Taking on your own build as an owner-builder means you carry responsibilities a registered builder would normally hold — including making sure the right documentation reaches your building surveyor. Structural drawings, computations and certification are a core part of that package.
Here's what's involved on the engineering side, and where owner-builders most often get stuck.
What is an owner-builder?
In Victoria, an owner-builder is someone who takes on the role of builder for domestic building work on their own property. Above a set value of work, you need a Certificate of Consent from the state building regulator before you can obtain a building permit, and there are eligibility requirements — including completing a mandatory eLearning assessment and meeting restrictions on how often you can do it.
The regulator's own website is the authoritative source for eligibility, thresholds and the application process, and it's worth reading before you commit. Requirements do change.
What documentation does a building permit need?
Building surveyors typically expect a package that includes architectural drawings and a site plan, a soil report and site classification, structural drawings and computations with certification, energy efficiency documentation, stormwater and drainage details, title documents, and the owner-builder consent itself. Additional items apply on some sites — a bushfire assessment, for example, or septic and land capability documentation on unserviced land.
The exact list comes from your building surveyor. Ask for it early and in writing.
Where the structural engineer fits
Your structural engineer produces the parts of that package relating to the structure:
- Footing and slab design based on your soil report
- Framing, beams and lintels
- Structural computations supporting the design
- Certification of the structural design for the permit
Note that structural documentation is sometimes split into separate sets — foundation and building — depending on the project and the surveyor's preference.
Our residential structural engineering team prepares complete structural documentation for owner-builder projects across Melbourne.
Where owner-builders commonly get stuck
Three patterns come up repeatedly:
Documentation arriving out of order. Structural design needs the soil report first, and the soil report needs the design footprint. Getting these in the wrong sequence causes delays.
Assuming a standard detail will do. Kit or standard details often don't suit a specific site's soil classification, slope or wind exposure. Site-specific design is usually needed.
Discovering site constraints late. Easements, drainage requirements and boundary conditions are much cheaper to design around than to redesign for. Check them before the design is finalised.
Your responsibilities
Acting as owner-builder means the obligations that normally sit with a registered builder sit with you — compliance, safety, and coordinating the practitioners involved. Warranty and insurance obligations can also apply, particularly if you sell within a defined period after completion. These have real legal consequences, so get advice specific to your situation from the regulator or a suitably qualified professional rather than relying on general guidance.
A practical note: engaging good consultants doesn't reduce your responsibility, but it does mean the technical documentation is sound — which is where most compliance problems start.
Building as an owner-builder in Melbourne? Talk to a Melbourne structural engineer about your structural documentation.
Frequently asked questions
Do owner-builders need a structural engineer? Yes — structural drawings, computations and certification form part of the building permit documentation, regardless of who is acting as builder.
What documents does an owner-builder need for a building permit? Typically architectural drawings, soil report, structural drawings and computations with certification, energy documentation, stormwater details, title documents and the owner-builder consent. Your building surveyor confirms the full list.
Do I need a Certificate of Consent? Above a set value of domestic building work, yes — it's issued by the state building regulator and is required before you can obtain a building permit. Check current thresholds and eligibility with the regulator.
Can I use standard or kit structural details? Often not without checking. Standard details may not suit your site's soil classification, slope or wind exposure, so site-specific design is usually required.
What order should I do things in? Broadly: design concept, land and soil information, then structural and civil design, then the permit application. Your building surveyor can confirm the sequence for your project.
