Low-flow toilets

The scoop on how they work and how to choose one

Flush with ingenuity

Our toilets are thirsty beasts, chugging about 30 per cent of the water we use daily. The good news is there’s no longer a dearth of water-saving cottage loos.

Just add a little water

More manufacturers than ever are rolling out thrones with low- or dual-flush mechanisms. To count as low-flow, each flush can use no more than six litres of H2O. Compare that with older models that unleash 18 litres. Dual-flush systems have two flush options, one an even lower-volume flush for liquid waste and paper, using only three litres. Some loos liquefy waste and paper in a macerator equipped with a rotating cutting blade before pumping it through narrower-than-standard piping, requiring only four litres per flush.

Go dry or go home

The greenest option may be to forego water altogether, and this is sometimes the only choice for remote cottages or hideaways on rocky islands. The most rustic such system is the outhouse, where waste is broken down by naturally occurring bacteria, but be sure to avoid runoff into lakes and streams by building it according to the Ontario Building Code. If you prefer the great indoors, the latest composting toilets look like your home loo, but instead of ridding waste via a drain, they convert it to soil. A ventilation fan, and sometimes a heating unit, helps evaporate water, which makes up about 90 per cent of sewage. The rest—solids sanitized by oxygen-loving microbes—can be used in your garden (but not on veggies). Incinerating toilets burn the waste, so all you end up with is ashes.