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Tiny homes

Tiny houses have increased in popularity. With this has come an increasing amount of confusion about how they should be classed.

A growing trend is to put wheels under something that has been constructed to provide accommodation for people and call it a vehicle in an attempt to avoid needing to comply with the Building Code.

Our opinion is that unless it is a caravan which can be registered and warranted to be towed on a public road, then it is a building.

Since 2016 the Ministry of Business Innovation and Employment (MBIE) have made a number of determinations on the vehicle/building question. In all cases MBIE ruled that the structure was a building. It is therefore important that you fully understand the effects of this before you plan your tiny house project.

Design – Council’s requirements

Tiny houses are usually personalised designs specific to individual needs, so it’s difficult to provide answers for all situations. The information below has been kept to general requirements. We encourage you to come in and talk with us about your specific situation before making your decisions.

The Building Act and Resource Management Act (and the District Plan made under the Resource Management Act) are separate pieces of legislation. They have quite different purposes and principles, and can define the same term differently. For example, the particular situations of a tiny house on a site will determine whether it is a

  • “building” under the Building Act 2004, or
  • “dwelling” under the District Plan.

A vehicle-based tiny house (eg a large caravan) is valid but you need to carefully consider the vehicle/building debate if you don’t intend to use the vehicle on the road. If you intend to use it on a specific site as a dwelling/residential unit you will need to be aware of the legislation that then applies. It is the designer’s role to assess the facts and propose how it will comply with the relevant legislation, but it’s the owner’s responsibility to show that it will comply with all relevant legislation.

Note: residential building work needs to be carried out by a Licenced Building Practitioner (LBP).

Where to start

Determine exactly what you are intending to build and then make yourself familiar with all the legislation relevant to your project. If

  • you’re looking to take it on the road and journey around the country it will need to be registered and warranted as a vehicle (ie the same as a motor home or caravan) - the New Zealand Transport Agency (LTSA) can advise on registration and warrant of fitness criteria for vehicles
  • it’s intended as a dwelling, family flat or similar and located on a property for a period of time then it’s a building and will need to comply with the Building Act and District Plan requirements.

Putting it on wheels does not automatically make it a vehicle!

A building is defined under section 8 of the Building Act 2004.

It is important to understand the definition of a dwelling under the Selwyn District Plan. This will help to determine whether you need a resource consent. The District Plan contains rules for dwellings, including in relation to residential density, bulk and location, natural hazards, natural and cultural values, earthworks and vehicle access. If you don’t meet all District Plan requirements you will need a resource consent before you can start work. You can use the EPlan online tool to search the property address to find the relevant rules for the property. If you need further assistance you can come and see a planner at the Council headquarters.

Approvals required

If you intend to build a tiny house this falls under the definition of a building. You will need approval for the work (either a building consent or discretionary exemption) before proceeding, unless it is exempt work as set out in Schedule 1. Restrictions on exempt work to be aware of include in particular

  • no more than 1 storey (floor level of up to 1 metre above the supporting ground and a height of up to 3.5 metres above the floor level); and
  • no more than 10 square metres in floor area; and
  • no sanitary facilities or facilities for the storage of potable water; and
  • no sleeping accommodation, unless the building is used in connection with a dwelling and doesn’t contain any cooking facilities; and
  • sited no closer than its own height away from other residential buildings or to any legal boundary; and
  • smoke alarms installed in all sleeping areas.

Approvals in all cases may also need a resource consent where your activity is not allowed or a rule is broken under the District Plan.

You will still need approvals where

  • the tiny house is already built, or
  • you decide that your tiny house is not a building, and
  • it is parked on a site, and
  • you want to connect to services.

If your tiny house can be easily connected and disconnected to the services (eg water supply, sewer connection), then the services themselves will need building consent approval and comply with the building code. For example, a gully trap installed to collect foul water will need to

  • include a way of charging so that the trap does not dry out even when the tiny house isn’t there this can be achieved by putting a hose tap above the gully trap
  • have a vented drain line, which can be achieved a number of ways
  • is a quick-disconnect system (similar to requirements for caravans or motorhomes at a camp ground) will be needed if black water (ie from a toilet) is to be released.

