Prince Edward Island · climate zone 6 · prices and rebates checked October 8, 2026

Insulation and upgrade payback calculator for Charlottetown

Charlottetown has 4,404 heating degree-days a year (climate zone 6), and NRCan recommends about R-60 in an attic here. For a typical detached house of about 1,600 sq ft (149 m²) built between 1966 and 1980 with a oil furnace, mid-efficiency, topping up the attic from R-20 to R-60 saves about $200 a year at $1.47/L and costs about $1,200–$1,960; the smallest open rebate that applies (efficiencyPEI Home Insulation Rebates) is $1,120. In an electrically heated house the same attic saves about $230 a year.

Heating degree-days

4,404

NBC climate zone 6

NRCan attic target

R-60

code minimum for new homes R-49.2

Electricity, one more kWh

$0.205/kWh

used for every saving

Open rebate programs

1

efficiencyPEI Home Insulation Rebates

Upgrade payback calculator for Charlottetown

Pre-filled for a typical 1966–1980 house in Charlottetown with Charlottetown's climate, prices and open rebates. The insulation levels are typical assumptions for the era, not measurements: change anything you know about your house. Nothing you enter leaves your browser.

Your house
Year built
Type
Size (heated floors above the basement)
sq ft
Heating and bills
$

Used for every saving (fixed charges left out).

$

Only used to turn a monthly bill into energy.

Calibrate to your bills (optional)

Based on a typical house

$1,830saved a year with 6 upgrades

About 1,250 L a year less for your oil furnace, mid-efficiency: 37.3 GJ of the 93.7 GJ of heat the house needs (40%).

Installed cost
$13,550–$21,460 + your quotes
Rebates counted
$2,270
Simple payback
12–20 years for the 4 upgrades with a cost
Saving over 20 years
$36,670

Enter your quote for wall insulation and basement wall insulation to add them to the cost and payback. The 4 upgrades with a cost save about $975 a year together.

Measures overlap, so the total (40% of your heating need) is less than the sum of each one alone (48%).

Add your annual use or a monthly bill to calibrate these numbers to your house. Most rebates need an EnerGuide evaluation before and after the work; their conditions are listed further down this page.

Attic insulation
R-
R-

NRCan recommends R-60 for climate zone 6; we cap the default at R-60. The building code minimum for a new house here is R-49.2.

sq ft
$
Or cost per sq ft (low – high)
$ – $

HomeStars (updated 21/08/2026): "installation costs range from $1.50 to $2.45 per square foot"; Canadian attic jobs average $1,500–$3,000 including materials and installation.

$200/yr · 4.0 GJ (4.3% of heating) · cost $1,200–$1,960 · $1,120 rebate · payback under 1 to 4.3 years

Wall insulation
How
RSI

R-12

sq ft
$

We couldn't verify a 2025–2026 Canadian price for wall insulation, so this starts blank. NRCan: on an exterior retrofit the insulation is only about 15–20% of the cost.

$445/yr · 9.1 GJ (9.7% of heating) · cost enter your quote · $1,580 rebate · payback enter a cost

Basement wall insulation
RSI

R-4

RSI

R-20

sq ft
$

$710/yr · 14.4 GJ (15.3% of heating) · cost enter your quote · $2,970 rebate · payback enter a cost

New windows
windows
$
Or cost per window (low – high)
$ – $

HomeStars (updated 21/08/2026): $800–$1,000 for a double-hung and $900–$1,200 for a casement window, installed; bay and bow windows $2,500–$4,000.

$415/yr · 8.4 GJ (9.0% of heating) · cost $12,000–$18,000 · $1,000 rebate · payback 27–41 years

Air sealing
%
ACH50

Leave the cut blank for our default: 20%, or 15% if your house tests under 4 ACH50. The blower-door number is on your EnerGuide report.

Cost (low – high)
$ – $

HomeStars (updated 21/08/2026): air sealing and ventilation "could add $350 to $1,500" to an attic insulation job.

