"I've lived with 1.6-gal. flushes for about eight years," according to Higgins. "Every six months, I retrofit a different style toilet off the shelf into my office bathroom, and I've yet to run into one I don't like. Kohler, Briggs, American Standard, Mansfield, Gerber. Someone's bringing a Toto by next week. In my office bath now, I've got a combination water closet and bidet--that's a Geberit and it works like a gem. I've looked at all of them. It's a matter of getting used to the product and not using the toilet as a wastepaper basket."

One reason that people still harbor ill feelings against 1.6-gal. toilets is that the early models were not up to the duty. Although manufacturers saw the new ultra-low-flush regulations coming, they were caught with their pants down when the government finally acted. Some early 1.6-gal. efforts were lamentably short of the mark. Cauldwell said he once got a letter from a major toilet manufacturer "apologizing for the fact that their 1.6-gal. toilet didn't work well but that they were required to make it."

A number of plumbers warned me that installing a 1.6-gal. gravity-flush toilet in an old house could lead to clogs and backups. Often, older waste pipe is 4-in. or greater dia. cast iron, which is a lot rougher on the inside than modern plastic pipe. When the cast-iron pipe was installed, toilets flushed anywhere from 5 gal. to more than 7 gal. of water. But now that they're down to 1.6 gal., that's often not enough water to power the waste through.

"Houses that have 4-in. to 6-in. cast-iron drains are a problem," said Daugherty. "When you put a 1.6-gal. toilet in with that diameter pipe, it just barely makes the bottom of the pipe wet. As a retrofit in a house with old plumbing, it's lousy. Now I run high-use fixtures, like the washing machine, just after the toilet. The washing machine will help move that waste down the line."

Washington, D.C., plumber Ken Goldman believes that retrofitting 1.6-gal. toilets is the biggest source of problems plumbers have with the new fixtures. "We're using plumbing fixtures designed for the 1990s and putting them in plumbing systems designed for the 1920s," Goldman said.

Power-assist toilets blast the waste away--If old pipes are your problem, you may be interested in the power-assist toilets that many toilet makers now offer. These toilets use compressed air to force the waste down the trap.

Although a few power-assist toilets require compressors, most use the pressure of the home's water supply to get the job done--with the help of a pressure tank. The Sloan Valve Company's Flushmate Flushometer (800-533-3450) is the industry leader in toilet pressure tanks. New on the market is the PF/2 Energizer System (W/C Technology Corp.; 888-732-9282).

Both work similarly: Water from the supply line is forced into the air-filled pressure tank at the house pressure of 60 psi or so, which compresses the air and exerts force on the water in the tank. When the flush button is pushed, the water jets into the bowl.

One benefit of a power-assist flush is that the water is contained inside the pressure tank, which is inside the china toilet tank. That insulation results in little or no tank sweating. Drawbacks include noise and price: Power assist generally adds $100 or so to the cost of a toilet.

Water rushing from the pressurized tank can be quite loud and startling. However, Bruce Martin, the engineer who developed both pressure-assist systems (he sold the Flushmate technology to Sloan), said his new P/F2 Energizer is much quieter than the Flushmate. "It's as quiet as a gravity toilet," he said.

Currently, only about 5% of toilets sold contain any type of pressure tank. Martin said the price of power-assist toilets will decrease, thanks in part to competition and volume sales. For now, only specially designed toilets can accept pressure-assist units. Martin is working on an adapter unit to convert ordinary gravity toilets to pressure assist.

One of the more promising developments in gravity-flush toilet design is the new vacuum-assist technology, which was developed by Fluidmaster and is currently featured in the Vacuity toilet manufactured by Briggs Industries (800-888-4458).

Although on the outside the Vacuity looks like any other toilet, it solves several different problems common to many 1.6-gal. toilets. First, it contains two plastic tanks within the toilet tank that hold only 1.6 gal. of water between them. If it's modified to flush more, it won't flush, according to Oscar Dufau, Fluidmaster's product manager. The tanks also prevents the exterior china tank from sweating in hot, humid weather.

More important, the system allows the toilet to give a complete, clean flush using only the rim holes inside the upper toilet bowl. There is no siphon-jet hole in this toilet. With all the water coming out of the rim holes, the bowl stays cleaner.

The Vacuity is different from other gravity flush toilets in another significant way. The Vacuity has two internal tanks and is configured in such a way that when you flush, a vacuum is created that powers the water into the bowl.

Although Briggs is the only U.S. toilet maker now using the Fluidmaster vacuum-assist technology, other U.S. companies are developing toilet prototypes that also use the technology. To keep the price of the unit at profitable levels, however, Fluidmaster has agreed to allow only four U.S. makers to license the technology.

Briggs lists its two-piece Vacuity toilet at near $300. However, I called around southern Connecticut and found a supply house that could order one for $217, plus $12 for the seat.

