Quick answer
What homeowners need to know
Plan heating after improving the envelope and understanding room use, heat loss, zoning, ventilation and available electrical capacity.
Coordinate unit positions, pipe or duct routes, condensate and controls before finishes close.
Key takeaways
- List how each room is used before choosing any heater.
- Unit position affects comfort as much as capacity.
- Electrical capacity can limit what is possible.
- Insulation, glazing, airtightness, ventilation, moisture and heating work as a connected system.
Comfort, moisture & efficiency
Building a home renovation heating plan
List how each room is used before choosing any heater. A living area used every evening, a bedroom heated only at night and a home office used through the day have different needs. Writing this down helps a designer suggest zones and controls that suit the household, rather than one large unit that heats empty rooms or leaves the far end of the house cold.
Unit position affects comfort as much as capacity. A heat pump blowing straight at a sofa, or placed where furniture blocks its airflow, can feel uncomfortable or underperform. Check outdoor unit locations for noise near bedrooms and neighbours, condensate drainage and service access. Ducted systems need ceiling or underfloor space, so confirm duct routes before framing and linings are finished.
Electrical capacity can limit what is possible. Adding heat pumps, an induction cooktop and an electric vehicle charger in one renovation may exceed what the existing supply and switchboard can handle. Ask a registered electrician to assess the load early. New circuits need a certificate of compliance from the electrician, and switchboard upgrades are easier to coordinate before new finishes go in.
Scope before solutions
Decisions to make before committing
Settle these points before an idea becomes an order, contract or construction instruction.
Coordinate unit positions, pipe or duct routes, condensate and controls before finishes close.
existing envelope and moisture condition
access to walls, ceilings and subfloor areas
interaction between insulation, glazing, ventilation and heating
Practical sequence
A step-by-step planning process
- 01
Define the exact outcome you need and how success will be checked.
- 02
Assess moisture sources, insulation continuity, draughts, glazing, ventilation and heating together.
- 03
Prioritise repairs and passive improvements before sizing new mechanical systems.
- 04
Model or compare options using whole-of-life comfort, energy and maintenance outcomes.
- 05
Commission controls and give occupants clear operating and maintenance information.
Cost and time
How to build a more reliable budget and programme
A fixed price or completion date needs a measured scope and a site visit. Use suitably qualified professionals for energy modelling, electrical work, moisture diagnosis and any alteration that requires consent or specialist design.
Use the calculator, then request a site-specific assessment.
Risk control
Common mistakes to avoid
- Oversizing equipment does not compensate for draughts, poor insulation or uneven distribution.
- adding insulation without managing moisture and ventilation
- selecting products independently of the whole-house performance strategy
Accuracy and compliance
Use current official information
Primary sources used for this guide
- Insulate your home to improve energy efficiencyEECA
- Design or renovate a home for energy efficiencyEECA
- Check if you need consentsBuilding Performance (MBIE)
Common questions
Frequently asked questions
What size heat pump do I need after a renovation?
The right size depends on the room's heat loss after the renovation, not before it. Better insulation, glazing and draught-proofing can change the answer. Ask the installer to size the unit for the upgraded room, including ceiling height, glazing area and how open it is to other spaces, and to explain the method they used.
Is ducted heating better than wall heat pumps for a renovated home?
Neither is better in every case. Ducted systems can heat several rooms through discreet outlets but need ceiling or floor space and careful design. Wall-mounted units are simpler to add room by room. Compare how many rooms you need to heat, where space allows ducts and how you want to control each zone before deciding.
When should heating be decided in a renovation project?
Decide heating during design, before the electrical layout and framing are fixed. That lets pipe, duct and cable routes, condensate drains and outdoor unit positions be planned into the build. Leaving it until the end often means surface-mounted pipework, compromised unit locations or extra work to open up finished linings.