What to Know Before Considering House Underpinning

Note when cracks, movement, sticking doors, uneven floors or other changes appeared, where they are and whether they are changing. Take dated photographs from a safe location and retain previous inspection or repair records. These signs can have different causes and do not prove that underpinning is needed.

Engage a suitably qualified structural engineer and, where needed, a geotechnical professional to investigate the actual building and ground. Ask what evidence supports the diagnosis, which alternatives were considered, what monitoring is needed and what conditions would require further review. Do not excavate, inject, jack or modify foundations without an engineered design and proper authorisation.

Foundation work may affect services, boundaries, neighbouring structures, drainage and planning or building approvals. Confirm requirements with the local council and building authority, and have a qualified professional coordinate the design and suitable contractor. NSW homeowners can start with Building Commission NSW building and renovation resources; other jurisdictions have their own regulators.

Before authorising work, request the engineer’s report and design, contractor licence details, contract scope, sequence, monitoring, insurance, variation process and completion documents. Seek independent legal or building advice about a significant project or disputed recommendation.

Cleaning after construction is a separate task once the site is released. A cleaner cannot assess settlement, verify structural repair, certify foundations or remove hazardous materials. Confirm the builder’s handover and surface readiness before requesting ordinary cleaning.