A knock-down rebuild in Blacktown is assessed by Blacktown City Council under Blacktown Local Environmental Plan 2015, which controls building height, floor space ratio and flood planning by clause and map, and under Blacktown Development Control Plan 2015, whose Part C Development in the Residential Areas sets the setbacks, allotment width, garage, retaining wall and drainage controls for a dwelling house. Demolition needs consent under clause 2.7 of the LEP, so the demolition and the new dwelling are lodged as one DA with one statement of environmental effects. This guide is for home owners in Blacktown, Seven Hills, Quakers Hill, Glenwood, Doonside, Mount Druitt, Marsden Park and The Ponds who want to know which controls apply, what the numbers are and what the SEE has to demonstrate.
Key takeaways
- Clause 4.3 of Blacktown LEP 2015 sets height by the Height of Buildings Map and clause 4.4 sets floor space ratio by the Floor Space Ratio Map; the DCP’s dwelling height control simply refers back to clause 4.3.
- Blacktown DCP 2015 Part C requires a 6 metre building line to the primary road (4.5 metres in Stanhope Gardens), a 12 metre minimum allotment width for a single dwelling, and garage doors no wider than 50 per cent of the front elevation.
- Side and rear setbacks for a two storey house are 900 mm to ground floor walls, 900 mm to upper floor side walls and 3 metres to the upper floor rear wall, with eaves at 450 mm (single storey) and 675 mm (two storey).
- Section 1.7 of Part C caps cut at 900 mm and fill at 600 mm, requires 1.2 metres between terraced retaining walls and requires cut, fill and retaining walls to be shown across the whole site.
- Clause 5.21 Flood planning applies within the flood planning area, and the DCP requires stormwater to reach the street gutter or an approved discharge point, with inter-allotment drainage where the site falls away from the street.
Who this is for: home owners planning to demolish and rebuild in the Blacktown local government area who want to check their design against the LEP 2015 and DCP 2015 controls and understand what a council-ready SEE for the rebuild contains.
Do you need a DA for a knock-down rebuild in Blacktown, or can it be complying development?
Both pathways exist. The Housing Code in State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 allows a new one or two storey house, and the demolition before it, as complying development on a lot of at least 200 square metres and 6 metres wide at the building line, provided the land is not excluded (heritage, public reserves, some flood and bushfire land) and the design meets every code standard. In Blacktown flood mapping around Eastern Creek and the South Creek tributaries is the most common reason a rebuild cannot use the code. Under the DA path, clause 2.7 of the LEP requires consent for demolition, so it is included in the DA and assessed with the new house under section 4.15; our DA or CDC pathway advice tests both routes first.
What do the LEP height, FSR and flood clauses require?
Clause 4.3(2) of Blacktown LEP 2015 provides that the height of a building is not to exceed the maximum shown on the Height of Buildings Map, with the note pointing to clauses 4.3A, 4.3B and 7.7A for exceptions. Clause 4.4(2) applies the Floor Space Ratio Map and clause 4.5 defines FSR as gross floor area over site area. Section 3.2.6 of Part C states that dwelling height is to be in accordance with clause 4.3 read with the map, so the DCP adds no separate height figure for houses.
Clause 5.21 Flood planning applies to land the council considers to be within the flood planning area. Consent must not be granted unless the council is satisfied the development is compatible with the flood function and behaviour of the land, will not adversely affect flood behaviour or the safe occupation and evacuation of people, incorporates measures to manage risk to life, and will not cause avoidable erosion or riparian damage. For a rebuild on a flood-affected lot that means a flood report, floor levels set to the council’s flood planning level and often a flood-compatible ground floor. Check the section 10.7 certificate first.
What does DCP 2015 Part C require for setbacks and allotment width?
Part C section 3.2 sets the design guidelines for dwelling houses. Section 3.2.2 requires a minimum allotment width of 12 metres for a single dwelling; narrower lots are “narrow frontage allotments” assessed under section 3.7. Section 3.2.3 sets the minimum building line to the primary road at 6 metres for all locations covered by Part C, except 4.5 metres in Stanhope Gardens (6 metres where dwellings front Stanhope Parkway with rear driveway access). Any dwelling wall must be set back at least 3 metres from a rear boundary that abuts a road, and the aggregate width of garage doors or a carport must not exceed 50 per cent of the front elevation.
Section 3.2.4 covers side and rear wall setbacks for dwellings of up to two storeys: ground storey walls 900 mm from any side or rear boundary; upper storey walls 900 mm from a side boundary and 3 metres from a rear boundary; eaves and gutters 450 mm for a single storey house and 675 mm for two storeys.
| Control | Blacktown DCP 2015 Part C | Requirement |
|---|---|---|
| Allotment width | 3.2.2 | Minimum 12 m for a single dwelling; narrower lots under 3.7 |
| Front building line | 3.2.3 | 6 m to primary road (4.5 m in Stanhope Gardens) |
| Garage door width | 3.2.3 | No more than 50 per cent of the front elevation |
| Ground floor side and rear walls | 3.2.4(a) | Minimum 900 mm |
| Upper floor walls (two storey) | 3.2.4(c) | 900 mm side, 3 m rear |
| Eaves and gutters | 3.2.4(e) and (f) | 450 mm single storey, 675 mm two storey |
| Cut and fill | 1.7 | Cut max 900 mm, fill max 600 mm, 1.2 m between retaining walls |
How much cut and fill does Blacktown allow on a rebuild?
