Heat Pump Installation for Existing Homes (Retrofit)

Retrofitting a heat pump into an existing home is different from new builds. You’re working with established layouts and existing materials, which brings up a lot of complications. Varcoe specializes in retrofits — we’ve had decades of experience integrating new heat pump systems into older homes without unnecessary disruption or surprises.

What You Get With Retrofit Installation

System Options for Retrofit

Wall-Mounted Splits (Most Common)

Single indoor unit on your chosen wall
Outdoor condenser on your property
Works in any home, any ceiling type
Installation: 3-4 hours typically
Cost: $2,500-$4,500 installed
Best for: Quick retrofit, affordable, minimal disruption

Ceiling Cassettes

If accessible ceiling cavities available
Requires careful ceiling work (gib, plaster, concrete)
Cleaner interior aesthetic
Installation: 4-5 hours
Cost: $3,000-$5,500
Best for: Modern interiors, open-plan spaces

Ducted Retrofit

More complex for existing homes
Ductwork runs through existing cavities
Requires careful planning and access
Installation: 7-14 days typically
Cost: $10,000-$20,000+ (premium retrofit)
Best for: Whole-home comfort, homes with cavity space

Multi-Split Systems

Most existing home retrofits use wall-mounted systems (practical, affordable, minimal disruption).

What the Retrofit Installation Process Looks Like

Assessment Phase

We visit and assess your home thoroughly. Check ceiling/roof structure for cavity access. Evaluate wall strength for indoor unit mounting. Identify outdoor condenser placement. Review electrical system capacity. Assess any heritage or structural concerns. Provide detailed quote.

Pre-Installation Preparation

You clear wall space where unit will mount. Remove furniture if ceiling work involved. Arrange parking for Varcoe vehicle. Secure any heritage approvals if needed. Ensure electrical access is clear.

Installation Day

Indoor unit mounts to your wall. One hole drilled through exterior wall. Outdoor condenser positions on your property. Licensed electrician handles power connections. Refrigerant lines run cleanly. Minimal disruption to your home. Installation typically 3-4 hours.

Testing & Handover

System tested thoroughly. You receive Electrical Certificate of Compliance. Full training on temperature controls, modes, and maintenance. All questions answered. Warranty documentation provided.

Total timeline

1-2 weeks for most retrofits

Assessment and quote: 2-3 days
Approval/scheduling: 3-7 days
Installation: 3-4 hours (wall units) or 5-7 days (ducted)

Why Choose Varcoe for Retrofit Installation

50+ years retrofitting heat pumps into existing homes
Heritage home specialists (heritage materials, council requirements)
Licensed technicians
12-month workmanship guarantee
Free onsite assessment with honest quote
Experience with all home ages and construction types

Retrofit vs. New Build

Factor	Retrofit	New Build
Planning	Work around existing systems	Plan from day one
Access	Limited, creative solutions	Full access during construction
Disruption	Minimal to moderate	Can coordinate with build
Cost	Standard to premium	Lower (coordinated)
Timeline	3-4 hours (wall units)	Ducted integrates during build
Complexity	Higher (existing materials)	Lower (purpose-designed)

What to Expect: Timeline & Costs

Item	Details
System type	Wall-mounted (most common), cassette, or multi-split
Cost range	$2,500-$8,000 for standard retrofits
Installation time	3-4 hours (wall) to 5-7 days (ducted)
Disruption	Minimal to moderate
Warranty	12 months on our work + 5-year manufacturer (on parts and labour)
Maintenance	Annual service, filter checks every 3 months
Lifespan	15+ years with proper maintenance

Special Offer: Warmer Kiwi Homes Funding

Eligible homeowners get up to 80% of retrofit costs covered (capped at $3,450 including GST) via the Warmer Kiwi Homes initiative. Any system type. We’re approved and handle paperwork.

Check your Warmer Kiwi Homes eligibility

FAQ: Retrofit Heat Pump Installation

My home is 40+ years old. Can I retrofit?

Yes. We retrofit into homes of all ages. Older homes sometimes have excellent roof access. We assess your specific home and recommend the best approach.

Will retrofit damage my ceilings/walls?

No. We drill neatly and work carefully with existing materials. One hole for refrigerant lines and power. Any marks are cosmetic and easily touched up.

What if my ceiling is plaster (heritage)?

We have specialist experience with plaster ceilings. If cassettes are needed, we work carefully around plaster. Wall-mounted units are often practical for heritage homes.

Can I retrofit in stages? (Start with one room, add later?)

Yes. Start with a wall-mounted unit in one room. Add additional systems later. Multi-split systems allow you to expand to the same outdoor unit.

How much more does retrofit cost than new build?

Wall units cost the same as new builds ($2,500-$4,500). Ducted retrofit costs more ($10,000-$20,000+) because ductwork requires extra planning in existing homes.

My electrician mentioned upgrading my electrical system. What does that mean?

Older homes sometimes need electrical panel assessment. Most heat pumps work fine with existing supply. If upgrades are needed, your electrician will specify exactly what’s required and cost.

Ready to Add Climate Control to Your Existing Home?

Retrofit installation is straightforward when you work with someone who understands existing home challenges. Varcoe has retrofitted thousands of Auckland homes — heritage villas, weatherboard homes, modern townhouses, apartments.

We assess carefully. We recommend practical solutions. We install cleanly. We stand behind every retrofit with a 12-month guarantee.

Get your free retrofit assessment with Varcoe. We’ll evaluate your home, discuss options, and provide a detailed quote.