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NSW Government Granny Flat Fact Sheet – The Ultimate Summary

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When doing your research you may have come across a document called the “NSW Granny Flat Fact Sheet”. Today I’m going to provide you with a summary of this fact sheet:


The Fact Sheet, also known as “Supporting Secondary Dwellings”, was released by the NSW Government in December 2011. It provided all of the requirements you must have met to have a granny flat built in NSW, including important information on the approval process.


Below is a breakdown of the Fact Sheet for you.


DON'T PAY A FORTUNE FOR YOUR GRANNY FLAT. Find out how to deal with council and build a granny flat for the lowest cost possible. Learn More.

So, let’s jump right into it.


The NSW Granny Flat Fact Sheet Explained


The NSW Granny Flat Fact Sheet first refers to the:



This was a revision made to the State Environmental Planning Policy (SEPP) on 31 July 2009, to;

  • Increase the amount of people building granny flats.


AHSEPP aimed to support and simplify the approval process for granny flats, as it introduced:


  • Complying Development (CDC), which set state-wide standards for an easier and quicker approval process.
  • Less restrictions on zoning regulations on granny flats, allowing them to be built in all residential areas.


This change was established as a demand was seen for the government to provide:


  • More affordable rental options throughout NSW, due to the amount of people waiting to be suitably accommodated.


A solution was to help provide more diverse housing choices, such as granny flats.


Supporting a person’s wish to build a granny flat on their property was also seen to have extra benefits, as it would:


  • Increase the overall value of their home, and its’ versatility.


So, the AHSEPP allowed you to decide who would be the occupants of the granny flat, such as:


  • Relatives, friends, or tenants.


There were no restraints regarding rent in the AHSEPP.


However, it is a condition of the policy that the Minister must make sure that the provisions of the SEPP, or the AHSEPP as it was known then, are reviewed at minimum every 5 years.


So there have been several updates to the SEPP since 2009 – the latest in 2021. So it is now called the State Environmental Planning Policy (Housing) 2021.


Feel free to read my article for more information on the SEPP Legislation.


Find out how to reduce confusion below


The Fact Sheet then goes on to answer common questions about granny flats.


A granny flat (also known as a secondary dwelling) must be:


  • Constructed in co-existence with another dwelling (the main home).
  • On the same block as the main home (that is, it cannot be a separate lot in a strata plan, or jointly administered lots under a community title scheme)
  • Located within a qualifying residential zone for your local Council area – advice on which can be seen here.


You have two options for approval for a granny flat, either:


  • Complying Development (CDC) – Bypassing Council and getting approved through a certifier, if you meet the standards of the SEPP.
  • Development Application (DA) – The traditional method of submitting an application to your local Council.


Both have approval processed their advantages and disadvantages, including:


  • You can be approved quicker through a CDC.
  • CDC is stricter than a DA, so you may be approved through a DA if you do not meet the standards of the SEPP.


For detailed information on both, and which option may be best for you, feel free to read my article about CDC developments.


You may convert part of your main home into a granny flat, such as your garage. Another option is an attached granny flat – you can add an extension such as a second-storey on your main home.


For ideas on what this involves and what may be better suited for you, check out this detailed post about granny flats compared to house extensions.


Or, a typical granny flat is a detached granny flat, which is separate from the main home.


The Fact Sheet then goes on to discuss the regulations for granny flats.


It gives a rundown of the basic standards that you must meet to qualify for Complying Development.


As mentioned, the rules provided from hereon are only an outline – for a full guide to the regulations, you can view:



Basic regulations include:


  • 1 main home, 1 granny flat – You can only have one granny flat with the main home on the same lot.
  • Subdividing – Once you build a granny flat, subdivision is not allowed. For more information, view my article.
  • Maximum floorspace – The largest floor area allowed for the granny flat is 60sqm, UNLESS Approval is sought through a DA. Then local Council can decide the maximum floorspace based on your main home and granny flat combined. Whether you require approval through a DA will depend on the zone your property is in.


For an example, see my article about Flood Zones, or about building in Flame Zones.


