Building Duplexes & Dual Living Options in Hamilton
A duplex is two homes joined together by a shared fire rated wall.
The two homes are usually similar in size and layout – often the floor plans mirror each other. If you have more than two homes joined together this would be considered apartments or townhouses.
In Hamilton City, as a general rule you are allowed to build a duplex on any land that is 400m2 or over. However, you do still have to provide outdoor living areas and service courts for each unit.
In the past, these sizes were the same as your standard residential homes, but the rules have now changed so your outdoor living space grows as your number of bedrooms grows.
The City has also decreased the amount of service court space required. These changes mean that it is easier to fit duplexes on 400m2 of land and you are less likely to need two storeys in order to fit all your outdoor living requirements.
The requirements for outdoor living space for ancillary dwellings have always been less, so this hasn’t been effected as much.
There have also been changes to the way development contributions (sums charged by council to cover the cost of any infrastructure upgrades due to increased density) are charged.
They are now charged by the number of bedrooms rather than the type of dwelling (ancillary vs residential). This means, that if you are building two bedroom or three bedroom units, you pay less than if you are building larger units.
This also applies to ancillary dwellings, though ancillary dwellings are rarely more than two bedrooms.
The minimum requirement for a duplex is 400m2, but you need space for a driveway too, so at least 450m2 per duplex is advised.
For building two duplexes usually at least 900m2 is recommended, and over 1000m2 makes meeting council requirements a lot easier.
The best places to build duplexes are near high density zones as these areas it is more expected and so there is less upset to the surrounding community.
Examples of good locations are: arterial roads such as Ohaupo Rd or Forest Lake Rd, areas around Waikato University or near the Hospital.
You need at least 600m2 for a house with ancillary unit, which is more than a duplex, but it is cheaper to build and you don’t have the push back than can sometimes come from building duplexes.
Any area that isn’t new enough to have covenants against building ancillary dwellings is a good place for dual living options.
As you are building multiple houses at once, you have to expect higher costs than a single dwelling of the same size.
Both duplexes and attached ancillary dwellings (or anything with more than one kitchen) requires a firewall, which isn’t cheap to build.
You also have to factor in that you need twice as many bathrooms and kitchens which cost more to build than just lots of bedrooms or living space.
However, with more cost comes more value.
When building duplexes, you always subdivide so each unit has its own title and section. This adds a lot of value as you can sell them separately and your land cost is effectively half of what it would be if you were building a single dwelling on the same section.
Many people recognise the value of having a home and income so having a dual living property is also worth much more than a single dwelling.
In short, yes it is more expensive to build a duplex or dual living house, but you can get more value out of it!
My favourite duplex design is the Fiordland 306 because it has a really good layout and fits three bedrooms, single garage and internal laundry into each unit without being two storey.
My favourite dual living option is the Manuka 252 because you get everything you need on both sides and it looks just like one house from the street.
If you’re an investor looking for an opportunity in the wider Hamilton area, get in touch with Stroud Homes Hamilton about their duplex and dual occupancy designs.
They are a great investment in the Hamilton region.
But please remember, your time in council is likely to be longer as you have to go through resource consent, and your build time may be a bit longer too.