The three real options (in order of speed)
- Reconfigure what you have — Convert a study, close in a verandah, or rezone rooms. 4 – 10 weeks. $8k – $40k.
- Extend or add a second storey — Buys you a nursery + a guest room + storage. 6 – 14 months. $180k – $720k depending on scope.
- Move to a larger home — Fastest path to real space but hardest with a newborn on the way. ~$74k – $88k in transaction costs before the new mortgage.
Anything that finishes after week 34 of pregnancy is functionally “after the baby” — plan the decision around that date, not the due date.
The timing math no one shows you
Rough Adelaide timelines from “we should do something” to “we can live in it”:
- Small internal reconfigure: 6 – 12 weeks total
- Kitchen + open-plan reshape: 4 – 6 months
- Rear extension (25 – 35 sqm): 10 – 14 months
- Second storey addition: 14 – 20 months
- Sell + buy established: 3 – 5 months if you are ready
- Sell + build new: 16 – 26 months from decision to move-in
If you are past 20 weeks and want a nursery ready, only options 1 and 5 are honest.
What actually solves “we need more space”
Most couples think they need square metres. Usually they need storage and separation. Score your current house honestly:
- Is there a room you can convert without touching structure?
- Is the problem cupboards, not walls?
- Do you have a second living space so a napping baby does not stop the household?
- Can you carve a laundry / mud-room from the garage or verandah?
A $28k joinery-and-storage refit often fixes what people mistake for “we need a bigger house”.
Real Adelaide numbers (2026)
Renovate for a baby:
- Nursery joinery + repaint: $6,000 – $14,000
- Study-to-bedroom conversion: $18,000 – $35,000
- Rear extension (add 1 bed + 1 bath): $220,000 – $360,000
- Second storey (2 bed + bath): $420,000 – $720,000
Move up one bedroom: transaction cost ~$74k – $88k plus the price gap between homes. Established 4-bed vs 3-bed within the same suburb usually adds $180k – $340k in South Australia.
If you are going to build or extend — do this first
- Get 3 builders quoting the same scope. Different scopes are unreadable.
- Insist on a fixed-price contract with a clear variation policy — variations after week 30 of your pregnancy are torture.
- Ask for a Gantt-style schedule, not a “handover in Q3” line.
- Plan where you will actually live during the build. Family, short-lease, or stage the build in two phases.