Mosman Council — Development Application Data
Development applications in Mosman face notably rigorous character controls, with streetscape and neighbourhood character incompatibility cited in 146 refusals—the most common ground for rejection in this harbourside council. Since 2021, Mosman Council has processed 2023 DAs, with 966 lodged in the last year alone and a median assessment time of 101 days. A substantial 27.34% of applications invoke Clause 4.6 variations to development standards, reflecting the challenges of building within Mosman's established low-density residential fabric. Projects span a wide cost spectrum, from 512 applications under $100k through to 110 exceeding $5M, though the 1362 applications categorised as "Other" alongside 528 alterations and additions reveal the dominance of smaller-scale residential work. Site suitability, public interest considerations, building bulk, and landscaping concerns also feature heavily in refusal decisions. A Plan Advice AI assessment for your Mosman property delivers an evidence-based feasibility report in seconds.
Determination outcomes
Real approval, refusal and withdrawal rates from finalised DAs in the Plan Advice enriched corpus.
Based on the 95.3% of DAs in our Mosman Council corpus with a confirmed determination. Applications still under assessment, and any whose outcome the council has not published, are excluded rather than estimated.
Why DAs get refused in Mosman Council
Grounds cited across 208 refused applications, read from the council's own notices of determination. Most recent determination indexed: July 2026. Most refusals cite several grounds at once, so these overlap.
Behind each ground above sits the verbatim paragraph the assessing officer wrote, the LEP and DCP clauses it was tested against, and the address and DA number so you can pull the notice yourself. 1,617 grounds across Mosman Council are indexed this way.
See the grounds in fullConditions you should expect
Approval is not the finish line — every consent arrives with conditions. This is what Mosman Council actually imposes, measured from the consent notices it has published.
Conditions marked costs money are the ones to budget for — contributions, bonds, specialist reports and public-domain works.
| 96% | Build in accordance with the approved plans | |
| 87% | Appoint a principal certifier | |
| 85% | Construction certificate before works start | |
| 83% | BASIX commitments | |
| 77% | Construction traffic management | |
| 77% | Security bond or damage depositCOSTS MONEY | |
| 77% | Long service levyCOSTS MONEY | |
| 76% | Dilapidation survey of neighbouring propertyCOSTS MONEY | |
| 76% | Erosion and sediment control | |
| 76% | Sydney Water approval (Section 73)COSTS MONEY | |
| 76% | Section 7.12 levyCOSTS MONEY | |
| 76% | Section 7.11 developer contributionsCOSTS MONEY |
Based on 1,055 approvals with a published notice of determination · 6 of the conditions above carry a cost. A condition on most approvals is effectively standard; it is not a guarantee of what any individual consent will say.
Development type mix
What people are building in Mosman Council. Ranked by DA volume.
Development cost distribution
Estimated development cost ranges reported on Mosman Council DAs.
Mosman Council DAs — common questions
Answered from this council's own determinations. Where a council has not published a figure, the question is left out rather than guessed.
How many development applications does Mosman Council handle?
Plan Advice holds 2,067 development applications for Mosman Council, 998 of them lodged in the last 12 months. The figures on this page are counted from that register, not estimated.
How long does a DA take in Mosman Council?
The median assessment time is 101 days for FY25-26, after a median 6 days to get the application accepted for lodgement. That is the council's own reported figure from the NSW Planning Portal league tables, so it covers every DA they determined — not a sample.
What share of DAs does Mosman Council approve?
80.8% of the 1,649 determined applications we hold were approved and 13.2% were refused. We can read a determination for 95.3% of this council's DAs; the rest are counted as unknown rather than assumed approved.
Why are DAs refused in Mosman Council?
Across 208 refused applications, the grounds cited most often are streetscape / neighbourhood character incompatibility (146 refusals), building height, scale, bulk or massing (117 refusals), site not suitable for the development (s4.15(1)(c)) (134 refusals). These are read from the council's own notices of determination, and most refusals cite several grounds at once.
What kinds of development are most common in Mosman Council?
The most frequent application types are alterations & additions (535), residential flat building (75), subdivision (24).
How often is a clause 4.6 variation used in Mosman Council?
565 applications — 27.33% of the register — sought a clause 4.6 variation to a development standard.
Most recent development applications
Sampled from the NSW Planning Portal open-data feed.
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