Excavation Central Coast NSW: what to sort out before the digger arrives

Depth and distance from the boundary come first

The first question a designer or certifier will ask is how far down you are going and how near the fence line sits. Central Coast Council's rules for dwelling houses and ancillary development cap excavation for the purposes of development at 1m below existing ground level when it is less than 1m from any boundary. Move further in, to more than 1m from the boundary, and the cap lifts to 3m.

That is a council planning control, not a rule of thumb, so a cut for a shed slab, a pool or a lowered yard has to be measured against it before anyone starts. If your plans need more depth than the control allows, you are looking at a different approval conversation rather than a quick job.

Fill works the other way. The same council document says fill to support a dwelling must not exceed 1m above existing ground level. If a sloping block means you are cutting on one side and building up on the other, both numbers matter.

Easements and unstable ground can change the plan

Check your title and the survey for drainage easements. Central Coast Council's floodplain and water cycle chapter says no excavation is permitted within 2 metres of any drainage easement unless the Director City Services has granted approval. A backyard that looks wide enough on the day can lose a lot of usable room once that strip is taken out.

Ground stability is the other big one on hilly or sandy coastal blocks. Under the council's geotechnical chapter, a lot assessed at Hazard Category 2 or above needs the development application supported by a geotechnical report covering stability on the site and on neighbouring lots. At Hazard Category 4 the council asks for a comprehensive geotechnical report. Budget for that report before you lock in a start date, because the earthworks design often depends on it.

Allow for the approval wait

If the work needs a development application, time is the cost people underestimate. Central Coast Council says it is "currently experiencing longer processing times for development applications." The council's page says assessments have averaged 88 days over the last 12 months. That is a council-wide average, so your own job could be quicker or slower, but it is a sensible planning figure for when to lodge.

The council's site waste chapter also says a Resource and Waste Management Plan must be submitted and approved as part of the application for each new development on the Central Coast. Spoil from excavation is part of that conversation, so know roughly where the dirt is going.

Some work can skip the full application route. The council lists below-ground swimming pools as an example of complying development, and says a private principal certifier or the council can grant a Complying Development Certificate. Whether your site qualifies depends on the specific controls, so ask a certifier early.

Driveways, demolition and the neighbours

Excavation often comes bundled with a new driveway. The vehicle access crossing is the part of the driveway running across the nature strip, and Central Coast Council says approval must be obtained from it to build a new crossing or alter an existing one, with or without kerb and gutter. Sort that approval separately from the works on your own block.

If a shed, garage or old pool has to come out first, the NSW Planning Portal says you need to notify your neighbour or neighbours before beginning demolition work. For complying development more broadly, it says you must notify neighbours within 20 metres from the boundary of the development lot prior to any work commencing.

Older buildings may carry asbestos. SafeWork NSW says it must be notified 5 calendar days before licensed asbestos removal work starts, which is another reason not to leave demolition to the last minute.

When you are ready to talk through a job, enquiries can be passed on so you can compare what a contractor says about your block against the rules above.