$175/yr · 3.5 GJ (3.8% of heating) · cost $350–$1,500 · $150 rebate · payback 1.2–7.8 years

Thermostat setback
°C
hours a day
$

NRCan suggests 17 °C when you're asleep or away and 20 °C when you're home, and not going below 17 °C. $0 if you already have a programmable thermostat; we couldn't verify a 2025–2026 price for a new one.

$275/yr · 5.6 GJ (6.0% of heating) · cost $0 · no rebate counted · payback right away

Each upgrade on its own
UpgradeSaved a yearCost and rebatePayback20 years
Attic insulationR-20 → R-60 over 800 sq ft $200135 L a year $1,200–$1,960rebate $1,120 under 1 to 4.3 years $3,950
Wall insulationR-10 exterior insulation: RSI 2.1 → 3.9 over 1,580 sq ft $445305 L a year your quoterebate $1,580 enter a cost $8,950
Basement wall insulationRSI 0.7 → 3.5 over 890 sq ft of wall $710485 L a year your quoterebate $2,970 enter a cost $14,150
New windows15 windows: U 2.86 → 1.22 $415285 L a year $12,000–$18,000rebate $1,000 27–41 years $8,290
Air sealingA 20% cut in air leakage (NRCan: about 25% of heat loss) $175120 L a year $350–$1,500rebate $150 1.2–7.8 years $3,460
Thermostat setback3.0 °C lower for 8 hours a day $275190 L a year $0 right away $5,530

Savings use the price of one more unit of energy, not your average price. Each upgrade is shown on its own against your house as it is now; the total above accounts for overlap. Payback = (cost − rebate) ÷ yearly saving; the 20-year figure has no price increases or discounting.

Charlottetown at a glance: standard upgrades for a 1966–1980 house

Detached, about 1,600 sq ft over a full basement, two storeys, with the era's typical insulation (attic R-20, walls RSI 2.1, uninsulated basement walls, double-glazed windows). Savings use the price of one more unit of energy; costs are installed ranges where we could verify one.

Oil-heated (mid-efficiency furnace)
UpgradeSaved a yearCost and rebatePayback20 years
Attic insulationR-20 → R-60 over 800 sq ft $2004.0 GJ · 4.3% $1,200–$1,960rebate $1,120 under 1 to 4.3 years $3,950
Wall insulationR-10 exterior insulation: RSI 2.1 → 3.9 over 1,580 sq ft $4459.1 GJ · 9.7% get a quoterebate $1,580 enter a cost $8,950
Basement wall insulationRSI 0.7 → 3.5 over 890 sq ft of wall $71014.4 GJ · 15.3% get a quoterebate $2,970 enter a cost $14,150
New windows15 windows: U 2.86 → 1.22 $4158.4 GJ · 9.0% $12,000–$18,000rebate $1,000 27–41 years $8,290
Air sealingA 20% cut in air leakage (NRCan: about 25% of heat loss) $1753.5 GJ · 3.8% $350–$1,500rebate $150 1.2–7.8 years $3,460
Thermostat setback3.0 °C lower for 8 hours a day $2755.6 GJ · 6.0% $0 right away $5,530
Electrically heated (baseboards)
UpgradeSaved a yearCost and rebatePayback20 years
Attic insulationR-20 → R-60 over 800 sq ft $2304.0 GJ · 4.3% $1,200–$1,960rebate $1,120 under 1 to 3.7 years $4,570
Wall insulationR-10 exterior insulation: RSI 2.1 → 3.9 over 1,580 sq ft $5209.1 GJ · 9.7% get a quoterebate $1,580 enter a cost $10,360
Basement wall insulationRSI 0.7 → 3.5 over 890 sq ft of wall $82014.4 GJ · 15.3% get a quoterebate $2,970 enter a cost $16,380
New windows15 windows: U 2.86 → 1.22 $4808.4 GJ · 9.0% $12,000–$18,000rebate $1,000 23–35 years $9,590
Air sealingA 20% cut in air leakage (NRCan: about 25% of heat loss) $2003.5 GJ · 3.8% $350–$1,500rebate $150 under 1 to 6.7 years $4,000
Thermostat setback3.0 °C lower for 8 hours a day $3205.6 GJ · 6.0% $0 right away $6,410

The house needs about 93.7 GJ of heat a year here. Walls in this era already hold about RSI 2.1, so dense-packing gains nothing and the table shows R-10 of exterior insulation instead. Wall and basement prices start blank because we couldn't verify a 2025–2026 Canadian cost; the 20-year column shows what each upgrade is worth to compare with a quote.