  • Minimum lot size – Your property must be at least 450sqm.
  • BCA – You must meet the applicable standards for granny flats under the Building Code of Australia. It is important to know that the way you build your granny flat will make a difference to the way it’s graded. It will either be a Class 1a or Class 2 depending on the layout of both dwellings.


Standards for Complying Development include:


  • N/A – The clause to which the document refers has since been repealed.
  • Land-based Requisites – Your property must be on land that is not limited by heritage or environmental sensitivities.
  • Development Requirements – Your granny flat must not make any external changes to the main home EXCEPT An additional door for entry.


For instance a granny flat that is built:


  1. Under the house
  2. By altering an existing basement, or
  3. On the roof of the main home


Will not be approved by Complying Development. These designs must be approved through a DA. For an in-depth look at what is required for a granny flat under your house, see my article on “Building Under Your House”.


Highest Point Rules – The granny flat must not exceed 8.5m high. This is from ground floor to the highest point of the ceiling.


Meaning, it does not include a basement or roof.


  • Requirements for Your Lot – The clause they refer to discusses the setbacks from the boundary road with a primary road. Unless you have a battle-axe lot, this distance, when measured at the building line, must be at least:
  1. 12m – For a lot no bigger than 450sqm and no smaller than 900sqm.
  2. 15m – For a lot no bigger than 900sqm and no smaller than 1500sqm.
  3. 18m – For a lot bigger than 1500sqm.


If your lot is a battle-axe lot, you must have an access laneway at least 3m wide and 12x12m long. All lots must have lawful access to a public road.


  • The extent to which the lot can be covered & maximum floorspace – The clauses they refer to discuss:


Clause 3 – Site Coverage.


The main home and the granny flat on a lot must not be greater than:


  1. 50% – On a lot 450sqm – 900sqm.
  2. 40% – On a lot 900sqm – 1500sqm.
  3. 30% – On a lot 1500sqm plus.
The following areas are not included when calculating site coverage:


  • An access ramp.
  • Any awning, blind or canopy that may be on the exterior wall of a building.
  • A deck, verandah, balcony, pergola, patio, terrace that is joined to the main home or granny flat and is not surrounded by a wall that is higher than 1.4m, measured from the floor level.
  • Any eave.
  • Any driveway.
  • Any farm building/s.
  • Any fence/s or screen/s.
  • Any pathway/s or paving/s.
  • A rainwater tank, as long as it is connected to either the main home or granny flat.
  • Spa/s or swimming pool/s.


Clause 4 – Maximum floorspace.


The floorspace of a granny flat must not exceed 60sqm, unless:


  • A larger floorspace is allowed in respect of the land as a result of another environmental planning instrument.


Meaning, if a legal instrument in your zone overrules SEPP, you may qualify to build a granny flat bigger than 60sqm.


Until then, the following regulations apply:


The floorspace of the granny flat, including any attachments (i.e. garages, carports, decks, patios, etc.) must not exceed:


  • 330sqm – On a lot between 450sqm – 600sqm.
  • 380sqm – On a lot between 600sqm – 900sqm.
  • 430sqm – On a lot bigger than 900sqm.


Clause 5 – Setbacks and floorspace for balconies, decks, patios, and verandahs.


The maximum floor area for balconies, decks, patios, and verandahs must not exceed 12m if:
  • Any portion of it is within 6m from a boundary line.
  • Any part of its’ finished floor level is higher than 2m from ground level.


Landscaping – The clause the document refers to states the amount of area that must be landscaped. For these rules, and ideas on landscaping, please view this article.


Security – Protecting all occupants privacy must be considered when building a granny flat.


For example, if a window in a occupied room in the granny flat is:


  1. Over 1m from floor level, or
  2. On a wall set back under 3m from a rear/side boundary, or
  3. The sill height is under 1.5m,


Then, that window must have a privacy screen.


Note – the clause the document refers to states that additional parking spaces are not required at the granny flat.


