What Engineering Reports Do You Need for a CDC in NSW?

CDCs Are Fast, But Engineering Still Applies

A Complying Development Certificate is the fast-track approval path in NSW. It combines planning and construction approval into a single certificate, issued by a private certifier instead of council. For eligible projects, a CDC can be approved in days rather than the months a DA takes.

But faster approval does not mean fewer engineering requirements. The National Construction Code still applies. Your certifier still needs mechanical, hydraulic, and fire engineering documentation proving the building services comply.

• The project must comply with the relevant State Environmental Planning Policy (Codes SEPP)
• Common CDC-eligible projects: new dwellings, alterations and additions, commercial fitouts, change of use, demolition
• The site must not be heritage-listed, flood-prone (unless specified), or bushfire-prone above BAL-29
• The development must meet all pre-set development standards (setbacks, height, FSR, etc.)
• If the project doesn't meet every standard, it cannot go CDC and must go DA instead

• BASIX Certificate - Required for all residential CDCs in NSW. Covers energy, water, and thermal comfort. Mechanical ventilation and rainwater systems directly impact the BASIX score.
• Section J Energy Efficiency Report - Required for commercial CDCs (Class 5–9). Same requirements as a Construction Certificate.
• Mechanical Ventilation Design - Required when any space uses mechanical ventilation. Ductwork layouts, airflow calculations per AS 1668.2, plant selections. The certifier checks this against NCC Part F6 (ventilation) and Part J6 (energy efficiency).
• Hydraulic Design Documentation - Required for any changes to water, sewer, stormwater, or gas. Pipe sizing, riser diagrams, and fixture schedules per AS/NZS 3500.
• Fire Safety Schedule - Required for commercial CDCs. Lists all fire safety measures and confirms NCC compliance.
• Electrical Design - Switchboard schedules, emergency lighting, exit signs.

• Engage the building services engineer at the same time as the architect, not after
• Provide the engineer with final architectural drawings, confirmed building classification, and BASIX or Section J requirements upfront
• Ask the certifier for their checklist before lodging - every certifier has slightly different documentation preferences
• Submit all engineering reports together, not in stages
• Make sure engineering drawings match the architectural plans exactly (room names, areas, layouts)