing so during construction costs under $200. Retrofitting costs $600 to $1,500 or more.
What is the trapway size I should look for?
A fully glazed trapway of 2.125 inches or larger is the target for clog resistance. The American Standard Champion 4 has a 2.375-inch trapway -- one of the widest available. The TOTO Drake II has a 2.125-inch fully glazed trapway. Any model with a fully glazed trapway of 2 inches or larger and a MaP score above 800 grams should perform reliably.
What is the difference between a skirted and exposed trapway toilet?
A skirted toilet hides the trapway behind a smooth ceramic skirt for easier cleaning. An exposed-trapway toilet shows the S-curve and is typically less expensive. Both perform equally well if the trapway dimensions and MaP scores are equivalent. For primary bathrooms where aesthetics and cleaning frequency matter, skirted designs are worth the premium.
What clearances are required in front of and beside the toilet?
The International Residential Code requires a minimum 21 inches of clear floor space in front of the toilet and 15 inches from the toilet centerline to any sidewall. For ADA compliance, front clearance increases to 60 inches and side clearance to 18 inches from centerline. For comfortable daily use, most designers target 30 inches in front and 18 inches to the side.
Should I specify a one-piece or two-piece toilet for new construction?
Two-piece toilets are the practical choice for most new construction because they are lighter to handle during installation and cost less. One-piece toilets have a cleaner look and easier seam-free cleaning but cost more and are heavier. Both types can achieve equivalent MaP and GPF performance at their respective price points.
How many toilets should have WaterSense certification in a LEED project?
All toilets should carry WaterSense certification if LEED points are being pursued under the Water Efficiency credit category. The certification provides third-party documentation that the fixture meets 1.28 GPF without separate testing. Substituting even one non-certified model mid-project can affect your credit total.
Does the toilet brand matter in new construction?
Brand matters primarily for parts availability and warranty support. TOTO, Kohler, American Standard, and Gerber maintain broad U.S. distribution networks for replacement parts. Budget brands with obscure part numbers can become difficult to service after 5 to 10 years. For new construction where toilets will be in service for 20 or more years, specify brands with established U.S. parts distribution.
What is the best toilet for a rental property under construction?
The American Standard Champion 4 is frequently specified for rental and high-traffic applications because its 4-inch flush valve and extra-large trapway minimize service calls. The higher 1.6 GPF rating is the trade-off. If WaterSense compliance is required, the American Standard Cadet 3 at 1.28 GPF achieves 1,000 grams on MaP and is an appropriate substitute. See our full best toilet for rental property guide for more options.
Can I install a bidet seat on any toilet specified in new construction?
Most bidet seats fit elongated bowls with standard 5.5-to-7-inch bolt spacing. Confirm compatibility by checking the bidet seat manufacturer's compatibility list against your toilet model. TOTO Washlet seats are specifically designed to fit TOTO Drake II, UltraMax II, and Aquia IV bowls. For other combinations, check the bidet brand's website for the specific toilet model number.
What is the best toilet for a master bathroom in a new build?
The TOTO UltraMax II or a skirted one-piece from Woodbridge or Swiss Madison are strong choices for primary bathrooms where aesthetics matter alongside performance. For flush-first priority, the TOTO Drake II or Kohler Cimarron deliver 1,000-gram MaP at 1.28 GPF in a two-piece format at a lower cost than one-piece alternatives. See our best toilets for master bathrooms guide.
How do I specify toilets for multiple bathrooms with different design styles?
Maintain consistent technical specifications (12-inch rough-in, comfort height, 1.28 GPF WaterSense, 800+ gram MaP) across all bathrooms, then vary the style at the model level. A skirted one-piece in the master, a two-piece in secondary bedrooms, and a compact round-bowl in the powder room can all share the same plumbing rough-in while presenting different aesthetics.
What caulk should be used around a new construction toilet?
Use a 100 percent silicone caulk in a color matching the toilet (usually cotton white or white) around three sides of the base. Leave the rear of the base uncaulked so that a wax ring leak becomes visible as water at the base rather than seeping under the floor. Silicone is preferred over latex caulk for its mold resistance and flexibility as the toilet shifts slightly with use.
Is pressure-assist appropriate for residential new construction?
Pressure-assist is appropriate for rental properties, vacation homes, or any setting where flush force under heavy use is the top priority and noise is not a concern. It is generally not recommended for primary bedrooms adjacent bathrooms due to the flush noise. For main-floor or remote bathrooms with high traffic, the added performance of pressure-assist can be worth specifying.
What toilet height is considered ADA compliant?
Per ADAAG Section 604.4, the toilet seat height must be between 17 and 19 inches from the finished floor. This range corresponds to what manufacturers call "comfort height" or "ADA height." Standard toilets at 15 inches do not meet this requirement. All models referenced in this guide that carry a "comfort height" designation fall within the 17-to-19-inch ADA range.
Sources
- EPA WaterSense, epa.gov/watersense
- MaP flush testing, map-testing.com
- Manufacturer published specifications
- International Residential Code (IRC) Section P2705 -- Fixture Clearances
- Americans with Disabilities Act Accessibility Guidelines (ADAAG) Section 604 -- Water Closets and Toilet Compartments
- ASME A112.19.2 -- Ceramic Plumbing Fixtures
- National Electrical Code (NEC) Section 210.11(C)(3) -- Bathroom Branch Circuits
- LEED for Homes v4, Water Efficiency credit documentation
Our Verdict
For any new construction bathroom, the specification that protects you from plumbing regrets is this: 12-inch finished rough-in, elongated comfort-height bowl, 1.28 GPF EPA WaterSense certified, and a MaP score of 1,000 grams. The TOTO Drake II checks every box at a competitive price for primary and secondary bathrooms. Add grab bar blocking in the walls, rough in electrical for future bidet capability, and choose a skirted profile in rooms where cleaning ease matters. Get those decisions locked in before framing inspection and you avoid every common toilet retrofit scenario.
Related Guides
How we rank & our data sources
We do not run physical lab tests. Rankings are built from published, verifiable data and real owner feedback, never paid placement.
- MaP (Maximum Performance) flush scores
- EPA WaterSense certification & GPF ratings
- Manufacturer specifications (trapway size, flush-valve, rough-in)
- Verified owner reviews from Amazon, Home Depot & Lowe’s
Researched by Marcus Bell · Last updated August 14, 2026 · Our review method
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