Since 21 March 2026, section 4.55 of the Environmental Planning and Assessment Act 1979 still gives NSW home owners three ways to change an approved DA without a new one, but the line between them has moved. Section 4.55(1) now covers modifications with no environmental impact as well as minor errors, is not notified, and must be decided within 14 calendar days or council loses the power to refuse it. Section 4.55(1A) remains for minimal impact changes and section 4.55(2) for larger changes that still leave the development substantially the same. You also now have six months, not 28 days, to seek a review of a modification decision.
Key takeaways
- The new rules apply to modifications lodged from 21 March 2026, whenever the DA was approved.
- Section 4.55(1) now includes modifications with no environmental impact, and one not determined within 14 calendar days of lodgement cannot be refused.
- Within those 14 days council can still refuse a 4.55(1) if it sees an environmental impact, and you then lodge under 4.55(1A) or 4.55(2).
- A review of a council’s modification determination can now be requested within six months instead of 28 days.
- Since 1 July 2026 a NSW Government referral of a modification costs $550 per unique referral on a 4.55(2) and nothing on a 4.55(1) or 4.55(1A).
Who this is for: home owners who need to change an approved house, knock-down rebuild, duplex or granny flat consent in NSW and want to choose the right pathway and know their options if council says no.
Updated guide. This guide replaces our earlier article Section 4.55 modifications: changing an approved DA without a new DA, which reflects the law before the Planning System Reforms Act 2025 commenced.
What are the three section 4.55 pathways now?
The modification changes, including new section 4.55A of the Act and section 118A of the Environmental Planning and Assessment Regulation 2021, started on 21 March 2026. Modifications with no environmental impact moved from section 4.55(1A) to section 4.55(1).
| Pathway | What it covers | Notification | Decision time | If you disagree |
|---|---|---|---|---|
| Section 4.55(1) | Minor error, misdescription or miscalculation, and modifications with no environmental impact | Not notified | 14 calendar days from lodgement; after that it cannot be refused | A non-reviewable pathway; if refused, lodge under 4.55(1A) or 4.55(2) |
| Section 4.55(1A) | Minimal environmental impact, substantially the same development | Depends on council’s notification rules | Ordinary assessment, with deemed refusal rights | Division 8.2 review within six months, or an appeal |
| Section 4.55(2) | Other changes that leave the development substantially the same | Usually notified under council’s rules | Ordinary assessment, with deemed refusal rights | Division 8.2 review within six months, or an appeal |
Consents granted by the Land and Environment Court are still modified under section 4.56, which has no “no environmental impact” category. Some reform provisions on modifications have not commenced, including changes to section 4.55(2)(b) on concurrences and referrals, so the existing wording still applies there.
Which house and duplex changes moved from 4.55(1A) to 4.55(1)?
Neither the Act nor the Department’s FAQ lists which changes have no environmental impact; council decides case by case. The table below is how our planners read the new pathway for typical residential consents: a guide, not a rule.
| Typical change | Usual pathway | Why council may see it differently |
|---|---|---|
| Wrong lot number, plan reference or miscalculated figure in a condition | 4.55(1), minor error | The Department confirms errors in a Notice of Determination are fixed this way |
| Internal layout change with no change to floor area, height, footprint, windows or use | Arguably 4.55(1) | A change to BASIX commitments or floor area can create an impact |
| Equivalent external material in a similar colour | Possibly 4.55(1) | Heritage, streetscape or a materials condition points to 4.55(1A) |
| Moving or enlarging a window facing a neighbour | 4.55(1A) | Overlooking and privacy are environmental impacts |
| Small footprint shift within setbacks, a new or deleted pergola or deck | 4.55(1A) | Larger shifts near a boundary can move it to 4.55(2) |
| Extra floor area, a higher roof, a new driveway or parking layout | 4.55(2) | Bulk, overshadowing and traffic need fuller assessment |
| Adding a storey, a dwelling or a lot | New DA | Usually fails the substantially the same test |
If unsure, 4.55(1A) is often safer: a refused 4.55(1) costs the fee and two weeks.
How does the 14-day deemed approval work?
The Department’s FAQ calls it a 14-day deemed approval mechanism:
- Lodgement starts the clock. Lodgement is the day after council receives payment.
- Early screening. Councils are encouraged to check the pathway within 7 days and suggest another if needed.
- Information requests do not pause it. The clock keeps running, and if critical information is not provided, council can refuse.
- Calendar days count. Weekends are included; if day 14 is a weekend, public holiday or bank holiday, the period runs to the next business day.
- Council can refuse within the period if it forms the view the change has an environmental impact. You then lodge under 4.55(1A) or 4.55(2) with the information needed to assess it.
- After day 14, approval only. Under section 4.55A a late 4.55(1) cannot be refused. Council can still impose conditions that are not inconsistent with the modification and do not defeat its purpose.
The 4.55(1) fee was not increased. Do not build to the changed plans until the modified consent is issued and your certifier has updated the construction certificate where needed.
Does the substantially the same test still apply?
Yes. The test is written into sections 4.55(1A) and 4.55(2), and the Department’s reform material does not change it. The Land and Environment Court has read it as essentially or materially the same, comparing the modified and approved development in qualitative and quantitative terms. On residential consents:
- Moving a garage, enlarging a bedroom or altering a roof form usually passes.
- Adding a storey to a single storey house, or converting a house into a dual occupancy, usually fails.
- Changing the number of dwellings or lots fails almost every time.
- A run of small modifications can fail together, because the comparison is with the original consent.
What does council weigh on a 4.55(1A) or 4.55(2)?
