Granny flat plumbing and drainage

Connecting to existing services

This is usually the part that decides whether a granny flat is straightforward or awkward. Where the existing water supply and drainage run, how far the new dwelling sits from them, whether the existing drainage has the fall and the capacity, and whether the connection point is under a driveway or a mature tree.

Worth working out early. It is much cheaper to move a building on a plan than to move drainage on a site.

The questions worth asking first

Where does the existing drain leave the property, and at what depth. Is there enough fall from where the new dwelling will sit to where it has to connect. Does the existing supply have the capacity for another bathroom and kitchen, or is it an old undersized line. And is anything permanent sitting over the route.

Four questions, and the answers usually shape where the building goes.

What we do

Full plumbing and drainage for the new dwelling. Water supply, hot water, sanitary fixtures, waste and foul drainage, stormwater, and connection back to the existing services or to the street.

Hot water for a minor dwelling

Generally its own cylinder rather than sharing with the main house. Sharing sounds economical and rarely is, once you account for the run, the heat loss and the fact that two households want hot water at the same time. Size it for the people actually living there.

Metering and who pays

If the minor dwelling is going to be tenanted, think about metering early. It is straightforward to allow for at install and a nuisance to add later.

The compliance side

Plumbing and drainage in a minor dwelling is consented work and needs certifying. Russ holds both registrations, as a Certifying Plumber and Certifying Drainlayer, so the plumbing and the drainage do not need two separate contractors or two separate sign-offs.

The building and design consent side is not ours. That sits with your designer and the council, and the rules change, so check the current position with them rather than relying on what a neighbour did three years ago.

Working from plans

If you have drawings, send them through. We can price off plans, and picking up a services problem at drawing stage saves everybody money.