Section 1.7 Retaining walls and ground reshaping is short and strict. So that council can ascertain the extent of cut and fill, DA plans must show the location of any retaining walls, and the standards are a maximum depth of cut of 900 mm, a maximum height of fill of 600 mm and a minimum of 1.2 metres horizontal separation between terraced retaining walls. Reshaped ground not supported by a structurally adequate retaining wall must be battered at no steeper than 30 per cent (1 in 3.3) and stabilised with turf or landscaping. Cut, fill and retaining walls must be shown for the whole site, not just the building platform, and reshaping must not undermine or fill around any tree. The SEE must table the maximum cut and fill from the sections and justify any variation against the objective of stability, amenity and drainage of adjoining land.
Stormwater and drainage: where does the water go?
The DCP’s drainage requirements state that adequate provision must be made for the collection and disposal of surface and roof water, and that all stormwater shall be reticulated to the street gutter or piped to a suitable location approved by council. Where a site falls away from the fronting street, the DA must include documentation establishing a suitable drainage solution, including inter-allotment drainage through the downhill neighbour, and council will not support placing fill to channel stormwater back to the street. Part J of the DCP adds the on-site detention and water quality expectations. Lodge a stormwater concept plan from a civil engineer with the DA, and start any easement negotiation with the downhill neighbour before lodgement.
What the SEE must demonstrate, in order
- Site description from the survey: lot dimensions and width, levels, the house to be demolished, trees, easements and the section 10.7 certificate’s flood, bushfire and contamination notations.
- Permissibility: dwelling houses and demolition are permissible with consent in the R2 zone under the Land Use Table of Blacktown LEP 2015, and demolition requires consent under clause 2.7.
- LEP compliance table: height against the clause 4.3 map, FSR against the clause 4.4 map with the GFA calculation, clause 5.21 where mapped, and any clause 4.6 request.
- DCP Part C compliance table: allotment width, building line, side and rear setbacks, eaves, garage width, cut and fill, drainage, landscaping and private open space, with a justification for each variation.
- Impact assessment: shadow diagrams at 9 am, 12 noon and 3 pm on 21 June, privacy of upper floor windows, streetscape and tree removal.
- Documents lodged with the SEE: survey, architectural plans, BASIX certificate, stormwater concept, landscape plan, waste management plan for demolition and construction, cost estimate and, where mapped, flood or bushfire reports.
Definitions
- Knock-down rebuild
- Demolition of an existing dwelling and construction of a new dwelling on the same lot, assessed in Blacktown as a single DA covering the demolition under clause 2.7 and the new house.
- Flood planning area
- Land the council considers at risk of flooding for clause 5.21 of Blacktown LEP 2015, generally mapped to the flood planning level with a freeboard above the 1 per cent annual exceedance probability flood.
- Building line
- The minimum distance between the primary road boundary and the front wall of the dwelling, set at 6 metres by section 3.2.3 of DCP 2015 Part C.
- Inter-allotment drainage
- A piped stormwater line through a neighbouring lot within an easement, used where a site falls away from the street.
Frequently asked questions
What is the front setback for a new house in Blacktown?
Section 3.2.3 of Blacktown DCP 2015 Part C sets a minimum building line of 6 metres to the primary road for all land covered by Part C, except 4.5 metres in Stanhope Gardens. Garages facing the street must not exceed 50 per cent of the front elevation width.
How much fill can I place on a Blacktown block?
Section 1.7 of Part C limits fill to 600 mm and cut to 900 mm, with at least 1.2 metres between terraced retaining walls. Anything beyond that needs a justified variation in the SEE and usually a change to the floor structure.
Is my Blacktown lot flood affected?
Check the section 10.7 certificate and the council’s flood mapping. If the lot is within the flood planning area, clause 5.21 applies and a flood report with floor levels set to the flood planning level is required; the Housing Code CDC path is usually unavailable.
Can I rebuild as complying development in Blacktown?
Yes, where the lot is at least 200 square metres and 6 metres wide, is not excluded land and the design meets every Housing Code standard. Flood mapping and tree removal are the usual reasons a rebuild goes to a DA instead.
URBA prepares statements of environmental effects for knock-down rebuilds across the Blacktown local government area, with the LEP and DCP Part C compliance tables the council’s assessment officers expect and a cut and fill and drainage justification written to sections 1.7 and 4.3.4. See our town planner for Blacktown page and our SEE service, or request a fee proposal for your rebuild.
Sources and references
- Blacktown Local Environmental Plan 2015, clauses 2.7, 4.3, 4.4, 4.5, 4.6 and 5.21, accessed September 2026
- Blacktown City Council, Blacktown Development Control Plan 2015 (parts index, effective 1 February 2026), accessed September 2026
- Blacktown DCP 2015 Part C Development in the Residential Areas, sections 1.7, 3.2 and 4.3.4, accessed September 2026
- NSW Planning Portal, Housing Code, accessed September 2026
- State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, Part 3 Housing Code, accessed September 2026
- Environmental Planning and Assessment Act 1979, section 4.15, accessed September 2026
- NSW Planning Portal, BASIX, accessed September 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.