Renovation and Extension Inspections, Engineer-Led from Start to Warranty
For homeowners renovating or extending, builders, and owner-builders. Independent oversight at the point where most defects occur — the interface between your existing structure and new work.
The Old/New Interface Is Where Renovations Go Wrong
Renovations and extensions carry a structural and waterproofing risk that new builds do not — the connection between your existing structure and the new work. Footings tying into old foundations, waterproofing membranes meeting existing wet areas, structural frames connecting to walls that were never designed for the new load.
Most renovation oversight, where it exists at all, is provided by the builder's own site supervisor. BINM provides independent engineer-led inspection at the stages that matter most, plus a documented baseline before works begin and a structured review eighteen months after completion.
Independent oversight, from pre-works survey to 18-month warranty review.
Renovation and Extension Inspection / Advisory (Engineer-Led)
From Before the First Wall Comes Down to 18 Months After Handover
One service, structured around the lifecycle of your renovation — from before the first wall comes down to eighteen months after handover. Select individual stages or a full-stage package depending on your scope and budget.
Pre-Works — Before Construction Begins
Establishing a baseline and resolving risk before the first wall comes down.
Existing Condition (Dilapidation) Survey
A documented baseline of your existing property's condition before works begin — the same protection used for adjoining properties, applied to your own home. Protects you if a dispute arises about pre-existing versus new damage.
Design Documentation Review
Architectural and structural drawing review before construction starts, to identify clashes, omissions, or risks at the design stage — when they are cheapest to fix.
RFI / Building Surveyor Response Support
Engineering support to respond to requests for information from your building surveyor or certifier during the approval process.
Construction Stages — Independent Inspection at Every Critical Point
Seven checkpoints, with particular focus on the interface between new and existing structure.
Footing and Excavation Pre-Pour
Inspection before concrete is poured — the point at which footing and reinforcement issues are easiest to identify and impossible to fix afterward.
Post-Pour Slab Check
Confirms the slab was poured to specification, with a baseline level survey for future movement monitoring.
Structural Frame Inspection (Interface-Focused)
Specific attention to how the new structural frame connects to the existing building — the single most common source of renovation defects.
Pre-Plaster Inspection
The last opportunity to inspect framing, services, and waterproofing before walls are closed up.
Waterproofing Checkpoint
Critical at the old/new interface, where new wet areas meet existing structure. Waterproofing failures here are expensive and difficult to trace once finishes are installed.
Fix and Lock-Up Inspection
Final structural and compliance check before fixing trades complete their work.
Pre-Handover / Practical Completion Inspection
A full inspection of the renovated works before you accept handover, with a finished-floor baseline recorded for future reference.
Monitoring and Warranty
Baseline records now, peace of mind through your statutory warranty period.
Slab Baseline Level Survey (Post-Pour)
Establishes a reference point for any future movement monitoring.
Finished-Floor Baseline (PCI)
A second reference point recorded at handover, to compare against any future movement.
18-Month Warranty Movement and Defects Review
Most building defects and movement become apparent within the first eighteen months. BINM returns at this milestone to assess your renovation against the original baseline, while your statutory warranty period is still active.
If Something Goes Wrong, Your Data Is Already Escalation-Ready
Engineering-Level Report
If a defect or movement issue is identified at any stage, your inspection data is already sufficient to support a formal engineering report — no separate inspection required.
VCAT-Compliant Expert Report
If a dispute with your builder or contractor arises, the same data supports a dispute-ready expert report prepared by a Chartered Engineer.
Rectification Scope, Cost & PM
If rectification is required, BINM can provide the scope of works, cost estimates, and project management through to a verified resolution.
Renovating near a boundary or party wall? If your renovation involves excavation near a boundary, retaining wall work, or shared party walls, your neighbouring property may also need protection. See Adjoining Works Protection for dilapidation surveys, construction monitoring, and crack monitoring of neighbouring properties during your works.
View Adjoining Works ProtectionInspect. Report. Protect.
Three steps from booking to a documented, warranty-protected renovation.
Inspect
Book online or call 1800 796 776. Tell us about your renovation scope, timeline, and which stages you need covered. A Chartered Engineer is matched to your job with same-week availability.
Report
Inspection at each agreed stage, with all data, photos, measurements, and observations captured to support engineering escalation if required.
Protect
Receive your stage reports and your 18-month warranty review. If an issue is identified at any point, upgrade to an engineering or VCAT-ready report — no second site visit required.
Renovation and Extension Inspection Pricing
Pricing depends on the scope of works, number of stages, and property size. All pricing confirmed before booking.
Frequently Asked Questions
Everything you need to know about renovation and extension inspections.
You can select individual stages or a full-stage package from footing to practical completion. The stages with the highest defect risk — structural frame at the interface, pre-plaster, and waterproofing — are the ones we most commonly recommend if budget requires prioritising.
A dilapidation survey documents the condition of your existing structure before renovation works begin. If a dispute later arises about whether damage was pre-existing or caused during construction, this baseline record protects you.
The connection between new structural work and your existing building is the most common point of failure in renovations. Footings, frames, and load paths designed for new construction must tie into structure that was never designed to carry that load — and this is where engineering oversight matters most.
Most defects and structural movement become visible within eighteen months of completion. We return to assess your renovation against the baseline recorded at handover, while your statutory warranty period is still active, so any issues found can still be addressed by your builder.
You will likely need Adjoining Works Protection for your neighbour's property in addition to inspection of your own renovation. This includes a dilapidation survey of the adjoining property and construction monitoring during your works.
Yes. Because every stage inspection is engineer-led, the data collected can be escalated to a formal engineering report or a VCAT-compliant expert report without a separate inspection.