Planning Consent, Building Consent and What to Bring an Engineer

Most delays on a new build are not caused by the work. They are caused by the order it was done in.

The commonest version goes like this. An owner engages an engineer early, because that feels organised. The footing design is prepared off the drawings that exist at the time. Planning consent then comes back with a condition, the floor level moves 300mm, a wall shifts to meet a setback, and the footing design has to be done again. Nobody did anything wrong. The sequence was wrong.

This is the sequence that works in South Australia, and what you need in your hand at each step.

Three Words That Are Not Interchangeable

Under the Planning, Development and Infrastructure Act 2016, what you are ultimately issued is a Development Approval. It is not one assessment. It is the point at which every consent your project needs has been granted.

• Planning consent assesses the proposal against the Planning and Design Code: what you are building, where it sits, setbacks, height, overshadowing, site coverage, stormwater, access. It is about whether the development belongs on that land.
• Building consent assesses the same proposal against the Building Rules and the National Construction Code: whether the thing will stand up, drain, resist fire and be safe to occupy. Structural documentation is assessed here, by council or by a private certifier.
• Development Approval is issued once the required consents are in place. Work cannot start before it, whatever any individual consent says.

Land division consent is a fourth where a block is being divided. Some minor work is “accepted development” needing building consent only, and some is exempt entirely. The Code is applied by zone, so what your block needs is specific to the block. Check it on the SA Planning Portal at plan.sa.gov.au or with your council before you plan around an assumption.

What You Need Before You Come to Us

There are two answers, and which one applies depends on which half of the work you are asking for.

For civil work, bring the architectural planning drawings

Site and drainage plans, stormwater design and the civil documentation that supports a planning application are prepared from architectural planning drawings. Site plan, levels, footprint, floor plans and elevations. That is all that exists at that stage of a project and it is all we need, because what we are documenting is where the building sits on the land and where the water goes.

This work is usually part of what gets lodged for planning consent, which is why it comes first. Waiting for working drawings before starting the civil side is the other way people lose a month.

For footings and structure, wait for the working drawings

Footing design and structural design are prepared from working drawings, the documented set an architect or building designer produces after planning consent is granted. Those are the drawings that carry final wall positions, openings, roof framing, floor levels and the details a footing layout actually responds to.

It is not that a footing cannot be designed off planning drawings. It is that it will be designed twice. A planning consent condition, a setback adjustment or a level change moves the things a footing plan is dimensioned to, and the second design is not free.

The Sequence

1. 1

   Concept and architectural planning drawings

   You bring: a brief, the block, any survey you hold.

   You get: site plan, floor plans, elevations. Enough to lodge, not enough to build from.

2. 2

   Civil design, from those drawings

   You bring us: the planning drawings and the survey.

   We issue: site and drainage plan and the civil documentation the planning application needs.

3. 3

   Planning consent lodged and assessed

   Assessed against: the Planning and Design Code, by the relevant authority.

   Outcome: planning consent, often with conditions that change something.

4. 4

   Working drawings prepared

   Why here: the design is now fixed, so what is drawn is what gets built.

   This is the gate. Structural design before this point is design that may have to be repeated.

5. 5

   Soil test and site classification

   You bring us: nothing, we arrange it, or your own report if you have one.

   We get: the site classification under AS 2870, which the footing responds to.

6. 6

   Footing and structural design

   You bring us: the working drawings, the soil report, and anything you know about fill or removed trees.

   We issue: footing layout, structural drawings and certification.

7. 7

   Building consent lodged and assessed

   Assessed against: the Building Rules and the National Construction Code, by council or a private certifier.

   Outcome: building consent.

8. 8

   Development Approval, then build

   Then: construction, with trench and steel inspections at the points that matter and a watch kept for the issues that tend to surface during building.

   Note: work cannot start before Development Approval is issued.

What to Send With the Working Drawings

A footing design is a response to the ground and to the building, so the more of both we have, the fewer assumptions end up in the design. Send whatever you hold of:

• the working drawings, including floor levels and any retaining or level changes
• a soil report and site classification, if one has been done
• a survey, particularly on a sloping block or where levels are tight
• anything you know about fill: how deep, when it went in, whether it was compacted and tested
• trees on or near the block, including ones that have been removed and when
• the frame type, roof material and any unusual spans the builder has in mind

None of that is a hurdle. Every item on it is something that would otherwise be assumed conservatively, and a conservative assumption is a footing you pay to build.

Where This Goes Wrong

Engaging structural too early. The design is prepared, planning consent changes something, and it is prepared again.

Engaging civil too late. The site and drainage plan is often part of the planning application, so leaving it until after planning consent has the whole thing waiting on a document that could have been done at the start.

Changing the drawings after the design is issued. Moving a wall, adding a storey or changing floor level after the footing plan is out is a variation, not an amendment. It is much cheaper to tell us it is coming than to tell us afterwards.

Assuming approval is a formality. It usually is. The cases where it is not are the ones where somebody planned the build around an assumption about the Code that was true for a different zone.

This article is general information about the approval process in South Australia. It is not advice for a specific site, and it does not replace confirming requirements with your council, a registered building certifier, or the SA Planning Portal. Requirements are applied by zone and change over time.