1. Convert an internal room — Guest room, formal dining, or under-stair nook. 1 – 4 weeks. $2k – $18k.
2. Enclose a verandah or alfresco — Adds a bright, quiet office without touching the main house. 4 – 8 weeks. $18k – $48k.
3. Prefab / kit garden studio — Delivered and installed. 8 – 14 weeks. $28k – $75k depending on insulation, power, split system.
4. Custom-built garden studio — Fully insulated, plumbed if needed, matched to the house. 3 – 6 months. $65k – $140k.
5. Extension with a dedicated wing — Adds an office + guest bed + bathroom. 8 – 14 months. $180k – $380k.

• A door you can close (video calls, kids, deliveries).
• Genuine acoustic separation — plasterboard alone is not enough.
• Reliable wired ethernet, not just Wi-Fi.
• South-facing or blade-shaded window — no direct sun on the desk.
• Split system for winter and summer, on a separate zone.
• Enough power points for a monitor setup, printer, phone charger.
• Bookshelf or joinery that hides cables.
• A view of something living — a plant, garden, or tree.

Internal reconfigure: $2k – $18k depending on joinery, lighting, acoustic treatment.

Enclose a verandah as a home office: $18k – $48k. Requires council approval in most Adelaide zones.

Prefab garden studio (15 – 18 sqm, insulated, split system): $28k – $52k delivered. Add $8k – $15k for power connection.

Custom-built garden studio (18 – 30 sqm, matched to house): $65k – $140k depending on cladding, glazing, bathroom.

Rear extension with home office + ensuite: $180k – $380k.

Most Adelaide councils allow a small studio (under 20 sqm, no plumbing) as an ancillary structure — but always confirm setbacks and boundary distances.

If the studio has a bathroom or kitchenette, it may be treated as a habitable second dwelling, which changes the approval process and can affect land tax status.

Also worth knowing:

• Home office running costs can be partially tax-deductible — talk to your accountant.
• Selling later: a proper home office adds noticeable resale value in the current market.