Heating for a Canberra granny flat.
Canberra winters demand a heating system that actually performs at -7°C. Four genuine options, four very different running cost profiles. Here’s the honest framework.
Four heating systems compared.
| System | Install | Running cost (55m², winter) | Comfort |
|---|---|---|---|
| RC inverter AC (Daikin URURU) | $3,400–$5,200 | $280–$420 winter season | Fast response, slight air-flow |
| In-slab hydronic (Rinnai gas) | $11,200–$16,400 | $420–$680 winter season | Excellent — even, silent |
| In-slab hydronic (Daikin Altherma HP) | $14,800–$22,400 | $260–$400 winter season | Excellent — even, silent, low energy |
| Gas wall heater (Rinnai Energysaver) | $2,200–$3,400 | $540–$820 winter season | OK — localised heat, dry air |
| Wood-burning stove | $4,800–$7,200 | $400–$600 winter (wood) | Excellent ambient, requires work |
Honest recommendation by use case.
Standard tenanted granny flat.
Reverse-cycle inverter AC (Daikin URURU, Mitsubishi GE-series, Panasonic Aero). Hard to beat — $4K install, $300/yr to run, cools AND heats. Tenant just sets temperature and lives. Default for 80% of our ACT builds.
Premium build, owner-occupied or premium rental.
In-slab hydronic with heat pump (Daikin Altherma). $18K–$22K install but lowest running cost. Even radiant heat throughout, no air-blowing noise, no visible AC unit. Premium feel, premium rental market response.
Budget-driven build, occupant’s comfort secondary.
Gas wall heater. $2–$3K install but $600–$800 winter running cost. Stand-alone heater, no AC for summer. Acceptable for short-term rental property if budget is the priority.
Owner-occupied retreat, rural-flavour Inner South.
Wood-burning stove. Aesthetic appeal, real character, excellent radiant heat. BUT requires firewood handling, ash management, and annual chimney service. Most ACT residential applications go for the AC option instead.
Why in-slab hydronic costs 4x as much.
The hydronic system requires:
- In-slab PEX pipework (laid in the concrete pour)
- Heat source (gas boiler $4,200, or heat pump $8,800)
- Manifold + zone controls
- Thermostat + sensor system
- Insulation under slab (R1.0+)
- Commissioning + balancing
What you get for the premium: silent, even, radiant warmth from the floor. No visible equipment in the room. No dry-air complaints. No drafts. Maintains 21°C effortlessly even when outside is -5°C. Premium experience.
The summer cooling question.
Canberra summers do get hot — 30°C+ January afternoons. Your heating choice often determines cooling:
- RC inverter AC: Cooling is built in. Done.
- Hydronic + ceiling fans: Often sufficient if the build is well-shaded and well-insulated.
- Hydronic + separate split AC: Premium combo. Add another $2,800–$4,200.
- Gas wall heater: Need separate cooling. Plus another $2,500–$3,500.
- Wood stove: Need separate cooling. Plus another $2,500–$3,500.
Reverse-cycle inverter AC is the cheapest TOTAL solution when you factor in both winter AND summer.
Where we work.
We design heating for the actual climate.
Not retrofitted from a NSW template. Free heating-system consult included in every quote.