Service connections for “mobile’ tiny houses

If your tiny house can be easily connected and disconnected to the services (eg water supply, sewer connection), then the services themselves will need approval and comply with the building code. For example, a gully trap installed to collect foul water will need to

  • include a way of charging so that the trap does not dry out even when the tiny house isn’t there this can be achieved by putting a hose tap above the gully trap
  • have a vented drain line, which can be achieved a number of ways
  • or a toilet will need a quick-disconnect system (similar to requirements for caravans or motorhomes at a camp ground)  if black water  is to be released.

Service connections for permanent tiny houses

If your tiny house is to have permanent connections to services, generally these require building consent approval. All drainage work must be carried out by a registered drainlayer.

Water supply must be potable. This may be council supply, or a stand alone system. If you connect to an existing dwelling then no further approval is needed. You will need approvals if there is no existing council connection or you are connecting into a stand alone water supply. For more information see our information on water supply.

Prebuilt solutions

Before you purchase a prebuilt unit to move onto your site, make sure that the manufacturer/supplier has the required building consent approval from the local council where it is being, or has been, constructed. Obtain a copy of the approval and the code compliance certificate – as a consumer this is your assurance that the work completed meets the minimum standards required by the New Zealand Building Code.

New builds

If you are building your tiny home from scratch you will need a building consent. Certain parts of the design and construction of a new house build will need to be done by a LBP. For more information see understanding the whats and the whys.

Costs Involved in building

Both resource and building approval costs are charged at an hourly rate. You pay for actual time and cost in processing your application and carrying out any inspections or monitoring.

The time taken to process an application depends on the quality of the documentation provided. Inspection costs are influenced by the proposed construction type to ensure our team see the critical parts of work at the right time.

Additional cost factors include

  • rates – the building may affect the rateable value of the property, increasing your overall rates
  • development contribution - depending on the intended use of your building, you may have a one-off charge to contribute to the cost of public infrastructure such as stormwater, wastewater, transport and reserves.

Development contributions apply to new and additional development, and can result from either a

  • resource consent
  • building consent
  • certificate of acceptance
  • or an authorisation for a service connection.

The cost of a development contribution depends on the location of the development. To help us calculate the development contribution share as much information as possible about your intentions, including

  • when your tiny house will be on site
  • who is building/placing it on site
  • how often it will be occupied
  • how long it is intended to be on the site.

Come and talk to us to find out more and get an estimate. Alternatively you can apply for a project information memorandum which will include a calculated development contribution when it is issued.

Building code requirements

A tiny house is treated like any other building under the New Zealand Building Code.

The building code is performance based and is reasonably straightforward. Your designer will need to document how each relevant clause of the building code is being met, just like any building consent application. For a tiny house, the acceptable solutions are often not suitable and alternative solutions may be needed – it’s the designer’s job to justify these.

Below we have outlined considerations under different code clauses of the New Zealand Building Code.

Power connections

The building code provisions for electricity (G9) and gas (G11) are based on any electrical and gas installation being safe. Electricians and gasfitters are self-certifying. Any 240v electrical or gas work will need to be certified just as it is for caravans.

Water use/connection to town water supply

Drinking (potable) water (G12) doesn’t need to be connected to the public water supply. For a building to be sanitary, water must be potable water for human consumption, food preparation, utensil washing and oral hygiene. A non-potable supply must be clearly marked and installed in a way to avoid the possibility of injury or illness. The designer is responsible for determining how this will be achieved.

Wastewater disposal

Connection to a sewerage system (G13) requires water-borne foul water to be released to a sewer system if it is available. Council can’t require a connection of a building to the public drain if the nearest part of the building is more than 60 metres from the public drain (see Local Government Act 1974 section 459 (7)(b)). Therefore, for the vast majority of urban sites a drain will be required unless there is a special approval for it not to be.

Onsite greywater disposal systems

Similar to wastewater disposal, water-borne foul water usually needs to be disposed of to a public drain. Any other option should be fully justified by the designer, including the reasons for a waiver of the building code.

