Standards & Design | Solar & Heat Pumps

Solar Panels & Heat Pumps for Multiplex Buildings in BC

Electrification is the path forward for BC buildings. Heat pumps are effectively required for Step Code 3+. Solar PV is not yet mandated but solar-ready construction is increasingly required. Here is what each technology costs and delivers for a typical multiplex.

Heat Pumps: The Foundation of Green Multiplex

Heat pumps extract heat from outdoor air (even in cold weather) and deliver it indoors. In cooling mode, they reverse the process. A single system replaces both furnace and air conditioner while using 40-60% less energy than gas heating.

Air-Source Heat Pump (ASHP)

COP 2.5-4.0

Cost

$8,000-$15,000 per unit

Best For

Standard multiplex heating/cooling. The default choice for BC.

Note

Most common for multiplex. Provides both heating and cooling. BC's mild climate makes ASHPs extremely efficient year-round.

Mini-Split (Ductless)

COP 3.0-4.5

Cost

$4,000-$8,000 per unit

Best For

Individual unit control, supplemental heating, or buildings without duct systems.

Note

Often used in combination with a central system. Individual per-unit control reduces disputes in rental buildings.

Ground-Source Heat Pump (GSHP)

COP 3.5-5.0

Cost

$25,000-$50,000 per building

Best For

Larger projects (8+ units) where ground loop cost is spread across more units.

Note

Highest efficiency but highest upfront cost. Requires drilling or horizontal ground loop. Rarely cost-effective for 4-6 unit multiplex.

Heat Pump Comparison

Air-Source: Cost-effectiveness

5/5

Best value for most multiplex projects

Air-Source: Efficiency

4/5

COP 2.5-4.0 — excellent in BC climate

Mini-Split: Flexibility

5/5

Per-unit control, easy retrofit

Mini-Split: Whole-building heating

3/5

Better as supplement than sole source

Ground-Source: Efficiency

5/5

Highest COP, lowest operating cost

Ground-Source: Upfront cost

2/5

Rarely pencils for <8 units

Solar PV: The Economics in BC

Why Solar Can Work

• BC Hydro net metering credits excess generation against consumption
• Federal Greener Homes grant covers part of installation cost
• Panel costs have dropped 70% in the past decade
• Roof-mounted panels on a multiplex have better economics than single-family (more units share the cost)

Why Solar is Still Optional

• BC electricity is already cheap (~$0.10/kWh) — payback is 12-18 years
• Multiplex roofs are often complex (dormers, slopes) reducing usable area
• Shared metering complicates ownership and billing for strata
• Solar-ready construction ($1,500-$3,000) is a better bet than full install today

Solar-Ready: The Smart Minimum

Many municipalities now require solar-ready construction for new buildings. This is cheap insurance: $1,500-$3,000 during construction vs $5,000-$10,000 to retrofit later.

Electrical Rough-In

Conduit from electrical panel to roof. Reserved breaker space for future solar inverter connection.

Structural Blocking

Roof framing designed to support future panel weight (3-5 lbs/sq ft). Blocking installed at attachment points.

Documentation

Roof area analysis showing usable solar area. Orientation and shading assessment. Future installation plan.

Ventilation: HRV vs ERV for Tight Buildings

As airtightness improves at Step 3 and above, mechanical ventilation with heat recovery is no longer optional — it is required. The choice between HRV and ERV affects both energy performance and occupant comfort.

Exhaust-only (bath fans + passive inlets)

None (0%)

Cost Per Unit

$500-$1,200

Annual Energy Savings

Baseline (no recovery)

IAQ Benefit

Basic code compliance. Relies on negative pressure and passive air inlets.

Step Code Minimum

Step 1-2 only

Cheapest upfront but throws away 100% of the heat in exhausted air. Not permitted at Step 3+ due to energy penalty.

HRV (Heat Recovery Ventilator)

70-80% sensible heat recovery

Cost Per Unit

$2,500-$4,500

Annual Energy Savings

$400-$700 per unit vs exhaust-only

IAQ Benefit

Balanced supply and exhaust with filtration. MERV 13 filters standard on most units.

Step Code Minimum

Step 3+ (required)

The workhorse for BC multiplex. Lifebuoy, Fantech, and Zehnder units commonly specified. One unit per dwelling is typical; shared systems require careful balancing.

ERV (Energy Recovery Ventilator)

75-85% total energy recovery (sensible + latent)

Cost Per Unit

$3,000-$5,500

Annual Energy Savings

$500-$850 per unit vs exhaust-only

IAQ Benefit

Recovers both heat and moisture, reducing winter dryness. Better comfort in heating-dominant climates.

