New high efficiency toilet requirements

New High-Efficiency Toilet Requirements in the BC Building Code

This has been released by the province of BC. It shows that it will be mandatory for all people to install HETs and HEUs effective Oct 3 2011.


The Province is taking another step toward increased water efficiency through new high-efficiency toilet (HET) and high-efficiency urinal (HEU) requirements in the BC Building Code. Effective October 3, 2011, HETs or dual-flush toilets will be required in new residential buildings or when renovations involving plumbing fixtures occur. Whenever urinals are installed, HEUs will be required.

Toilets and urinals represent 30 to 40 per cent of domestic water use in households and in commercial and institutional buildings. Installation of more efficient models results in significant water savings. While the BC Building Code currently requires toilets with a 6-litre flush volume, high-efficiency toilets, which have a flush volume of 4.8 litres or less, are now available.

High-Efficiency Toilets

High-efficiency toilets (HETs) have a maximum flush volume of 4.8 litres. Dual-flush toilets are classified as HETs because the ratio of reduced flushes (up to 4.1 litres) to full flushes (up to 6 litres) results in an effective flush volume that is less than 4.8 litres. On average, high-efficiency toilets use at least 20 per cent less water than the 6-litre models that are currently required in B.C.

Effective October 3, 2011, HETs or dual-flush toilets will be required in new residential buildings or when renovations involving plumbing fixtures occur. The requirement for toilets with a maximum flush cycle of 6 litres in industrial, commercial and institutional buildings will remain unchanged.

While some early low-consumption toilets did not perform well, in recent testing by Veritec Consulting and Koeller and Company, all of the high-efficiency models (over 100) demonstrated good to excellent flushing performance.

According to several recent research reports, HETs have no difficulty meeting the waste transport requirements typical of residential drainline installations. However, when HETs are installed in industrial, commercial and institutional buildings, there are concerns about the drainline carry of a 4.8 litre flush volume. Until further research on drainline transport issues becomes available, the BC Building Code’s HET requirement will be limited to residential buildings.

Availability of HETs is still somewhat limited, but costs are comparable to quality 6-litre models. The requirement for HETs will not become effective until October 3, 2011, giving suppliers time to reduce existing inventory and bring in new HET stock.

High-Efficiency Urinals

A high-efficiency urinal (HEU) is a fixture with a flush volume of 1.9 litres or less. HEUs use approximately one-third of the amount of water used to flush the average urinal. Based on average usage, a single HEU can save close to 18,000 litres of water per year.

Whenever urinals are installed, HEUs will be required.

While a performance testing protocol similar to that for toilets has not yet been developed for HEUs, flushing HEUs must meet the same performance standards as other flushing urinals sold in North America. Because the flush volume of a urinal can often be set at either 3.8 litres or 1.9 litres through the flushometer valve, the cost and availability of HEUs is the same as that of higher-volume urinals.


The new requirements will come into effect on October 3, 2011, to address implementation issues and to better coordinate with the next edition of the Building Code.

The new requirements will apply to building permit applications that are submitted on or after October 3, 2011.