What happens if your block does not meet CDC standards?

Failing the complying development checklist is not the end of the project. It means the fast approval pathway is closed and you move to a development application, where council assesses your proposal on its merits rather than against a fixed list. Plenty of granny flats that miss the checklist by a small margin get approved this way.

You usually have 5 options. Here they are, and how to work out which one applies.

This matters more than it sounds, because the options depend entirely on which standard you missed.

The first 4 are facts about your land that no design can change. The rest are about the building, and a building can be changed.

Worth exhausting before anything else, because complying development stays the fastest and cheapest route.

The most common fixes:

• Drop the height below 3.8 m. Height above 3.8 m increases both side and rear setbacks, and the rear loading is 3 times the extra height. Coming down under 3.8 m can hand you back several metres of building envelope.
• Make the granny flat smaller. A 45 m² 2-bedroom fits where a 60 m² will not.
• Move it. A different position on the block can resolve a setback or a landscaping problem.
• Remove a structure. An old shed, a disused slab or a pool can be what is consuming your envelope.
• Change the roof form. Roof design affects overall height.

A good designer will run these before telling you the block does not work.

The standard path when the block itself is the problem.

A DA is a merit assessment. Council weighs your proposal against its own local planning controls and can approve things the fixed checklist cannot. A block that is 430 m² instead of 450 m², or has 11 m of frontage instead of 12 m, is exactly the kind of near miss that DAs exist for.

The trade-off is time, cost and certainty. You are asking rather than qualifying.

Often overlooked, and genuinely useful on tight blocks.

A secondary dwelling located within the principal dwelling has a different and simpler set of requirements. It needs to meet the Building Code, must not be on environmentally sensitive or heritage land, and can involve no external alterations beyond adding one entrance. It still cannot exceed 60 m².

If you have a large garage, an under-house area or a rarely used wing, this can deliver a self-contained dwelling without touching the yard, the setbacks or the landscaped area requirements at all.

Some failures are practical rather than legal.

• Sewer main under the build zone. A build-over application or a diversion. Both cost money and time, but both are done routinely.
• A tree. Removal may be possible with council consent, or the building can move outside the protection zone.
• An easement. Usually you cannot build over it, but you may be able to build around it.

These are cost and time problems, not permission problems.

If the envelope only fits 40 m², a well-designed 40 m² one bedroom is a real granny flat that someone can live in comfortably. It is worth more than a 60 m² design that never gets built.

Do not try to argue with a certifier. A certifier assessing a complying development application has no discretion. That is the entire design of the pathway. If your proposal misses a standard, the certifier cannot approve it regardless of how reasonable the variation seems. The place where discretion exists is council, through a DA.

Do not build first and seek approval later. Unapproved building work creates problems with insurance, with sale of the property, and with council enforcement, and it can be ordered removed.