Demolition Before a Basement Build in Brighton

Basements have become a regular feature of new homes in Brighton, Brighton East and Hampton. On a valuable Bayside block, going down is often the simplest way to add a garage, a cellar, a gym or a media room without giving up garden or running into height limits. If your new design includes one, the demolition that comes before it is a slightly different job from a standard knockdown, and getting the handover right saves time and money once the excavation contractor arrives.

Demolition and excavation are two different scopes

The most common source of confusion on basement projects is where the demolition finishes and the excavation begins. A standard demolition takes the house, outbuildings, slabs, footings and paving out and leaves the block cleared and level for a builder to set out. A basement build then removes a large volume of natural ground, usually behind engineered retention such as piling or shoring that has to go in first.

Those are different trades with different machines, different engineering and often different contractors. Before we price the job, it helps to know who is doing the bulk excavation and what they expect to receive. Some builders want every slab and footing removed and the block left flat. Others prefer that old slabs or hardstand stay as a working platform for the piling rig, to be broken out with the excavation. Neither is wrong, but the quote and the program should say which one applies, so nothing is paid for twice or left for nobody.

Sandy ground and what it means

Much of Brighton and the bayside suburbs to the south sit on sandier profiles than the clay sites further inland. Sand behaves differently when it is opened up: excavation faces are less stable, and it does not hold a vertical cut the way stiff clay can. For a demolition that mainly matters when slabs, footings, cellars or an old pool shell are removed, because each leaves a hole that has to be backfilled and compacted or left in a state the basement design allows for.

Groundwater can also be a factor on some low-lying sites closer to the bay. Whether it is, and how it will be managed during the basement dig, is a question for your geotechnical engineer and builder rather than the demolisher, but it is worth knowing early, because it can influence the order in which things happen on site.

Geotechnical investigation and survey timing

Your engineer will usually want a geotechnical investigation, typically boreholes or test pits, to design the basement retention and footings. Sometimes those can be drilled with the house still standing, in the driveway or rear yard. Sometimes the engineer wants them in the footprint of the old house, which means after demolition. The same goes for a fresh feature and level survey. If either has to happen between demolition and excavation, build that gap into the program so the site is not sitting idle while bookings are made.

Neighbours, boundary walls and protection work

A basement digs deep close to the boundary, and that is where the neighbours' interest is greatest. Your building surveyor will decide whether protection work notices are needed for the adjoining properties, and most basement projects on tight Bayside blocks include a dilapidation report of the neighbouring homes before any machine starts. Commissioning it before demolition, rather than before excavation, protects you across both stages. Our article on dilapidation reports before demolition explains how that works.

Boundary garages, shared fences and boundary walls also need a decision at demolition stage: whether they come out now, stay until the piling goes in, or are retained altogether. That is a conversation with your builder and engineer, and we plan the demolition around their answer.

Spoil, trucks and the street

A basement generates a great deal of soil on top of the demolition waste, and all of it leaves by truck. Demolition material is separated for recycling, while excavated soil usually needs testing and classification before it can go to a receiving site. On a busy Brighton street, the two stages together can mean weeks of truck movements, so the asset protection permit, crossover protection and any traffic management arranged for the demolition should be set up with the excavation in mind as well.

Trees and services

Tree protection zones shown on your planning permit apply through both stages, and a basement can come much closer to a retained tree than a slab-on-ground home, so the protection fencing we install needs to suit the excavation layout too. Service abolishment is the same as for any knockdown, but new connections for a home with a basement may enter the site in a different place, so tell us where your builder expects them so the old ones are cleared from the right spots.

How we handle a basement project

On these jobs we quote and program the demolition as the first stage of a two-stage clearance. That means agreeing the handover level with your builder, removing what the excavation contractor needs gone, leaving what they want left, protecting the boundaries and retained trees, and getting service abolishment and the dilapidation work done early. Our Knockdown-Rebuild Site Preparation service covers the standard handover, and Permits and Heritage Approvals covers the paperwork if your property also sits under an overlay.

If you are planning a Brighton, Hampton or Brighton East rebuild with a basement, send us the address and your builder's or engineer's drawings. We will inspect, confirm the scope boundary with your builder, and give you a fixed price that fits the basement program rather than fighting it.