Demolition contractor on a residential job: scope, licensing, HRCW, and asbestos

TL;DR

A demolition contractor knocks down and clears structures: residential knockdowns take 2 to 5 days on the tools, but the total process from engagement to site ready for excavation runs 4 to 8 weeks once approval, asbestos pre-demolition survey, services disconnection, and council notification are factored in. Typical cost for a standard single-storey house in Sydney is $20,000 to $45,000 ex-GST, with asbestos adding $5,000 to $15,000 on pre-1990 homes. In NSW, demolition of load-bearing or structurally integral elements is High-Risk Construction Work (HRCW category 3) and requires a SWMS; demolition at 6 m or above also triggers written notification to SafeWork NSW at least 5 days before work starts. The biggest job-killer is asbestos discovered after mobilisation: an independent clearance certificate must be issued by a licensed asbestos assessor before demolition proceeds, and the site cannot be handed to the builder until it is.

What this trade covers

The demolition contractor manages the dismantling, pulling down, and site clearance of existing structures. On a residential knockdown-rebuild or site-prep job, scope typically includes:

Full structure demolition: removing all above-ground elements of an existing dwelling, including the roof, frame, masonry, subfloor, and slab (if required). Most knockdown-rebuild jobs leave the existing slab in place if it is in good condition and the new build can use it, saving $3,000 to $8,000 on removal and disposal.

Selective or partial demolition: removing specific elements while the rest of the structure remains. A common example is removing a rear wing or garage to make way for an extension. Structural alterations requiring temporary support are HRCW category 5 and need their own SWMS.

Site clearance and clean-up: demolition waste is classified. Concrete, brick, and timber go to different disposal streams; some can be crushed and reused as fill subject to EPA requirements. A Waste Management Plan (WMP) is often a council DA condition.

Utility disconnection coordination: before any demolition starts, water, gas, electricity, sewer, and telecoms must be disconnected and capped by the relevant authority or licensed trade. This is the demolition contractor’s coordination responsibility; the disconnections themselves are each trade’s scope. Service disconnection adds $3,000 to $6,000 and takes 2 to 4 weeks to book in (verified 2026-05-10).

What’s in scope (typical residential)

Full knockdown of single or double storey Class 1 dwellings
Slab removal (if specified in the contract)
Garage, outbuilding, and ancillary structure removal
Asbestos removal coordination (contractor holds Class A or Class B licence, or sub-contracts to a licensed removalist; asbestos-containing material is ACM)
Waste classification, sorting, and disposal to licensed facilities
Waste Management Plan compliance per council DA conditions
Neighbour notification per CDC or DA conditions
Post-demolition site levelling and rubble clearing
Independent asbestos clearance certificate (must be issued before handing site to builder)

What’s out of scope (often confused)

Structural engineering design for partial demolition: if selective demolition requires temporary support or shoring, engineering input is the structural engineer’s scope. The demolition contractor constructs to the engineer’s temporary works design.
Services disconnection: the contractor coordinates booking dates and confirms disconnection is done, but does not hold the licence to disconnect gas, electricity, or sewer connections. These are licensed trade scope.
Ground contamination remediation: soil contamination from underground storage tanks, asbestos in fill, or chemical spill is a specialist environmental remediation scope. The demolition contractor may identify the risk; treatment is not in their standard brief.
Excavation below existing slab level: earthworks, cut-and-fill, and bulk excavation for the new build are excavator contractor scope, sequenced after demolition is complete and cleared.
Tree removal: trees are typically arborist or landscaper scope, subject to council tree preservation orders and separate permit conditions.

Approval pathways

Demolition in NSW can proceed via two pathways.

Complying Development Certificate (CDC): for standard residential demolition that meets the criteria in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 (NSW), a CDC via a private certifier is faster than a DA and typically takes 2 to 4 weeks for approval. The CDC pathway requires neighbour notification at least 7 days before work starts (verified 2026-05-10).

Development Application (DA): required where the property is in a heritage conservation area or draft heritage conservation area, or where demolition does not meet CDC criteria. DA assessment can run 3 to 6 months for residential work (verified 2026-05-10).

Both pathways trigger a condition requiring all asbestos to be removed and an independent clearance certificate issued before demolition proceeds on pre-1987 buildings, and on any residential structure built before 2004 where asbestos-containing materials are suspected.

Verify current approval pathways with the NSW Planning Portal or your private certifier before engaging a demolition contractor, as SEPP and council DCP conditions vary by site.

