Information about specific planning requirements if you are wanting to build an additional small residential unit on your residential zoned property.

Under the Christchurch District Plan

A minor residential unit is a small self-contained, detached building that is intended to contribute to a range of housing choices within the District.

The Christchurch District Plan recognises that small residential units can be accommodated on existing zoned properties of a certain size that already contain one existing residential unit, without affecting the character of the area. These units are eligible for some exemptions from the usual rules for residential units in the residential zones where they are permitted.

To qualify for these exemptions minor residential units must be detached from the existing residential unit and be the following size:

Zone Size of minor residential unit

Residential Suburban, Residential Suburban Density Transition, Residential New Neighbourhood, Residential Banks Peninsula, Residential Hills, Residential Large Lot, Residential Small Settlement

35-80m2 gross floor area

In the Residential Suburban, Residential Suburban Density Transition, Residential Banks Peninsula and Residential New Neighbourhood zones the existing site containing both units shall have a minimum net site area of 450m2. In the Residential Hills zone the site must have a minimum net site area of 650m2.  In the Residential Large Lot zone the site must have a minimum net site area of 1500m2 – 5000m2 depending on whether the site is located within an overlay area – refer Rule of the District Plan.  In the Residential Small settlement zone the site must have a minimum net site area of 1000m2.

The parking areas of both units must be accessed from the same access.  The minor residential unit must provide one parking space and the existing residential unit one or two, depending on the size of the unit.

On sites in the Residential Suburban, Residential Suburban Density Transition and Residential Banks Peninsula zones there must be a total outdoor living space on the existing site (containing both the units) with a minimum area of 90m2 and a minimum dimension of 5m.  This total space can be provided as:

  • a single continuous area; or
  • be divided into two separate spaces, provided that each unit is provided with an outdoor living space that is directly accessible from that unit and is a minimum of 30m2 in area.

If the site is within a Character Area overlay a minor residential unit will generally require resource consent due to the minimum net site requirements for residential units in Character Areas. In addition, consent will be required if the minor residential unit is: 

  • visible from the street;
  • located in that part of the site between the road boundary and the main residential unit on the site.

Minor residential units must meet the built form standards for residential units other than those relating to site density (for sites outside of Character Areas) and outdoor living areas or resource consent obtained for any non-compliance.    Minor residential units must also be a maximum height of 5.5m and single storey only in the majority of zones.

There are no limits to occupation of the minor residential unit i.e. it is not restricted to dependent relatives or older persons and no encumbrance is required to be registered on the title.

Subdividing minor residential units 

There is no specific provision in the District Plan for subdividing minor residential units from the primary residential unit.  This means that resource consent would be required to do this, usually as a non-complying activity due to the inability to meet the minimum net site area requirements for standalone residential units. 

Family flats

There is still the ability to construct a family flat in conjunction with a residential unit in all residential zones.  Family flats are different from minor residential units in that they must only be occupied by family member/s who are dependent in some way on the household living within that residential unit.  This requirement is secured by an appropriate legal instrument on the title of the site which ensures that the use is restricted in this way. 

Family flats can be attached or detached and are considered to be part of the residential unit on the site.  They must comply with all the built form and other standards for residential units in the zone in which they are located.  If the family flat is no longer required by the dependent relative, it must be removed from the site, have its kitchen removed or otherwise demonstrate compliance with the requirements for a minor residential unit if it is located in a zone where minor residential units are permitted.

Development contributions

A minor residential unit is considered to be a development under the Council's Development Contribution Policy 2015 and is therefore subject to a development contributions (DC) assessment. A minor residential unit is however entitled to have the benefit of the small residential unit adjustment which can reduce the DC requirement by up to 40%. A further 10% reduction can be applied to developments that meet Council's Small Residential Unit Rebate Criteria.

Any applications to develop a new family flat or convert a family flat that did not exist prior to 6 December 2013 into a residential unit will be assessed for development contributions. However, these developments will also be eligible for a small residential unit adjustment.

For more information please visit Development Contributions(external link) or contact a Development Contributions Assessor at

Contact us

For general enquiries regarding resource consents please contact the Customer Centre on (03) 941 8999 or email