How the NBN new developments process works
From design to the Certificate of Practical Completion: who does each step, what NBN checks, and where projects most often lose time.
Reviewed 14 October 2026 against NBN's pit and pipe guidance
In short: the developer designs the pit and pipe network, NBN reviews and accepts the design, the developer builds it, NBN checks the as-builts and inspects the work, and NBN then issues a Certificate of Practical Completion and installs its network. Pit and pipe design is the first step, and a design that is right first time keeps every later step moving.
Who is responsible for what
NBN's pit and pipe model splits the work clearly. The developer designs and builds the pits and conduits inside the development. NBN reviews, inspects, and then installs its own fibre and equipment. NBN recommends using an expert designer or installer, but the developer stays responsible for meeting NBN's standards within the property boundary.
Pit and pipe is the build model NBN uses for multiple stand-alone dwellings, adjoined dwellings, horizontal MDUs, super lots and empty lots on newly built roads.
The steps, in order
- 1
Design
The pit and pipe design is prepared to NBN's guidelines. This is the step we do. It sets pit locations and types, conduit sizes and routes, and a service drop to every premises.
- 2
Upload the pre-construct design
The design is uploaded to the nbn New Developments portal for NBN to review and accept. NBN gives feedback if anything needs to change, and we action those comments at no extra charge.
- 3
Build
Your civil or telecommunications contractor installs the pits and conduits to the accepted design, with conduits sealed, draw cords fitted and service drops labelled in each pit.
- 4
As-builts and Notice of Practical Completion
As-built designs and the Notice of Practical Completion are uploaded for NBN to review. With the notice, the developer transfers ownership of the works to NBN, or for a horizontal MDU grants NBN a licence for exclusive use.
- 5
Remediate if required
If NBN's review or inspection finds a problem, the design or the build is corrected and resubmitted.
- 6
Connection boxes and in-home cabling
NBN recommends pre-installing the connection box at each home, ideally at frame stage, and builders supply the in-home cabling to NBN's guidelines.
- 7
Inspection and certificate
NBN inspects the site, issues the Certificate of Practical Completion, works with its delivery partner to install the network, and tells the developer when the site is in service.
What NBN checks in a design
- Only pit types allowed by NBN's standard, placed away from trafficable areas, driveways and swales
- At least 15 m between pits and transformers
- White rigid PVC conduit to AS/NZS 1477, sized for its role: P100 or P50 in the street, P20 to each SDU
- Service drops no longer than 25 m from pit to boundary, with no more than 180 degrees of bends between pits
- Surrounding roads and existing telecommunications pits documented
- A premises count that matches the stage application
For small developments of up to 20 premises, NBN accepts the design as a PDF and its AutoCAD drafting tool is optional. For larger and pathway designs NBN strongly advises using its drafting tool.
Where projects lose time
NBN's own timeframes for review and inspection are outside any designer's control, but most delays we see come from the developer side and are avoidable:
- Incomplete plans. Missing lot boundaries, kerbs or driveway positions mean the design has to be guessed or redone.
- Premises counts that change. If the lot or unit count changes after design, the design and the stage application both need updating.
- Late site changes. A moved driveway or new transformer can push a pit out of compliance.
- Build departing from design. Contractors who change routes or skip draw cords and labels create as-built rework.
Our timelines guide covers what drives our two-week turnaround and the NBN-side stages after it.
Who does the design
The developer is responsible for the design and can arrange it however they like. NBN encourages using an industry professional or an NBN trained new developments supplier so the design is right first time and certification is faster. NBN's training is free, and its trained consultants are listed in NBN's public directory. NBN Design's designer is NBN accredited for SDU and MDU design. See About.
The standards we design to
NBN publishes its requirements as the New Developments pit and conduit standard, NBN-TE-CTO-194, currently Revision 13.0 (August 2026), and the MDU building standard, NBN-TE-CTO-284, currently Revision 16.0. We check the current version before each job.
Process questions
Who uploads the design to NBN?
The design is uploaded through the nbn New Developments portal under your developer account. We prepare the files ready to upload and can guide you through it.
Who owns the pits and conduits after construction?
With the Notice of Practical Completion, the developer transfers ownership of the pit and pipe works to NBN. For a horizontal MDU, the developer grants NBN a licence for exclusive use instead.
When should the connection box go in?
NBN recommends pre-installing the connection box at each home, ideally at frame stage.
What happens if NBN rejects the design?
NBN gives feedback through the portal. We action NBN's comments on our design at no extra charge, unless they result from changes to your development.