HRCW obligations

Demolition work on a residential job will trigger at least two HRCW categories under WHS Regulation reg 291:

Category	Description	What it means on a demolition job
3	Demolition of a load-bearing or structurally integral element	Every standard knockdown triggers this. A SWMS must be prepared before work starts.
4	Work likely to disturb asbestos	Any pre-1990 building warrants an asbestos identification check before touching anything.
1	Risk of a person falling more than 2 m	Working on roofs, elevated slabs, or upper floors during partial demolition.
5	Structural alterations requiring temporary support	Selective demolition involving shoring or propping.

Source: Work Health and Safety Regulation 2017 (NSW) reg 291 (verified 2026-05-10).

Notifiable demolition work: under WHS Regulation reg 296, if the work involves demolition of a load-bearing or structurally integral element that is 6 m or more in height, the PCBU must give written notice to SafeWork NSW at least 5 days before work starts. Most double-storey residential demolitions and all commercial demolitions trigger this requirement (verified 2026-05-10).

Engagement basics

Licensing, state-by-state

NSW has two demolition licence classes administered by SafeWork NSW, separate from the building contractor licence held by the principal contractor.

Licence class	Scope	Height limit
Restricted demolition licence	Load-bearing or structurally integral elements on structures 6 to 15 m; load-shifting machinery on suspended floors (e.g. excavator on elevated slab)	Up to 15 m
Unrestricted demolition licence	All of the above, plus structures over 15 m, chemical installations, tower cranes, mobile cranes over 100 t rated capacity, pre-tensioned or post-tensioned elements, explosives	No height limit

Both classes require an approved named supervisor who has completed units from the Certificate III and Certificate IV in Demolition, and who can demonstrate hands-on experience across relevant demolition types. Licence duration is 5 years (verified 2026-05-10 via SafeWork NSW).

Most single and double-storey residential demolitions fall within the restricted licence scope. Confirm the contractor holds a current licence before engagement; check via Verify NSW.

State	Demolition licence body	Notes
NSW	SafeWork NSW (restricted / unrestricted)	Separate from builder’s contractor licence
VIC	WorkSafe Victoria	Demolition work licence required
QLD	QBCC	Demolition licence under the QBCC framework
WA, SA, TAS, NT, ACT	Each state/territory regulator	Verify current licence class and requirements before engaging

AS 2601-2001 (The Demolition of Structures) is the national standard for demolition planning and execution. It must be on site for all demolition work except fences and walls under 1.8 m or structures under 2 m in height (verified 2026-05-10).

Asbestos licence requirements

Asbestos removal is a separate licence from the demolition licence. Two classes apply in Australia:

Class	Scope	Trigger threshold
Class B asbestos removal licence	Non-friable asbestos-containing material (ACM) only	Required for removal of more than 10 m2 of non-friable ACM
Class A asbestos removal licence	Both friable and non-friable ACM, including friable fire doors and safes	Required for all friable asbestos

Many demolition contractors hold both a demolition licence and a Class B or Class A asbestos removal licence. If the contractor does not hold the required asbestos licence, they must sub-contract the asbestos removal to a licensed removalist before demolition can proceed. The asbestos clearance certificate must be issued by an independent licensed asbestos assessor (not the removalist) before the site is handed back (verified 2026-05-10 via SafeWork NSW).

Pre-demolition asbestos survey

For any residential structure built before 1990, or any structure where asbestos-containing materials are suspected, a pre-demolition asbestos survey is mandatory before demolition proceeds. The survey is a destructive investigation of concealed areas: wall cavities, roof spaces, subfloor voids. A licensed asbestos assessor conducts the survey and produces an asbestos register identifying type, location, condition, and quantity of all ACM (verified 2026-05-10).

Asbestos adds $5,000 to $15,000+ to the total cost depending on quantity and type (friable asbestos is significantly more expensive to remediate than non-friable). The demolition contractor should sight and price against the survey report before quoting; surprises discovered after mobilisation become variations.

Insurance the demolition contractor should carry

Public liability: minimum $10m for residential knockdown work; $20m where the site is adjacent to shared structures or in a dense urban environment
Workers compensation: required for all employees
Construction works / contract works insurance: some clients require this on knockdown-rebuild packages; confirm with the building contract
Professional indemnity: required only for demolition contractors who provide engineering advice or design services (not standard for knockdown work)

Sight current Certificates of Currency for public liability and workers compensation before engagement.

Pricing basis

Demolition is typically priced as a lump sum per job, not a day rate or square metre rate. The lump sum covers:

Mobilisation and site establishment
Asbestos pre-demolition survey and (if applicable) removal by a licensed removalist
Physical demolition and deconstruction
Waste classification, removal, and disposal
Site levelling and rubble clearing
Clearance certificate from an independent licensed assessor

Get at least two quotes. Prices for a standard single-storey dwelling in Sydney range from $20,000 to $45,000 ex-GST; double-storey and asbestos-positive jobs push to the upper end. A quote significantly below the market range should raise the question of whether asbestos is priced in and whether the contractor holds the required licences (verified 2026-05-10).