Step Code Minimum

Step 3+ (recommended for Step 4-5)

Preferred over HRV in BC's climate because it recovers moisture in winter. Slightly higher cost but better occupant comfort and lower humidification loads.

Passive House certified MVHR

90-95% sensible heat recovery

Cost Per Unit

$5,000-$8,000

Annual Energy Savings

$700-$1,100 per unit vs exhaust-only

IAQ Benefit

Highest filtration grade. Virtually eliminates cold drafts. Required for PHI certification.

Step Code Minimum

Step 5 / Passive House

Zehnder ComfoAir or Paul Focus series are the most common Passive House certified units in BC. The 90%+ recovery rate is what makes Step 5 airtightness practical without supplemental heating.

Solar PV Economics by System Size

Solar payback in BC is longer than Alberta or Ontario due to cheap hydro electricity. But panel costs continue to drop, and net metering makes the math gradually better. Here is what each system size delivers on a typical multiplex roof.

3 kW (8-10 panels)

Payback: 22-30 years

Install Cost

$9,000-$12,000

Annual Generation

3,000-3,600 kWh

Annual Savings

$350-$450

Minimal system. Covers common-area electrical loads only. Difficult to justify on financial returns alone at current BC Hydro rates ($0.10-$0.15/kWh).

5 kW (14-16 panels)

Payback: 20-26 years

Install Cost

$14,000-$18,000

Annual Generation

5,000-6,000 kWh

Annual Savings

$550-$750

Suitable for 4-plex common loads + partial unit offset. Net metering with BC Hydro credits excess generation at retail rate, improving economics.

8 kW (22-26 panels)

Payback: 19-24 years

Install Cost

$21,000-$27,000

Annual Generation

8,000-9,600 kWh

Annual Savings

$900-$1,200

Good match for a 6-plex roof. Covers 25-35% of total building electrical load. The sweet spot where BC Hydro net metering keeps credits positive year-round.

10 kW (28-32 panels)

Payback: 19-25 years

Install Cost

$26,000-$34,000

Annual Generation

10,000-12,000 kWh

Annual Savings

$1,100-$1,500

Maximum practical size for a typical multiplex roof. Combined with Step 5 envelope, can achieve net-zero energy on an annual basis. Required for Passive House net-zero certification path.

✓Air-source heat pumps are the default choice — effective, affordable, and increasingly required by Step Code.
✓Solar PV is optional but solar-ready is increasingly mandatory — spend $1,500-$3,000 now to keep the option open.
✓Battery storage is not cost-effective for BC multiplex today — BC's cheap hydro electricity and lack of time-of-use pricing make the payback too long.

Best For

✓ All new multiplex construction (heat pumps are effectively required at Step 3+)
✓ Purpose-built rental where lower operating costs are a competitive advantage
✓ Projects pursuing CMHC green incentives or net-zero certification

Usually Fails When

✕ The electrical panel upgrade required for all-electric exceeds available service capacity (check with BC Hydro early)
✕ The site is heavily shaded and solar PV would produce negligible output
✕ Ground-source is specified on a small project where the drilling cost exceeds the efficiency benefit

What To Verify Before Spending Money

→ BC Hydro service capacity at the lot (can it support all-electric heating for the planned unit count?)
→ CleanBC and BC Hydro rebate eligibility for the specific heat pump system you plan to install
→ Solar-ready requirements in your municipality's building bylaw

Frequently Asked Questions

Are heat pumps required for new multiplex in BC? +

Not explicitly mandated in all municipalities, but effectively required by Step Code 3 and above. Gas heating makes it very difficult to meet Step 3+ energy targets. Many municipalities have also adopted zero-carbon step code provisions that penalize fossil fuel heating.

How much does solar PV cost for a multiplex? +

A typical 5kW residential system costs $15,000-$25,000 before rebates. For multiplex, you need to consider shared vs individual metering and net metering agreements with BC Hydro. Solar-ready rough-in (conduit, panel space, structural blocking) costs $1,500-$3,000 and is increasingly required by code.

Is battery storage worth it for a multiplex? +

Not yet for most projects. Battery storage (e.g., Tesla Powerwall at $10,000-$15,000 per unit) is cost-prohibitive relative to BC's cheap hydro electricity. The exception is projects targeting net-zero certification or those in areas with time-of-use pricing, which BC does not currently have.

What is the solar-ready requirement? +

Many municipalities now require new buildings to be 'solar-ready' — meaning conduit from the electrical panel to the roof, reserved breaker space, and structural blocking for future panel mounting. This costs $1,500-$3,000 during construction vs $5,000-$10,000 for retrofit. It is insurance against future solar economics improving.