  • Private Space – When building a granny flat, a sufficient amount of Principal Private Open Space must be provided for the occupants of both dwellings. For a breakdown of these regulations and ideas on how to create privacy, please see my article.
  • Earth Works & Draining – The clauses referred to are below.
About Clause 18 – Earthworks, retaining walls and holding up a structure.
When building a granny flat, the maximum depth of excavation from ground level allowed is:
  1. If under 1m from a boundary = 1m.
  2. If 1m – 1.5m from a boundary = 2m.
  3. If more than 1.5m from a boundary = 3m.
UNLESS the land is:
  1. Deemed Class 3 or 4 on an Acid Sulfate Soils Map, or
  2. Within 40m of a natural body of water.


Then, the maximum depth of excavation allowed is 1m from ground level.

The maximum height of fill (measured from ground level) allowed is 1m.
However, the height of fill contained within the entire granny flat is unlimited.
Fill that exceeds 150mm over ground level and is outside of the granny flat is limited to 50% of the landscaped area.
Any retaining walls / structural supports for earthworks that exceed 600mm above or below ground level must be:
  1. Certified by a professional engineer as structurally safe and able to stand up to the forces of the sideways soil load.
  2. Designed so that they do not divert any water or sediment to a neighbouring lot.
  3. Sufficient with drainage lines that are joined to the properties stormwater drainage system.
  4. Separated from other retaining walls and supporting structures by a minimum of 2m.
  5. Installed in line with all the manufacturer’s conditions.
  6. Over 1m from a rear or side boundary (by top or bottom) if an embankment.
NOTE: Clauses 19 and 20 have since been repealed.
Clause 21 – Drainage.
All stormwater must be transferred by a gravity fed or charged system to either one of the below systems:
  1. A public drainage, an
  2. Inter-allotment drainage, or an
  3. On-site disposal.


If connected to a public or inter-allotment drainage system, the stormwater drainage systems must:


  1. Be approved under Section 68 of  Local Government Act 1993, if required. Or, if approval is not required,
  2. Comply with any regulations for the disposal of stormwater drainage in the applicable development control plan for the lot.


  • Development articulation – The Clause to which the document refers states that a granny flat or main home must have a:


  1. Front door in the building wall that faces the primary road.
  2. Window to a occupied room in the building wall that faces either the primary or parallel road (unless on a battle-axe lot).


Standards for Development Applications include:


  • Property size – Local Council cannot disallow development if the property is a minimum of 450sqm. They may approve construction of a granny flat on a property under 450sqm.
  • Car spaces – Local Council cannot reject a DA if additional car parking spaces are not supplied at the granny flat.
  • Council has Authority – Your local Councils’ policy on granny flats overrules the SEPP.


The Fact Sheet then goes on to answer the most common questions.


  • Approval – The approval process of CDC and DA is again discussed, for information you can view my article.

You can find a qualified certifier by visiting this site.

  • Rural areas – The conditions of the SEPP are not applicable to rural zones. You must get the regulations on granny flats from your local Council.
  • Dual occupancy – Only be 1 main home and 1 granny flat is allowed. For more information on dual occupancy, view my article.
  • Maximum height – 8.5m as per the SEPP, which allows 2-storeys. Local Council cannot advise otherwise.
  • Is this height an issue – No, setbacks are applied so affects (i.e. overshadowing or losing privacy) are lessened.
  • Local Councils’ power – Local Council planning policy can overrule the SEPP when the SEPP does not distinctly overrule the local Council.
  • LEP vs. the AHSEPP – In the case of a variance between the Councils’ local environmental plan and the SEPP, the SEPP will overrule the LEP.
  • Section 94 Charges – The SEPP does not impact Section 94 development fees.
  • Bushfire, flood zones – The SEPP does not overrule regulations for bushfire or flood zones.
  • BASIX – The SEPP does not alter granny flat BASIX stipulations.


The Fact Sheet then goes on to mention where you can gain more information:


  • NSW Government’s legislation site
  • NSW Department of Planning, Industry and Environment’s website
  • By calling (02) 9228 6111 or emailing housingpolicy@planning.nsw.gov.au


Finally, a checklist is provided for you to see whether a granny flat will be allowed on your property, through CDC or DA.