Do You Need Council Approval for a “Granny Flat”? Yes and No

A granny flat (also called a granny pod, mother-in-law unit, in-law apartment, or bonus unit) is a self-contained accommodation — inside, attached to, or completely separate from a primary home.

A granny flat is often known as an accessory dwelling unit (ADU), and many ADUs fall under the tiny house category. With the tiny living movement gaining traction and multi-generational housing becoming the norm, the granny flat is becoming more popular. No longer just for mothers-in-law, granny flats are now becoming the go-to accommodation for nannies and young-adult family members.

However, because a granny flat is technically an additional housing unit, it’s considered a “development” under the Planning & Development Acts — and therefore, owning a granny flat may require planning consent or Development Approval (DA). If your site is in an R5 residential zone in NSW, then yes — you must lodge a Development Approval with your council.

A DA is an official application you lodge with your local council to ask permission to proceed with your planned development.

If your site is in an R5 residential zone in NSW, you must lodge a Development Approval with your council.

These are the five main residential zones:

Your local council’s approval and prescribed conditions depend on the scale of your project. Each DA consent is generally based on merit and has a unique set of requirements. Council officers will determine if your DA proposal meets the local area’s relevant zoning and planning controls. They will also evaluate your property’s potential impact on the surrounding environment and neighbouring properties.

With the changes to the CDC code and the NSW government wanting to “reduce red tape,” many developments are now regulation-assessed instead of merit-based.

Homeowners in R1, R2, R3 or R4 residential zones on the Central Coast no longer need an evaluation by the council inspector.

Homeowners on the Central Coast no longer need council approval to build a granny flat on their block if the site is located in R1, R2, R3 or R4 residential zones. Still, your property needs to meet minimum site requirements, setback requirements and residential zoning requirements.

In general, you are permitted one granny flat per block.

Development Approval vs. Complying Development Certificate

In NSW, if you meet the set criteria, your granny flat can be approved without needing a standard DA. Instead, you can request a Complying Development Certificate (CDC) with a private Certifier from your local Council. The CDC is a 2-in-1 — a Development Application and Construction Certificate. Getting a CDC can fast-track the approval process by eliminating Council’s involvement and any potential objections from your neighbours.

A CDC is still subject to conditions of approval to protect the surrounding area during the construction period and life of the development. However, because a CDC can be conducted by either your local council or a private certifier, the process is faster than a standard DA.

The Affordable Rental Housing State Environmental Planning Policy (AHSEPP)

Your local council, or an accredited certifier, can certify your granny flat as complying with development — without needing a DA — provided that your granny flat meets specific standards in the Affordable Rental Housing State Environmental Planning Policy (AHSEPP).

The AHSEPP was introduced in 2009 to increase the supply and variety of affordable rental and social housing in NSW. The policy provides for the development of granny flats (i.e., secondary dwellings) to add value and flexibility to your primary home. For instance, if you have young family members or elderly relatives staying with you, you can make a second dwelling for them. You can also rent it out, as no rent provisions outlined in the AHSEPP apply specifically to second dwellings.

As a rule of thumb, to build a granny flat as complying development, it must be:
  • Established in conjunction with another dwelling (the principal dwelling),
  • On the same lot of land as the main dwelling (and not an individual lot in a strata plan or community title scheme)
  • May be within, attached to, or separate from the principal dwelling
  • Is on a lot that has an area of at least 450m²
  • Does not involve the erecting of a basement, or alterations or addition to an existing basement
  • Does not involve the erecting of a roof terrace on the topmost roof of a building, or alterations or addition to any such existing terrace
  • There must be a 12m width at the building line of the existing dwelling (if your granny flat does not meet this requirement, you can apply for an attached granny flat)
  • Maintain a 3.0m setback from the rear and 0.9m from side boundaries
  • Maintain a distance of 3.0m from any existing trees that are over 6m in height
  • Maximum 60m² internal area for your granny flat
Additional site requirements:
  • After the development, there is only one principal dwelling and one secondary dwelling, and
  • If it is not a battle-axe lot, has a boundary with a primary road, measured at the building line, of at least the following:
    1. 12 metres, if the lot has an area of at least 450m² but not more than 900m²,
    2. 15m, if the lot has an area of more than 900m² but not more than 1500m²,
    3. 18m, if the lot has an area of more than 1500m², and
  • If it is a battle-axe lot, it has an access laneway of at least 3m in width and measures at least 12m by 12m, excluding the access laneway
  • A lot on which a new secondary dwelling is erected must have lawful access to a public road
  • The site coverage of the principal dwelling, secondary dwelling and all ancillary development on a lot must not be more than the following:
    1. 50% of the area of the lot, if the lot has an area of at least 450m² but not more than 900m²,
    2. 40% of the area of the lot, if the lot has an area of more than 900m² but not more than 1500m²,
    3. 30% of the area of the lot, if the lot has an area of more than 1500m²

Maximum floor area

The floor area of a secondary home (excluding any ancillary development) must not be more than 60m², or if a greater floor area is permitted in respect of a secondary home on the land under another environmental planning instrument, that greater floor area.

The floor area of a principal dwelling, secondary dwelling and any carport, garage, balcony, deck, patio, pergola, terrace or veranda attached to either place and enclosed by a wall (other than the external wall of a dwelling) higher than 1.4m above the floor level on a lot must not be more than the following:

  • 330m², if the lot has an area of at least 450m² but not more than 600m²,
  • 380m², if the lot has an area of more than 600m² but not more than 900m²,
  • 430m² if the lot has an area of more than 900m²

Get in touch with us if you have questions. We’ll guide you through the requirements.

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