Composting toilets

Composting toilets do not use a water-borne drainage system, so don’t need to be connected to a public drain. There is currently no acceptable solution to the building code for composting toilets, therefore the designer is responsible for showing compliance with G13. Although it is not referenced as a way of complying with the building code, designers may find useful Australian/New Zealand Standard AS/NZS 1546.2:2008 - On-site domestic wastewater treatment units - waterless composting toilets.

Foundations

Whether or not a fixed foundation is needed depends on a number of factors, including the site conditions. Some pre-built solutions are fitted with wheels to help place the building on site only. Your designer will need to determine suitable foundations for the unit, taking into consideration the weight of the building and ground stability, to keep the building level and help stop it from being overturned in strong winds or other environmental factors.

Insulation

The building code requirements for energy efficiency (H1) only apply where the energy is sourced from a network utility operator (ie a power company) or a depletable energy source (eg LPG, diesel, etc). If H1 does not apply then the insulation can be to a lower standard, but still must be enough to comply with E3 internal moisture.

Stairs and barriers

Key areas of non-compliance in many tiny houses is the lack of handrails to stairs and inadequate barriers to stop people (in particular children) from falling. The building code requirements for stairs and barriers are not particularly difficult if a designer considers them carefully and justifies the reasons for the solutions that they propose.

Compliance

Council relies to an extent on feedback from the community to become aware of non-complying activities – regardless of whether that is under the Building Act or the Resource Management Act.

Often a resource consent or enforcement action is initiated by a neighbour. We do not generally actively look for buildings that do not comply with legislation. However when a non-complying building is brought to our attention we are obliged to investigate and resolve issues where possible.

Any building non-compliance may mean a requirement to remove material/work done and/or a notice to fix, or may lead to an infringement notice. Your best approach is to do your research, and contact us if you need any clarification.

Selwyn District Council would like to acknowledge and thank the Canterbury Tiny House Society for their assistance in developing this information.

Relocatable and transportable buildings

Relocated buildings are often considered to be a cheaper or cost-effective alternative to taking on a new build.

This can be true if planned and managed well, however there are often misunderstandings about the consenting process, legislative requirements, associated costs, and people doing the work themselves.

If you’re considering relocating a building it is important to understand your obligations and what is required to make your project successful.

Things you need to consider include

  • legal status of the site
  • covenants of subdivision
  • district plan rules
  • restricted building work and owner builder exemption
  • compliance of any second hand materials
  • change of use – eg old church into a home
  • rewiring if built before 1970
  • insulation if renting out
  • alterations needed as part of relocation.

Specifically for new transportable building you need to be aware

  • that the building needs to be designed to withstand wind, snow and earthquake loads appropriate to the site your building will be located on
  • you will need to obtain a building consent for the ‘transportable building’ for the siting, foundation, access and drainage on the new site.
  • when you lodge your building consent application for the new site, you need to provide a copy of the code compliance certificate (CCC) issued by the building consent authority for the construction of the transportable building – this may be from a different BCA to the one issuing the building consent for building siting etc.

You’ll find our publication on relocated buildings [PDF, 2117 KB] helpful to get you started.

There is also a handy checklist [PDF, 81 KB] to help you gather all of the information that you need to provide to us when you submit your building consent application.

Shipping containers

Shipping containers have a limited life expectancy to other buildings. Whether the shipping container is a building depends on its intended use.

A container can be considered a building if

  • the purpose of the container is to store hazardous substances or gases as defined in regulations made under the Health and Safety at Work Act 2015, or
  • a container is on a property for any other purpose and is temporary or permanent, movable or immovable, including structures intended for occupation by people, animals, machinery or chattels.

A container on a property (other than a freight forwarding company) to temporarily store household goods until a house is built is an outbuilding with a specified intended life.

Some considerations that make it more likely to be a building

  • if the purpose of the container is not for transporting goods
  • if the container came from a company that repurposes containers
  • the longer the container has been or will be on site
  • dependant on what is in the container – eg if it has gardening tools hanging on the walls.

For more information and examples see our guide on shipping containers [PDF, 302 KB].