NBN pit and pipe design: common questions
Short answers about pit and pipe design, NBN's rules for SDU and MDU developments, and working with NBN Design. Each answer links to a fuller guide.
Reviewed 14 October 2026 against NBN's published standards
The basics
What is NBN pit and pipe design?
It is the design of the underground pits and conduits that carry NBN fibre to each premises in a new development. NBN reviews the design before construction starts. See how the process works.
Who needs a pit and pipe design?
Developers of new developments that NBN services through pits and conduit. NBN lists multiple stand-alone dwellings, adjoined dwellings, horizontal MDUs, super lots and empty lots on newly built roads as examples.
Do I have to use a trained or accredited designer?
No. The developer is responsible for the design and can arrange it themselves. NBN encourages using an industry professional or an NBN trained supplier so the design is right first time.
What is the difference between an SDU and an MDU?
An SDU is a single dwelling unit on its own lot, such as a house in a subdivision or each dwelling in a duplex, and each gets its own P20 service drop conduit. An MDU has multiple dwellings within one lot, such as an apartment building or townhouses on common property. See SDU or MDU.
Which NBN standard applies?
NBN's New Developments pit and conduit standard, NBN-TE-CTO-194, currently Revision 13.0, and for buildings the MDU building standard, NBN-TE-CTO-284, currently Revision 16.0.
NBN's design rules
How many lots can one NBN pit serve?
NBN's standard allocates typically four lots, and up to eight, to a service drop or boundary pit, within the conduit limits for that pit type. See pits and conduit.
How long can a service drop conduit be?
The furthest service drop run from a pit to the property boundary entry must not exceed 25 m.
How far must a pit be from a transformer?
At least 15 m from pad-mounted transformers and poles with transformers, and at least 3 m from other poles.
What conduit does an apartment building need?
One P50 lead-in for 2 to 60 premises, and one P100 or two P50 lead-ins above 60 premises. See MDU design.
How deep does NBN conduit go?
Service drops need 300 mm of cover when the run is under 3 m and 450 mm when longer. Verge conduit needs 450 mm and conduit under roads 600 mm.
Working with us
Who will design my project?
Michael Almond, NBN accredited for SDU and MDU pit and pipe design (enAble ID 439386). See About.
Do you work outside NSW?
Yes. NBN's new developments process is national, and we take projects in every state and territory.
What do you need to give a quote?
The site address, development type, number of lots or dwellings, and your NBN application reference if you have one. CAD (DWG) and/or PDF plans are needed before work starts.
Do I need an NBN application first?
No. You can ask for a quote before an application exists. Tell us the reference if you have one.
How long does the design take?
Plans are turned around within two weeks of receiving complete CAD plans. Poor quality CAD or difficult sites can add time, and we tell you up front. See timelines.
What file formats can I send?
CAD (DWG) and PDF. Send a share link in the quote form, or we will send an upload link when we reply. See preparing CAD plans.
What do I receive?
The design as a PDF ready to upload to NBN's portal, the AutoCAD DWG file, and the as-built design after construction. See the design package.
What if NBN asks for changes?
We action NBN's comments on our design at no extra charge, unless they result from changes to your development. One revision requested by you is also included.
Pricing
How much does it cost?
From $120 per unit, with lower rates at 11, 26, 51 and 101 units. A 30 unit development is $3,295. Use the calculator for an estimate. Quotes are free.
Is there a minimum fee?
No. A duplex is two units at $120, $240 in total.
Do you offer any add-on services?
Yes: NBN application concierge ($250 per stage), rush turnaround within 5 business days (+30% of the design fee), as-built design only for networks designed by others ($50 per unit), and a fixed-price duplex package ($450). See add-on services.
When do I pay?
We invoice when the draft design is complete, with payment due within 30 days.