Description

Today, selecting low flow toilets are not an option, but required by federal regulations. The National Energy Policy Act of 1992 mandated that by 1994, all newly manufactured residential toilets use 1.6 gallons per flush (gpf) compared with the standard 3.5 gpf. However, additional water efficiency options are still available as well as toilets that require less maintenance due to improved engineering which will ensure continued affordability. There are three primary flushing types available in today’s toilets: pressure-assisted, vacuum-assisted, and gravity-assisted.

Urban Edge Guidelines

• Select a toilet with a trapway that is 2” or greater. Toilets with larger diameter pipes tend to have less blockage. Standard residential toilets have a trapway of 1 ½” but toilets are available with trapways up to 4” in diameter.
• Only use in-bowl toilet cleaners. Avoid using in-tank chlorine cleaners since this damages the toilet flapper and may cause leaks. 
•  If known, try to select toilets that can handle over 250 grams of waste per flush as described by the Maximum Performance Testing of Popular Toilet Models. Toilets are available that flush up to 800 grams of solids. 
•  Select models that can be easily set up to flush the appropriate volume as well as models designed with a standard flapper so that it can be replaced with an equivalent model from a renovation center.

Spotlight on Urban Edge

Retrofitting

Since 1992 toilets have been required by code to use 1.6 gallons per flush maximum and many met this requirement prior to federal law. We conducted reviews of toilets from five Urban Edge developments and none use more than 1.6 gallons per flush (gpf). Water usage for all modern toilets typically used in multi-family residential construction will be relatively equal except for the dual flush toilets which use 0.8 – 1.1 gallons per flush when there are minimal solids to flush. Thus, upgrading existing 1.6 gpf toilets to new 1.6 gpf toilets provides no lifecycle cost savings from reduced water usage unless the existing toilets leak. The main advantage of replacing toilets would be to use newer models with more durable moving parts or ones that clog less often, reducing maintenance calls.

Options and Criteria Review

Toilet Types

There are three primary types of toilets:

• Gravity-Assisted (Typical residential toilet)
• Pressure-Assisted
• Vacuum Assisted

Click here to learn morea bout each type. Click here to read about some modified versions.

Costs

Click here to learn more.  Also, click here to see our life cycle cost analysis comparing a standard gravity-assisted toilet to a pressure-assisted dual-flush toilet.

Resources

For purchasers

• Urban Edge Quick Recommendations
• Toilet Testing Standards

For Maintenance Staff, Users

• Flapper Replacement Tips

References