The information relates to the following two sections of the Deployment of nbn™ Conduit and Pit network guideline (NBN-TE-CTO-194):
- 4.8.5 Super Lot Pit and Conduit internal reticulation.
- 4.8.6 Barrier Kerb.
What is a Horizontal MDU?
Horizontal Multi Dwelling Units (Horizontal MDU) in a new development refer to a group of units, townhouses or factories built within the boundary of a large piece of land/Super Lot e.g. gated communities, retirement villages. This could also refer to an existing estate/suburb where a Horizontal MDU is built as a result of a knockdown/rebuild (also referred to as infill areas).
A Super Lot is a parcel of land with no actual dwellings built on it, but rather just land being prepared with pit and pipe to be set aside for future development.
Size of Horizontal MDU developments
To assist developers and their external design consultancies, and to ensure there is no over engineering when working out the amount of pit and pipe required for each premises, nbn deliberately separates the size of Horizontal MDU into two distinct groups – these are:
Horizontal MDU: 4 to 24 premises
Smaller Horizontal MDU require a minimum P50 conduit as the main conduit reticulating through the development, this includes P5 and P2 pits as the minimum requirement. The internal pit and pipe reticulation would be similar to either single or dual sided installation.
Horizontal MDU: 25 or more premises
Larger Horizontal MDU would require a minimum P100 conduit as the main conduit reticulating through the development. Depending on the size of the Horizontal MDU, this may include P8, P5 and P2 pits. P9 pit/s may also be required to support FDH/s. The internal Pit and Pipe reticulation would be similar to either single or dual sided installation.
Things to consider before design and install
- A Barrier Kerb can be used in either scenario to protect pits inside the development area from vehicular traffic. Note a Barrier Kerb is not to be used in the road reserve (nature strip) outside of the development.
- The preference for pit installation is within common areas, landscaped areas, and internal footpaths.
- Developers are responsible for providing connectivity to each premises - both internal and street facing.
- Generally, the street facing premises could be fed via the internal pit and pipe providing Deployment of nbn™ conduit and pit network guidelines (NBN-TE-CTO-194) are met. If a Horizontal MDU contains a percentage of street frontage premises that have limited or no existing pit and pipe in the adjacent road reserve outside of the development (see Figure 1), then the developer must ensure the internal pit and pipe continues out into the road reserve. In these situations, the development boundary will encompass the external pit and pipe as part of the overall development pit and pipe design.
Figure 1: Horizontal MDU with street frontage and internal premises containing developer installed pit and pipe.
- All residential premises must have an individual nominal P20 conduit installed from a pit attached to each premises.
- All factories or light commercial premises must have a minimum P50 conduit installed from a pit attached to each premises.
- Where there is limited existing nbn pit and pipe available in the road reserve (outside of the development boundary) to service the street fronting premises, additional pits and service drop conduits will be installed by nbn over the existing network and funded by the developer (see Figure 2, 3, 4). The developer must install the lead-in conduit from the street facing premises to the development boundary to complete connectivity.
Figure 2, Figure 3, Figure 4: For Horizontal MDU developments reflecting internal pit and pipe and street facing premises require the installation of additional
Health and safety
Health and safety must be taken into consideration when deciding the pit locations within an Horizontal MDU development. Pits are not to be installed in any area that is open to traffic. These include:
- Vehicular access ways
- Turning circles
- Car parks including wash bays
- Bin storage areas