Acreage and Hinterland Builds: Water, Power, Access and Effluent

An acreage or hinterland build is an infrastructure project before it is a building project. On a serviced lot at Coolum Beach, water, sewer, power and a kerb crossover already sit at the boundary. On a hectare at Ninderry, Doonan or Belli Park you create all four yourself, and those four decisions — how much water you store, how you treat and disperse effluent, how steep and long the driveway runs, and how power reaches the meter — have to be made before the floor plan is locked. Each takes usable land off the site and reorders the program. Settled during design, an acreage build runs much like any other. Left until after the building approval, they drive the cost and the timeline.

The four infrastructure decisions no coastal build faces

Each of these is a design input, not a site cost to price later.

Water: how much you actually have to store

Two separate numbers apply and people conflate them. Household supply comes first. Business Queensland states that where a local government has been approved to opt in to the Queensland Development Code, the relevant QDC applies to new buildings located on a property within a reticulated town water area. Inside that scope it sets the minimums: for a detached house the tank must have a minimum capacity of 5,000 litres, for a non-detached house 3,000 litres, and all rainwater tanks must receive rainfall from at least half of the available roof catchment area or 100m², whichever is lesser. On unserviced hinterland land, then, 5,000 litres is what the state sets as a supplement to a town main — not a target for a house with no other supply. Your real number comes off roof area, rainfall and household demand, and it is a design calculation, not a code lookup.

Firefighting water is a separate requirement, and on hinterland land it usually bites. For a dwelling house on land mapped in the bushfire hazard overlay, the acceptable outcomes for accepted development in Sunshine Coast Council’s bushfire hazard overlay code provide that where there is no reticulated water supply, the premises has an on-site water volume of not less than 5,000 litres available for fire fighting purposes, provided in a separate tank, a reserve section in the bottom part of the main water supply tank, a swimming pool installed immediately upon construction of the dwelling, or a permanent dam. The code adds a note that water supply capacity for fire fighting purposes is in addition to water supply capacity for household use. Where the premises has an on-site supply it also requires a water supply outlet pipe 50mm in diameter fitted with a 50mm female camlock, which the code calls the standard fire brigade fitting, a hardstand area for fire fighting vehicles within 6 metres of that outlet pipe, and any pumps that pressurise water output able to be operated without reticulated power. Read that last clause twice.

Effluent: the approval that decides where your house sits

Noosa Shire Council states that to install an on-site sewerage treatment facility, including a septic system or an on-site sewage treatment plant, you must first get approval from your local government. Sunshine Coast Council puts the same point as a permit: all on-site sewerage facilities need a plumbing permit, that is an approval, from council before installation.

A treatment plant carries a second approval on top of that. Business Queensland states that a treatment plant approval is required in accordance with the Plumbing and Drainage Act 2018, that the Department of Housing and Public Works issues chief executive approvals for on-site sewage treatment plants capable of treating no greater than 4.2kL of sewage in a day, and that the Department of the Environment, Tourism, Science and Innovation issues approval for systems treating sewage from 4.2kL or more. Business Queensland also states that a septic only or primary system does not require a treatment plant approval. A single dwelling sits well under the 4.2kL threshold either way, so for a house the practical question is which type of system you install, not which department you end up in front of.

Sunshine Coast Council describes an on-site sewerage facility as two components: the treatment plant, and the land application area. Before selecting one you must have a licensed site and soil evaluator visit the property, who will conduct an investigation and recommend the level of treatment required. The council identifies three land application types — trench based systems transpiring to large flat areas with absorbent soils, surface irrigation systems dispersing through sprinklers, which it notes may not be suitable for sloping land, and sub-surface systems dispersing through pipes beneath a layer of suspended soil. On the plant itself, Noosa Shire Council states that septic tanks need to be constructed and approved in accordance with AS/NZS 1546.1 2008, and Business Queensland references AS1546.3:2017 for treatment plants.

The consequence is blunt. The evaluation returns a land application area of a set size in a set place, and that ground is dead: no house, no shed, no pool, no driveway, no heavy vehicle traffic. Where a rural lot carries a nominated building envelope, the Rural zone code in the Sunshine Coast Planning Scheme 2014 gives as an acceptable outcome that clearing of native vegetation and building works do not extend beyond the building envelope, except for the purposes of a driveway access — and that same code lists on-site effluent disposal among the impacts the outcome guards against. Book the evaluation before you commission the design. It reaches later work too: under schedule 9 of the Planning Regulation 2017, a development application for building work for a class 1 building, where an on-site wastewater management system as defined under the Queensland Plumbing and Wastewater Code has been installed on the premises and the work involves adding one or more bedrooms, requires referral to the local government, assessed against the Queensland Plumbing and Wastewater Code, part 1, performance criteria P2.

