Posted on May 31, 2023 by Sue Puckeridge and Anna Sinclair

Challenging a CDC – the importance of the CDC’s purpose and the scope of s 4.31

The NSW Land and Environment Court (Court) has handed down a decision under s 4.31 of the Environmental Planning and Assessment Act 1979 (EPA Act). Section 4.31 was first introduced on 1 March 2018 and allows the Court to declare a complying development certificate (CDC) invalid under section 9.46(1) of the EPA Act.

The case provides useful guidance for interpreting the application of section 4.31 of the EPA Act, as well as determining matters that must be satisfied when applying for a CDC for development under the Exempt and Complying Development Codes SEPP 2008 (Codes SEPP).


The First Respondent, Mr Kennedy, had applied for and obtained a CDC to erect a shed on land zoned RU1: Primary Production (Site).  A dwelling house and a shed occupying an area of approximately 56m2 and two kidding pens were erected on the land.

The application for the CDC described the development as “construction of a detached shed”. The plans accompanying the CDC showed a shed 23.2m x 60m x 3.8m in an east-west direction (Shed). The area of the Shed was 1,392m2 and the height was between 3.7 metres and 5.4 metres.

The CDC did not expressly refer to the conditions specified in Schedule 6 of the Codes SEPP.

Work commenced on the Site. A building pad oriented in a north-south direction about 65m long and 29m wide was constructed together with steel reinforcement and formwork.

Following receipt of a complaint and a site inspection, the Council commenced proceedings challenging the validity of the CDC on 7 grounds.  Four of the grounds relied on s 4.31. A further ground, argued in the alternative, relied on the judicial review ground of unreasonableness. The sixth ground was that the failure to include the prescribed conditions invalidated the CDC. The seventh ground was that the CDC was uncertain and lacked finality.

Mr Kennedy argued that the Shed was ancillary to the existing dwelling house as it was to be used to store his private car collection, which was his hobby.

Ground 1 – Construing the CDC and absence of purpose

Council argued, and the Court accepted, that only the application and the CDC could be used to construe the CDC as a statutory instrument.

The Court affirmed that CDCs are interpreted according to their text, like a development consent, and by reference (at most) to documents otherwise incorporated into them in limited circumstances (at [45]).

Under planning law, development is for a purpose. A ‘shed‘ has no obvious purpose and can have many functions (at [70]).

The failure, on its face of the application for the CDC and the CDC itself, to specify the purpose of the Shed meant that the CDC lacked any purpose. Extrinsic evidence from Mr Kennedy as to his intended use of the Shed could not be used to assist in interpreting the CDC.

Consequently, the absence of a purpose meant that the Shed was not authorised as complying development because the Shed could only be authorised if it met the criteria under cl 3A.5 of Part 3A “Rural Housing Code” of the Codes SEPP. The CDC’s failure to specify the purpose of the Shed meant that the permissibility of the Shed could not be determined as required by the Codes SEPP. The development the subject of the CDC could not be characterised as complying development which may be carried out on the land for the purposes of s 4.26 of the EPA Act and the Codes SEPP.

Ground 2 – Unreasonableness

The Court accepted the Council’s submissions that without any specification of the nature of the proposed use of the Shed, no reasonable certifier could form the view that the Shed was for a purpose ancillary to the use of the dwelling house. Even assuming that the relevant development fell within the definition of ‘ancillary development’ for the purposes of the Codes SEPP, if it could not be established that it was ancillary to the existing dwelling house, then it was unreasonable for the Certifier to conclude that the development the subject of the application was complying development.

Grounds 3-5 – Scope of s4.31

Key to the Court’s determination of grounds 3-5  was the scope of s 4.31.  These grounds were, in summary, that the development was:

  • for the impermissible purpose of a car park;
  • for a proposed use that was not ancillary to the use of the existing dwelling; and
  • was not within the definition of ‘ancillary development’ in cl 1.5 of the Codes SEPP, because it is not an ‘outbuilding’ as defined in that clause as a type of Class 10a building under the National Construction Code (NCC).

The power under s 4.31 is ‘relatively unconstrained’ and it involves the Court determining for itself whether the development which a CDC purports to authorise is development for which a CDC was authorised to be issued, which includes consideration and determination of the matters in s 4.28(3) (at [88]).  Given the breadth of the task under s 4.31, this consideration (unlike the construction of the CDC itself) is not limited to material before the certifier.

In accepting the Council’s position on grounds 3-5, the Court found that:

  • given the size and area of the Shed and its intended use to store a large number of vehicles, it was a separate, independent use of the land, going well beyond use as a garage for cars used in daily life by the occupants of the house. The scale of the Shed far exceeded the kinds of development specified in cl 1.5(1) of the Codes SEPP and a freestanding garage was not within the list.
  • the fact that the Shed was useful to Mr Kennedy, as the occupier of a house on the same lot as the Shed, for a particular personal purpose does not mean its use is ancillary to a dwelling house in a legal planning sense.
  • the use of the Shed fitted the definition of a car park under the NCC and therefore was not a class 7 building and not an outbuilding, being a type of class 10a building under the NCC.

Grounds 6 – Failure to include prescribed conditions

Section 4.28(6)(a) of the EPA Act, and cl 3A.39 of the Codes SEPP requires a CDC to be issued subject to conditions required by an environmental planning instrument. Clause 3A.39 requires conditions specified in Sch 6 to be imposed in a CDC. These conditions were not included in the CDC.

The Court held that these conditions were important in ensuring environmental protection and amenity protection for neighbours. Further, the statutory scheme viewed as a whole imposes a mandatory obligation on a certifier to impose the conditions in Sch 6, and the failure to do so gave rise to invalidity of the CDC.

Ground 7 – CDC uncertain and lacks finality

The final ground relied upon by the Council was that the CDC was uncertain because:

  1. conflicting heights were shown for the shed in the architectural and structural plans referred to in the CDC; and
  2. the CDC purports to approve plans which are not correctly or precisely identified in the CDC.

Relying on Mid Western Community Action Group Inc v Mid Western Regional Council & Stockland Development Pty Ltd [2007] NSWLEC 411 (Mid Western) (at [21]), the Council argued this resulted in the CDC being imprecise and uncertain. Mr Kennedy argued that the discrepancies were generally minor and could be corrected and in any event were not so inconsistent as to result in a lack of finality preventing the development being carried out.

The Court disagreed. The discrepancies collectively meant that the CDC was uncertain. One discrepancy alone resulted in a variation in the height of the Shed wall by some 1.72m, which was not a minor amount measured in a few millimetres. This discrepancy alone made the CDC uncertain in a legal sense.


While this was not the first case determined by the Court that involved s 4.31 — the Court recently exercised its discretion under that section in Xu v Chen [2023] NSWLEC 46 — the case confirms that under s 4.31, the Court has a broad power to determine whether a CDC ‘is not authorised to be issued’ and should be declared invalid, and this requires the consideration and determination of the matters in s 4.28(3).

It also provides a useful reference for certifiers when assessing an application for a CDC and councils and other persons seeking to challenge CDCs. A CDC must specify the purpose of the complying development. If it does not, and the purpose is also not clear from the application, then the validity of the CDC could be challenged. A CDC can only be issued for a purpose which is permitted, and certifiers should ensure that they have sufficient information about the proposed use of the development to satisfy themselves of this matter. CDCs must also be carefully checked to ensure that they have been issued subject to any prescribed conditions, and also that there are no inconsistencies in the approved plans.

You can read the full judgment here.

If you have any questions about this blog post, please leave a comment below or contact Sue Puckeridge on 02 8235 9702 or Anna Sinclair on 02 8235 9713.