Within the wide range of 1.6-gal. toilets on the market are some fairly specific toilets and toilet accessories. These perform certain functions that you won't find on a run-of-the-mill fixture.

For instance, there is the ShowerToilet by Geberit (219-879-4466), a wall-hung fixture that contains a wand to give you a warm-water nether shower. The Geberit follows the shower with a flow of warm air, eliminating most needs for toilet paper. The Zoë Washlet by Toto (800-938-1541) is a high-tech toilet seat that contains a heating unit, a fan, an air purifier and a wand that sprays warmed water on your undercarriage. The Washlet also offers a prewarmed seat. And both the Geberit and the Toto offer fans that extract toilet air and pass it through a filter.

		These toilets are popular in Japan. The Toto Prominence toilet with the Zoë Washlet seat offers a warm-water spray, a prewarmed seat and a fan with filter to help clear the air. Photo courtesy of Toto

But that kind of luxury comes at a price. The Geberit ShowerToilet, which has the tank and flushing mechanism inside the wall, sells for $4,200 in white. Color models cost much more. And the one-piece Prominence toilet by Toto, including the Zoë Washlet with heated seat and a remote-control device for controlling the spray, sells for about $1,200. Newer Toto toilets will come with an antibacterial glazing, which the company says inhibits the growth of germs and kills common types of bacteria.

Another specialized toilet option is the Peacekeeper by Kohler (800-456-4537). There is no flush lever or button on toilets equipped with Kohler's Peacekeeper technology. Instead, it automatically flushes when the seat is closed, which makes it clear how it got its name. Here in Connecticut, Kohler's Wellworth toilet with the Peacekeeper installed retails for about $273 in white.

		A toilet for women who live with men. Kohler offers the Peacekeeper accessory on its toilets. There is no flush valve with the Peacekeeper; the only way to flush the toilet is to lower the seat. Photo courtesy of Kohler

Kohler also makes the Eco Lite, which replaces the standard single-flush lever with two levers. Depressing the smaller one gives a 1.1-gal. flush. Depressing the larger one gives a 1.6-gal. flush. The Eco Lite sells for about $186.

		It flushes more or less. The Kohler Eco Lite offers two different flushes. Depending on the type and size of the load to be flushed, one handle flushes 1.1 gal. of water, and the other flushes 1.6 gal. of water. Photo courtesy of Kohler.

The Triangle Ultra by Eljer (972-407-2600) is a 1.5-gal. toilet with a specially designed triangular tank that can help to solve your bathroom-space problems. With its 90° angled tank, the Triangle Ultra can fit into an odd corner of your bathroom. The Triangle lists for about $339 in blue. In white that price falls to $269.

		A right angle for a tight spot. Eljer's Triangle Ultra 1.5-gal. toilet is built for corner installation. With its triangular tank at a 90° angle, the Triangle Ultra fits neatly in a corner. Photo courtesy of Eljer

A few companies make wall-mounted, rear-discharge toilets. These toilets come in especially handy during a renovation when there's no practical way of installing a standard floor drain. The tank and flushing mechanism for these toilets are concealed inside the wall. However, because they are wall mounted, they require extra-beefy support inside the wall.

		No floor drain required. This wall-mounted toilet, the Kimera by American Standard, discharges to the rear so that no floor drain is needed. The rear-discharge feature is useful for remodels, where installing a floor drain would be impracticable. Photo courtesy of American Standard

In our grandfathers' day, many toilet tanks were mounted high on the wall above the bowl. Because of that height, the water came rushing down into the bowl with enough pressure to force nearly anything down the drain. These old-fashioned toilets now use 1.6 gal. of water and are still available. Barclay (847-244-1234) makes one in white that retails for about $850.

For those who feel at home on a throne, there's the English-made Nautilus II, which is sold in this country by Burgess International (313-292-7070). This is a real royal flush. A white Nautilus II sells for $3,000; in black, the price increases to $4,500. The mold for this lion-shaped commode is so complex that only 16 out of every 100 toilets survive the casting process.

		Maybe the Queen's got one of these. The Nautilus II Water Closet is made in England, and it is sold in the United States by Burgess International for about $3,000 in white. Photo courtesy of Burgess International

For extremely specific toilet requirements, Toto makes a toilet that analyzes your urine, takes your blood pressure and then sends that information to your doctor via a built-in modem. Unfortunately, you have to go to Japan to buy one.
 

Believe it or not, toilet making contains some highly guarded proprietary secrets. Although I could observe any part of the process, I could only photograph certain production areas. Secrets range from the brand of robot used to spray glazing on the unfired toilet to the way the rim holes are punched or drilled in the green-clay toilet bowl.

Each toilet starts with several molds, depending on the model. Each mold is filled with slip, or liquid clay, and and run through a dryer before being glazed and kiln fired. Afterward, the tank components are installed.

As important as the manufacturing process is, however, it's the research and engineering that go into the toilet and the final testing and quality control after manufacturing that make a good toilet.

