High Efficiency Toilets (HET) are the only kind of toilet anyone should be buying for their Brooklyn green brownstone renovation. If you have an old toilet I think this is a worthwhile and justifyable new purchace. You can get one starting at $125.
There are a couple ways they could be HET – dual flush, low flush, pressure assist – but the end result is they use less water without giving a crappy flush, pun intended. Another label you will see is WaterSense, which is a good one to go by.
Here is the most recent HET study I have found – Sept 2008. It is almost a year old at time of posting but unless you are one of those people who absolutely MUST have the latest year toilet (yes these people do exist!) it should serve your needs just fine.
The graph shows MAP Flush performance, which is the amount of grams the toilet can flush at any one time. Your grandma who eats like a bird barely produces 150 grams. Your fat uncle who eats like a pig probably produces 500 grams.
Legally the toilet needs to handle 350 grams so they all can handle that. Some can go above 1,000, which is a very American thing. That way we can brag about the flush power of our toilet and impress the neighbors.
It is also a great pick up line: “Hi sexy, my toilet has a MAP Flush Performance of 900 grams. Would you like to come over and see?”