Project Update

It's been a couple of weeks since the last video because visually not much has changed on site—mainly cars shifted around. That doesn’t mean nothing has been happening. Most of the work lately has been paperwork and coordination to move into early works.

DA approved and next steps

We just received the Development Approval (DA) last week. Its conditions were straightforward, so I reviewed them and passed the requirements to our consultants: hydraulic, structural, electrical engineers, and the architect. No major issues in the DA conditions, which is good.

Now the priority is assembling the early works building approval pack so we can get building approval. The structural engineer needs to provide the Form 15 and completed design for the basement slab, basement walls and building over sewer detail.

Because we’re using sheet piling as the retention system, we need the sheet piling design too—but that requires the contract and construction insurance to be in place first.

Insurance and contractor coordination

We’ve requested construction insurance quotes from our brokers. One quote we received was unacceptably high, so we’re waiting on the broker to find a better option. Once insurance is secured and the contract is final, we’ll submit everything to the sheet piling company and proceed with temporary installation.

We’ve booked a temporary installation date for sheet piling. We’ll separate the sheet piling works from the dewatering installation, which the piling contractor is fine with. The piling runs continuously around the site, under the driveway, and along the boundaries. Continuity is critical because groundwater sits beneath the site—if the dewatering pump or backup power fails, the piling must hold water in until it can be pumped out.

Dewatering plant and power setup

The sheet piling company confirmed dewatering plant sizing: roughly 7 m x 3 m and about 52 tonnes. The dewatering plant requires a three-phase, four-pin, 50 A circuit; the pump runs on a 10 A circuit. Both feeds will run back to the meter box—less than 10 meters away from the plant location—so we’ll have an electrician install another three-phase outlet on the meter box.

We’ll also bring a diesel generator with an auto transfer switch as backup. If mains power fails, the generator will automatically kick in to keep the dewatering system operational.

Technical checks and plans

I’ve sent geotechnical reports and the dewatering management plan to the sheet piling company; we’re still waiting on the vibration management plan. We’ll monitor vibration at two neighbouring houses during piling to avoid disturbing neighbours—the goal is to keep good relations while complying with controls.

Site clearing and excavation

We removed more of the crossover and hardstand to make way for piling. I’ve been digging to expose top-of-piling levels so the contractor can install piles down to the nominated reduced level (RL). We set an RL of 2.8 m for the piling top so it won’t need trimming later—cutting sheet piling post-install is costly and inefficient.

Small excavations with a three-ton machine cleared the pile alignment and let us confirm finished floor levels. The excavations also create access for piling in tight spots and help locate the top of the piles accurately so backfilling will restore final landscaping heights later.

Neighboring boundary walls and structural strategy

During demolition we discovered remnants of old concrete and damaged boundary walls—some sections were already leaning. We’ll remove these sections and rebuild them correctly. The structural engineer and I have discussed how to rebuild the walls and form new footings.

Boundary Wall Plan Summary:

  • Remove failing wall sections along the side boundaries.
  • Extend the basement slab out to the boundary.
  • Form a large footing at the base and build a retaining wall back up. In one tighter area, we may use strip footings initially; the main issue is the piling machine’s proximity to the neighbor’s wall—about 600 mm. We need to ensure there’s enough space to complete excavation and concrete works. We may use the sheet piling as temporary formwork for footings if clearances allow.

Consultants and approvals

There’s ongoing back-and-forth with consultants. The structural engineer is waiting on some architectural details; the architect’s progress has been slower than ideal but everyone’s busy. Ideally some of this architectural detail would’ve been done earlier to speed structural design, but we’re working through it.

To complete the early works Building Approval (BA) pack we need:

  • Form 15 from hydraulics and other specialist designs (completed or in progress)
  • Civil, structural documents
  • Insurance, QBCC & Qleave details (already started)

We also need a building over sewer structural design before submitting to council. Once the pack is complete we’ll lodge it and expect a roughly 30-day turnaround for approval. Note: certifiers have changed how they handle building-over-sewer approvals and many don’t take that liability anymore, so we prepare and submit documents directly and wait for their response.

Other small updates

  • Demolition cleanup: removed leftover concrete and finished some side excavations.
  • Trialed sandbags on site for non-construction testing purposes.
  • We’ve parked diesel and petrol vehicles and are running EVs due to rising fuel costs. At current prices, a 140 L tank at $4/L would be $4/Lwould be $560.
  • We’re seeing about $100 in electricity to cover the same kilometers for a long-range EV—considerable savings.
  • Minor site notes: the portable toilet remains pink; the barbecue is still on site.

Summary

There’s a lot of paperwork and coordination right now: insurance, contractor contracts, engineering details, and approvals. The visible site work will ramp up when sheet piling and de-watering begin—we’ll film that phase and share another update. For now, it’s steady progress behind the scenes.