The reforms clarify that the section 4.15(1) matters are considered only to the extent they are relevant to the modification. For applications lodged from 15 December 2025, section 4.15(1)(b) refers to the significant likely impacts of the development, while section 4.17(1)(a1) still allows conditions about a likely impact. Council also considers the reasons the consent was granted, so a rear setback condition imposed to protect a neighbour’s sunlight is read for that purpose. A breach of an LEP development standard still needs a clause 4.6 variation request.
A strong application includes clouded amended plans, a short statement explaining the pathway and the substantially the same assessment, a comparison table (approved, proposed, control, compliance), and an updated BASIX certificate if commitments change. For a 4.55(1), explain clearly why there is no environmental impact.
When does a modification need a DCA referral?
From 1 July 2026, integrated development, concurrence and consultation are collectively called referrals, set out in Chapter 4 of State Environmental Planning Policy (Planning Systems) 2021. The Development Coordination Authority (DCA) gives a single response to NSW Government referrals through the NSW Planning Portal within 28 calendar days, starting once council refers and any fee is paid. A modification needs referral only if it:
- triggers a referral requirement that did not apply to the original DA, or
- would change a condition imposed because of a previous referral.
On a house, that might be a change on bush fire prone land that no longer complies with Planning for Bush Fire Protection. For modifications lodged on or after 1 July 2026 the fee is $550 per unique referral on a 4.55(2), with no fee on a 4.55(1) or 4.55(1A). The Department says the DCA will respond in time for councils to meet the 14 days on a 4.55(1). Council decides which referrals apply, so ask early.
What if council refuses your modification or does not decide it?
Under Division 8.2 of the Act, amended section 244 of the Regulation now gives six months, not 28 days, to request a review of a modification determination, with no time limit on council deciding it. If council staff made the decision and a local planning panel exists, you can ask the panel to do the review; you cannot choose the elected council or a particular officer. If the panel made the original decision, the panel reviews it.
- You cannot appeal to the Land and Environment Court while a review is underway, but the six-month appeal clock pauses until it ends.
- The right to appeal a deemed refusal now lasts until the application is determined. Assessment periods are unchanged at 40 to 90 days after lodgement depending on development type, excluding stop-the-clock periods; confirm yours with council.
- The reforms did not change appeal rights for a 4.55(1).
The new review rules also cover earlier determinations not under review or appeal at 21 March 2026.
Does a modification extend the life of your consent?
No. Under section 4.53 a consent generally lapses five years after it operates unless works have physically commenced. A modification does not extend that period, and a lapsed consent cannot be modified or revived. The extended COVID lapsing provisions were removed from 15 December 2025, although consents that already had extended lapse dates keep them. A consent can still be modified after work starts, but it is cheaper and safer before the construction certificate issues.
Definitions
- Substantially the same development
- The threshold test for 4.55(1A) and 4.55(2): the modified development must be essentially or materially the same as the approved one.
- No environmental impact modification
- A change council accepts has no environmental impact, lodged under section 4.55(1) since 21 March 2026.
- Deemed approval
- Under section 4.55A, a 4.55(1) not determined within 14 calendar days cannot be refused and can only be approved.
- Division 8.2 review
- A review of a determination by council or its local planning panel, requested within six months.
Frequently asked questions
Can council refuse a section 4.55(1) modification?
Yes, but only within 14 calendar days, for example if it sees an environmental impact or critical information is missing. After that it can only approve, with conditions that do not defeat the modification.
How long do you have to ask council to review a refused modification?
Six months from the determination, replacing the old 28 days. If council staff decided it and your council has a local planning panel, you can ask the panel to do the review.
Will my neighbours be notified of a section 4.55(1) modification?
No. Section 4.55(1) applications are not notified. Notification of a 4.55(1A) or 4.55(2) depends on council’s rules.
Does a section 4.55 modification extend a development consent?
No. The lapse date runs from the original consent, and a modification cannot extend or revive it.
Which rules apply to a modification lodged before 21 March 2026?
The pathway changes do not apply to it, so the old 4.55(1A) rules govern it. The new review period and deemed refusal appeal rights may still apply, so confirm your position with council.
Our planners prepare section 4.55 modification applications and can tell you whether a change is a realistic 4.55(1). If you need to change an approved house, duplex or granny flat consent anywhere in NSW, you can request a fee proposal.
Sources and references
- Environmental Planning and Assessment Act 1979, sections 4.15, 4.53, 4.55, 4.55A, 4.56 and Divisions 8.2 and 8.3, accessed November 2026
- Environmental Planning and Assessment Regulation 2021, sections 118A and 244, accessed November 2026
- Information sheet: Second commencement of the Planning System Reforms Act 2025, accessed November 2026
- Planning System Reforms, Second Proclamation FAQ (March 2026), accessed November 2026
- Information sheet: First commencement of the Planning System Reforms Act 2025, accessed November 2026
- Fact sheet: What’s changed for councils from 1 July 2026 (August 2026), accessed November 2026
Information disclaimer. This article is general planning information prepared by the URBA Planning Team and is current at the date of publication. It is not planning, legal or financial advice for any specific property. Planning instruments, development control plans, state policies and the National Construction Code are amended regularly and councils interpret them differently; the controls quoted here should be confirmed against the versions in force at the date of lodgement and against the consent authority’s current requirements. Reliance on this article is at the reader’s own risk. URBA Planning, a division of Contrive Consultants Pty Ltd, accepts no liability for loss arising from its use. For advice on a specific site, contact URBA for a fee proposal.