NSW CDC Requirements (Complying Development Certificate): The SEO-Heavy Guide for Dual Occupancies & Terraces

If you are planning a dual occupancy (duplex) or terrace housing project in NSW, one of the fastest approval pathways (where eligible) is a Complying Development Certificate (CDC). The most common cause of delays is incomplete documentation at lodgement. This post is a practical, SEO-focused breakdown of the CDC lodgement requirements for Dual Occupancies & Terraces, including minimum documents, common additional reports, and pre-commencement items.

What is a CDC in NSW?

A CDC (Complying Development Certificate) is an approval pathway for development that meets prescribed complying standards. An accredited certifier assesses your proposal against those standards and supporting documentation. If your design and site meet the criteria and your evidence set is complete, the certifier can issue a CDC.

CDC requirements NSW: minimum documents to lodge (Dual Occupancies & Terraces)

The following documents are the minimum requirements to lodge a CDC application and enable assessment to commence.

1) CDC application form (signed by all owners)

Complete the certifier’s CDC application form prior to lodgement. All property owners must sign.

2) Architectural plans (complete assessment set + CDC building envelope)

Architectural plans must be prepared by an Architect or Draftsperson and should include a site plan, floor plan, external elevations, sections, construction details, and the CDC building envelope. Plans must be sufficiently accurate for assessment.

Note: projects assessed under the Low-Rise Housing Diversity Code require a Registered Architect or Registered Building Designer to complete the plans.

3) Title search + DP + 88B instrument

Provide a title search to confirm ownership, plus the Deposited Plan (DP) and 88B instrument to identify restrictions or easements that may apply to the lot.

4) Section 10.7 planning certificate

Provide a Section 10.7 planning certificate to confirm zoning, permissibility of complying development, and any site sensitivities that may trigger additional reporting requirements.

5) Structural engineering plans (including soil classification)

Structural engineering plans must be prepared and endorsed by a Structural Engineer for all structural components (slab and/or piers) and must include the soil classification (it cannot be assumed).

6) Hydraulic / stormwater plans + design certification (AS3500 + Council DCP)

Provide stormwater plans prepared by a Civil/Hydraulic Engineer with supporting design certification confirming compliance with the relevant Council Development Control Plan and Australian Standard AS3500.

7) Local water authority endorsement

Provide evidence from the local water authority confirming compliance with its requirements and confirming the development does not impact existing underground infrastructure.

8) Building specifications

Provide a building specification that defines the minimum acceptable materials and workmanship standards for the building works.

9) Section 138 driveway crossing approval (if applicable)

A Section 138 approval from Council may be required for any proposed driveway crossing across the public roadway or nature strip.

10) BASIX certificate (Building Sustainability Index)

In NSW, a BASIX certificate is required for a new dwelling or for alterations and additions valued at $50,000 or more to an existing dwelling. A BASIX is also required for swimming pools above 40,000L capacity. The certificate determines the energy efficiency requirements to be incorporated into the design.

11) Long service levy receipt (where value threshold applies)

Provide a receipt confirming payment of the Long Service Levy for construction works. The levy is 0.25% of the total cost of works (materials and labour) and is required where total works are valued at $250,000 or greater.

Low-Rise Housing Diversity Code: additional CDC documents

Projects proposed under the Low-Rise Housing Diversity Code must be supplemented by a completed Design Verification Statement and a completed Design Guide Checklist confirming compliance with the required design principles. These must be completed by a Registered Architect or Registered Building Designer.

Additional documentation commonly requested after lodgement

Depending on site constraints and what is identified in the Section 10.7 planning certificate, additional documentation may be requested after the CDC is lodged and assessed. Common items include:

BAL certificate (Bushfire Attack Level)

Applicable where the lot is identified as bushfire prone. A BAL certificate is issued by an accredited bushfire consultant or Council and determines the level of construction required by AS3959. The certificate must state BAL29 or lower for CDC to proceed. Pools and non-habitable structures more than 6m away from the dwelling are generally exempt.

Flood certificate

Applicable where the lot is identified as flood prone. The certificate is to be issued by Council or an engineer and must confirm full compliance with complying development requirements.

Geotech report (landslip) - key CDC limitation

Applicable where the lot is identified as landslip prone. The report details any additional construction or engineering requirements to be incorporated into the project. Important limitation: dual occupancies or terraces cannot be approved via CDC if landslip is noted as a LEP control.

Geotechnical report (groundwater) - excavations over 1m

Applicable where excavation exceeds 1m in any location. The report must confirm that no groundwater is present at the excavation location for CDC to be permitted.

Arborist advice (works within 3m of a tree)

Applicable if works (including earthworks) are within 3m of a tree. Arborist advice may be required to determine whether the tree is protected or a significant species, depending on the council area.

Pre-commencement requirements (at least 2 days before work starts)

Some documents are required at least 2 days before work commences. If they are not provided with the CDC documentation, the CDC may be issued subject to them being provided.

Principal contractor details: owner-builder vs licensed builder

Owner-builder:

· An owner-builder permit is required if the total cost of works (materials and labour) exceeds $10,000. Note: an owner-builder permit cannot be issued until after the CDC is issued.

Licensed builder:

· If a licensed builder is the principal contractor, they must be licensed for all building work associated with the project.

· Where the contract exceeds $20,000, a Home Builders Compensation Fund (HBCF) Insurance Certificate must be provided.

Council contributions (if applicable)

Some councils charge local government contributions for new developments or developments over a certain value threshold. Your certifier may advise if fees are applicable during the assessment and approval process.

Security bonds (if applicable)

Some councils charge a refundable security bond at completion to cover potential damage to public assets such as kerbs, gutters, and footpaths. Your certifier may advise if fees are applicable during the assessment and approval process.

Quick CDC checklist (Dual Occupancy & Terraces NSW)

Minimum CDC lodgement documents:

· CDC application form signed by all owners

· Architectural plans including CDC building envelope

· Title search + DP + 88B instrument

· Section 10.7 planning certificate

· Structural engineering plans including soil classification

· Hydraulic/stormwater plans + design certification (AS3500 + Council DCP)

· Local water authority endorsement

· Building specifications

· Section 138 driveway crossing approval (if applicable)

· BASIX certificate (where required)

· Long service levy receipt (where required)

Common additional documentation (site constraints):

· BAL certificate (must state BAL29 or lower for CDC to proceed where applicable)

· Flood certificate (where applicable)

· Landslip geotech report (CDC not possible for dual occupancy/terrace if landslip is a LEP control)

· Groundwater geotechnical report for excavations over 1m (where applicable)

· Arborist advice if works are within 3m of a tree (where applicable)

Pre-commencement (at least 2 days before work starts):

· Principal contractor details (owner-builder permit > $10,000 OR licensed builder)

· HBCF insurance certificate for contracts over $20,000 (where a licensed builder is engaged)

· Council contributions (if applicable)

· Security bonds (if applicable)