Tolerances and acceptance

Demolition is a process, not a finished workmanship trade. There are no workmanship tolerances in the HIA Guide or state Guides that apply to demolition output in the way that plasterboard flatness or mortar joint width would apply.

What is inspected and accepted at handover is:

Asbestos clearance certificate: an independent licensed assessor must certify the site is clear of asbestos before it can be handed to the builder. This is a binary pass/fail; the certifier inspects and either issues or does not.
Site level and rubble clearance: all debris, rubble, and remnant materials removed to specified tolerance (typically within 150 mm of final design level, unless earthworks specification is tighter); no structural elements left standing unless explicitly agreed in the scope.
Utility cap-offs: all disconnected services must be capped and signed off by the relevant authority or licensed trade before demolition starts; copies of sign-offs form part of the site handover package.
Waste Management Plan compliance: a WMP is a DA condition on most demolitions; documentary evidence of compliant disposal (receipts from licensed facilities) forms part of the DA compliance record.

Common defects and problems to look for

Asbestos discovered after mobilisation: the most expensive variation on a demolition job. Undisclosed or unsurveyed asbestos found after the contractor is on site becomes a scope change. The pre-demolition survey is your insurance; pay for the thorough destructive version.
Unlicensed demolition or asbestos work: the cheapest quote may not hold the required licences. Unlicensed demolition and asbestos removal expose the principal contractor to WHS prosecution and regulatory action.
Services not disconnected at start date: if the builder has engaged the demolition contractor as a subcontractor, the builder is responsible for ensuring services are disconnected before the contractor mobilises. A contractor on site with live gas or electricity cannot commence; the delay is a builder-side variation risk.
Clearance certificate delay: the independent asbestos clearance inspection must be booked and the certificate received before site handover. Allow 5 to 10 business days after asbestos removal is complete.
Slab in worse condition than expected: if the slab is to be retained for the new build, its condition should be assessed before demolition. Discovering a cracked or contaminated slab after the house is demolished is a cost that falls on the builder.
Neighbour notification missed: CDC and DA conditions typically require written notice to adjoining owners at least 7 days before demolition. Missing this is a condition breach; some neighbours use it to delay the start.

Subbie quote pack, what should be in it

A complete demolition quote covers:

Scope: what structures are being demolished and cleared; whether the slab is included or retained; tree removal (in or out); garden walls and fences (in or out)
Asbestos: whether the pre-demolition survey is in the quote, who conducts it, who removes any identified ACM, what licence class the removalist holds, and who provides the independent clearance certificate
Approval: whether the contractor assists with the CDC or DA application, or whether the principal contractor handles this separately
Services: which disconnection bookings the contractor coordinates; which are the principal contractor’s responsibility
Waste management: where debris goes; whether a Waste Management Plan is included; disposal receipts provided on completion
Licences: demolition licence class (restricted or unrestricted), asbestos licence class (A, B, or not held), both with licence numbers for verification
Insurance: public liability coverage limit and workers compensation; Certificates of Currency attached
Pricing: lump sum with clear inclusions and exclusions; variation rate for unscoped work (e.g. additional asbestos found, change to slab demolition)
Programme: start date, estimated duration, clearance certificate turnaround, site handover date to builder

The same list reads from both sides:

For the engaging builder or client: this is the quote template. Don’t sign a demolition contract without all items confirmed.
For the demolition contractor quoting: providing all of these upfront wins jobs and reduces disputes.

References

AS 2601-2001: The Demolition of Structures (Standards Australia) (verified 2026-05-10)
SafeWork NSW: Unrestricted demolition licence (verified 2026-05-10)
SafeWork NSW: Restricted demolition licence (verified 2026-05-10)
SafeWork NSW: Class A asbestos removal licence (verified 2026-05-10)
SafeWork NSW: Class B asbestos removal licence (verified 2026-05-10)
SafeWork NSW: Demolition (verified 2026-05-10)
NSW Planning Portal: Demolition (Complying Development) (verified 2026-05-10)
Work Health and Safety Regulation 2017 (NSW), reg 291 (HRCW definition) and reg 296 (notifiable demolition work) (verified 2026-05-10 via SafeWork NSW)
Safe Work Australia, Demolition Work Code of Practice (February 2016), safeworkaustralia.gov.au (verified 2026-05-10)