Access: the driveway is a civil job, not a strip of concrete

Sunshine Coast Council states that section 75 of the Local Government Act 2009 requires council approval for work undertaken on roads including the road reserve or nature strip area, and that for a non-standard crossover construction must not start until you have the final approval notice from council. Where there is no kerb and channel — most hinterland frontage — the council points to standard drawings RS-049, RS-050 and RS-056 for rural driveway design. Where the property takes access from a state-controlled road, approval comes from the Department of Transport and Main Roads rather than council. The council is also clear that the property owner is responsible for construction and maintenance, including any associated drainage and kerbing and any affected footpath, water course, drain or drainage easement.

There is no single statutory maximum grade for a private driveway. What the bushfire hazard overlay code does give you is the benchmark council uses to judge emergency access. In its performance and acceptable outcomes for assessable development, roads are to have a maximum gradient of 12.5%. Fire breaking trails, where development involves creating a new road, are to be located along and within a cleared road reserve having a minimum width of 20 metres with a maximum gradient of 12.5%; where development does not involve a new road, trails are to have a cleared minimum width of 6 metres, a maximum gradient of 12.5%, continuous access for fire fighting vehicles, vehicle access every 200 metres, and passing bays and turning bays every 400 metres. Those outcomes are aimed at subdivision and new roads rather than at one house on an existing lot, but they tell you plainly what this council treats as trafficable when a fire is running. The same code asks that residential lots be designed so their size and shape allow for efficient emergency access to buildings and for fire fighting vehicles, giving battle-axe or hatchet lots and long narrow lots with long access drives to buildings as the examples to avoid.

Construction traffic asks the same questions. A long, steep or tightly curved drive decides whether an agitator reaches the slab, whether a truss delivery can turn around, and whether a pump is hired for every pour. Culverts and table drains matter as much: a drive that scours out in the first storm is a delay on your own job. Where the fall is significant, the earthworks overlap with our guide to building on a sloping block in Queensland.

Power: reticulate, or go without

Power is the long-lead item and there is no published price for it. The distribution network provider quotes each rural connection individually against distance to the nearest network, overhead versus underground, whether new poles, easements or a transformer are needed, and the load requested. Ask for that quote the week you settle, not the week before the frame goes up. Everything downstream of the point of supply is wired to AS/NZS 3000 Electrical installations, the Wiring Rules. On a genuinely remote block a stand-alone power system, the subject of AS/NZS 4509, can beat a long network extension, but that comparison needs an electrical load schedule early. Without temporary site power, trades run off generators, and that shows in productivity long before it shows on an invoice.

Bushfire, soil and getting the contract right

Business Queensland records that Queensland Development Code MP 2.4, Construction in bushfire prone areas, was repealed on 14 April 2015. Bushfire construction now reaches you through the building assessment provisions read with the planning scheme overlay mapping. Sunshine Coast Council’s bushfire hazard overlay code notes that the Building Code of Australia contains provisions applying to building in bushfire prone areas, and that designated bushfire areas for the purposes of the Building Regulation and the BCA are identified as medium or high bushfire hazard areas or bushfire hazard area buffers on the bushfire hazard overlay maps in schedule 2 of the scheme. In Noosa Shire the equivalent instrument is the Noosa Plan 2020, which Noosa Shire Council describes as comprising a strategic framework, local plans, zones and overlays, tables of assessment, development codes, planning scheme policies and the local government infrastructure plan. Where a bushfire attack level assessment applies, the construction requirements come from AS 3959 Construction of buildings in bushfire-prone areas, and the assessed level changes windows, screening, decking, subfloor detailing and eaves. That belongs in the brief, not in a variation. Footings are designed to AS 2870 Residential slabs and footings off a site classification, and hinterland reactive clay behaves nothing like coastal sand.

The contract then has to say who carries what. The QBCC states that you need a written contract if you are carrying out domestic building work priced over $3,300 including labour, materials and GST, that a Level 1 contract covers contracts priced at $3,301 to $19,999 for renovations, extensions and routine repairs on existing homes, that a Level 2 contract covers contracts priced at $20,000 and over, and that where the work is priced at $20,000 or more the building contractor must give the owner a copy of the QBCC consumer building guide before the owner signs. List the crossover, the effluent system and its land application area, tanks, pumps and the firefighting reserve, the network connection and any bushfire-driven upgrades separately. Where a figure genuinely cannot be fixed, a documented provisional sum beats a number that will move, as our guides on building costs on the Sunshine Coast and fixed-price building contracts in Queensland explain.

Roebuck Concepts holds QBCC licence 15280811 and works across the Sunshine Coast and Noosa Shire from Coolum Beach, including hinterland work at Elouera Drive, Ninderry. Our new home builds page sets out how we run the process from site investigation to handover.