WA Guide

Renovation vs New Build (WA owner-builder)

The “owner-builder” steps are similar — but renovations introduce extra risk areas: existing structures insurance, staging constraints, and “what’s hidden” behind walls.

Compare Common pitfalls

General information only (not legal advice). Confirm requirements with your local government, Building and Energy, and your building surveyor/certifier.

Quick links
Owner-builder approval (WA) Building permit (WA) Essential protections (WA)

Quick comparison

New build
  • Cleaner sequencing (slab → frame → lock-up → fit-off)
  • Approvals and compliance are usually “from scratch”
  • Fewer surprises behind existing finishes
  • Still requires strong documentation + inspections
Renovation / extension
  • Higher risk of rework (hidden defects, non-compliant legacy work)
  • Insurance complexity (existing home policy usually won’t cover build risks)
  • Staging constraints (weatherproofing, temporary services, access)
  • Often more variations (scope creep and “while we’re at it…”)
WA-specific note
Owner-builder approval in WA commonly comes up when the total value of work exceeds $20,000 — and it can apply to extensions/alterations as well as new builds. (Value is usually about the overall value of labour + materials, not just “what you paid cash for”.)

What changes for owner-builders in renovations?

Insurance & “existing structures”
The most common trap
  • Existing home policies usually exclude construction-related loss/damage
  • You may need “existing structures” cover (or a specific renovation setup)
  • Confirm insurer position in writing before starting
Compliance interfaces
Joining old + new
  • Structural tie-ins need proper engineering (as required)
  • Waterproofing and drainage details matter more than people expect
  • Certifier will often want “before/after” evidence for key elements
Variations are more common
Budget + timeline protection
  • Expect discoveries after demolition
  • Write down scope changes immediately
  • Keep photos, dates, and trade confirmations
Liveability / site constraints
If you’re living on site
  • Temporary weatherproofing and safe access become “critical path”
  • Trade sequencing is harder (kitchen/bathroom outages)
  • Neighbours are more affected (noise, access, dust)
Essential protections (WA) Questions to ask your insurer

Common pitfalls (WA)

Starting demo before approvals are clear
Even “minor” changes can trigger planning/building requirements (and rework). Confirm your pathway early with council and your building surveyor/certifier.
Assuming owner-builder approval is only for new homes
Extensions/alterations can still trigger owner-builder approval depending on total value and who is the “builder” on the permit.
Poor waterproofing evidence
Waterproofing is a classic “covered up too soon” problem. Photograph prep, membranes, terminations, and certificates as you go.
No simple record system
Renovations generate lots of “micro-decisions”. Keep a single folder for approvals, photos, certificates, variations, and invoices.
Record-keeping template Inspections (WA)

Next recommended reads

Owner-builder approval

When it’s needed (and why value surprises people).

Read
Building permit

Certified vs uncertified, and what documents matter.

Read
Essential protections

Contract works, public liability, and renovation traps.

Read
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