Residential toilets must pass a series of ASME/ANSI tests, including a test in which 100 ¾-in. dia. plastic balls are flushed; a granule test in which 2,500 tiny plastic granules are flushed; a test in which ink lines are drawn inside the upper rim and flushed away; a dye test; and a drain-line transport test.

Every manufacturer tests toilets coming off the line. However, many manufacturers have created their own tests in addition to the ASME/ANSI requirements. One company that has its own set of standards is Toto, the world's largest plumbing-products manufacturer.

At the Toto toilet factory in Morrow, Georgia, an engineer tests toilets in a remarkably real way. He doesn't actually defecate in them, but it's close. Using a proprietary ingredient that closely resembles human feces, the engineer measures out up to 400g of this faux waste and then molds it into its familiar tubular shape.

After plopping the artificial waste into the toilet, the engineer wads up toilet-paper balls and drops them in on top of the bogus poop. Standing there in the factory watching him do this, I felt like asking if he wanted to be left alone. The purpose of this realism is to ensure that the toilets meet or exceed ASME flush standards.

According to Patrick Higgins, all toilets that pass the ASME standards tests should work the same. In theory, I guess that's true. But we all know that standards are only part of the story. The true test of whether a toilet--or anything--works as it should occurs in the real world.

I can't definitively tell you which toilets work and which don't. All the plumbers I talked to had wildly differing opinions about which is the best gravity-flush toilet. There are a few other things to consider before spending money on a new commode.

Thomas Pape, chairman of the Indoor Plumbing Committee for the American Waterworks Association Conservation Committee, suggests that homeowners buy rounded-bowl toilets instead of the elongated variety. "These just seems to work better than the elongated bowl," according to Pape. "That's especially true in a setting that might be abusive. You get a better vortex action out of a round bowl."

A new feature of modern toilets is the advent of one-piece toilets, which cost more than two-piece toilets because they're harder to make. Otherwise, there is no significant difference between one-piece and two-piece toilets. They all flush the same way. In fact, some plumbers argue that the higher-tank two-piece toilets actually flush better than the more expensive one-piece models because the water in the tank flows into the bowl from a greater height and therefore has greater head pressure to accomplish a thorough flush.

Another thing that separates cheaper gravity-flush toilets from the more expensive ones is color. Color adds a lot to the price of a toilet. For instance, if I'm willing to make do with a plain white Kohler Rosario one-piece toilet, I can buy it at my local home-supply store for $296, plus the cost of a seat. If I want it in simple gray, that price increases to $455. American Standard's one-piece Ellise toilet in white costs $720. Make it black, and it increases to $1,005.

Say you want to build a house on a big rock. You'll rely on solar collectors for electricity. Rain will supply your water. But you can't build a septic system. So your choices are either to buy a composting toilet or an incinerating toilet, to store waste in a tank or to hold it until you get off the rock.

If your concerns include the price of a septic tank and leaching field, the fate of the planet or a tight water supply, your best bet is probably a composting toilet, of which there are a variety on the market. These include BioLet (800-296-6026), Sun-Mar (800-461-2461), Phoenix (406-862-3854) and Clivus Multrum (508-725-5591).

A composting toilet works like the compost pile in your backyard. A carbon-rich material such as rice hulls or sawdust is added to the human waste. The materials then are mixed together in the composting unit, where they decompose together.

As to getting your composting toilet approved, the local health department usually has jurisdiction. Some jurisdictions recognize and approve composting toilets; others take them on a case-by-case basis.

Composting doesn't come cheap-- Prices for composting-toilet systems are generally pretty steep. A midsize Phoenix system, which includes two toilets and a basement-style composting unit, begins at about $4,600 installed, with vents and chutes, according to Glenn Nelson, who designs composting systems.

		A standard composting toilet. In the Phoenix system, a conventional composting toilet must be installed directly above the basement composting unit. Another type of toilet, the foam flush, can be installed at an angle away from the basement unit. Photo courtesy of Advanced Composting Systems

Small, self-contained composting toilets, such as the BioLet XL, sell for about $1,600. This toilet uses a 110v household current to power a heater (the rate of composting doubles for every 18°F increase in temperature), has a mixer motor and fan, and has a use capacity of four people. It needs venting just like the big composting units.

		An all-in-one composting toilet. This self-contained BioLet composting toilet contains an automatic mixer, a heating element to accelerate composting and a fan to draw odors up the vent. Photo courtesy of BioLet

The Incinolet (800-527-5551) is a self-contained unit that burns wast. For four-person use, a 120v, 1,800w Incinolet CF costs about $1,500.

		It looks like a garbage can, but it's an electric toilet. An Incinolet uses electricity to incinerate human waste rapidly, leaving an odor-free ash that can be dumped with the trash. Photo courtesy of Incinolet.

-Steve Culpepper is an associate editor of Fine Homebuilding.