Rebates for these upgrades in Prince Edward Island

Insulation, window/door and air sealing rebates continue through efficiencyPEI after a $99 assessment. Heat pump, heat pump water heater and other equipment rebates ended April 15, 2026, and the free heat pump program is closed.

Attic insulation

efficiencyPEI Home Insulation Rebates Open
Attic insulation: $3.50 per SQ per R-value increase (regular); $5.50 per SQ per R-value increase (low-income). Minimum: total R50 for flat ceilings, R28 for sloped ceilings.
Conditions: Book the subsidized home energy assessment ($99 + HST) with one of five listed providers first; get approval before work ("Upgrades done before approval will not be refunded"). Homeowners and landlords of residential properties. SQ = 100 square feet. Rates "as of June 2, 2025"; page dated September 2, 2026.
Deadline: Not stated.
Program details · official page ↗ · checked October 8, 2026

Wall insulation

efficiencyPEI Home Insulation Rebates Open
Above-grade walls (new interior/exterior finish): $50 per SQ per R-value increase (R6 minimum increase). Above-grade walls (blown-in insulation): $10 per SQ per R-value increase (R10 minimum increase). Low-income: $80 / $16.
Conditions: Book the subsidized home energy assessment ($99 + HST) with one of five listed providers first; get approval before work ("Upgrades done before approval will not be refunded"). Homeowners and landlords of residential properties. SQ = 100 square feet. Rates "as of June 2, 2025"; page dated September 2, 2026.
Deadline: Not stated.
Program details · official page ↗ · checked October 8, 2026

Basement wall insulation

efficiencyPEI Home Insulation Rebates Open
Below-grade: $21 per SQ per R-value increase (R12 increase for walls, R20 for headers); low-income $34. Exposed floors and headers: $21 per SQ per R-value increase (total R20).
Conditions: Book the subsidized home energy assessment ($99 + HST) with one of five listed providers first; get approval before work ("Upgrades done before approval will not be refunded"). Homeowners and landlords of residential properties. SQ = 100 square feet. Rates "as of June 2, 2025"; page dated September 2, 2026.
Deadline: Not stated.
Program details · official page ↗ · checked October 8, 2026

Air sealing

efficiencyPEI Home Insulation Rebates Open
Air sealing (improvement over initial ACH @ 50 Pa): 10% $150; 20% $375; 30% $575 (regular); low-income $250 / $650 / $1,000.
Conditions: Book the subsidized home energy assessment ($99 + HST) with one of five listed providers first; get approval before work ("Upgrades done before approval will not be refunded"). Homeowners and landlords of residential properties. SQ = 100 square feet. Rates "as of June 2, 2025"; page dated September 2, 2026.
Deadline: Not stated.
Program details · official page ↗ · checked October 8, 2026

Windows and doors

efficiencyPEI Home Insulation Rebates Open
Windows, doors, skylights (ENERGY STAR v5, 2020 onward): $125 per opening, max $1,000 per property (low-income $245 per opening, max $2,000).
Conditions: Book the subsidized home energy assessment ($99 + HST) with one of five listed providers first; get approval before work ("Upgrades done before approval will not be refunded"). Homeowners and landlords of residential properties. SQ = 100 square feet. Rates "as of June 2, 2025"; page dated September 2, 2026.
Deadline: Not stated.
Program details · official page ↗ · checked October 8, 2026

Financing

PEI Energy Efficiency Loan (Finance PEI)
official page ↗

Common questions in Charlottetown

Does attic insulation pay for itself in Charlottetown?

For a typical detached house of about 1,600 sq ft (149 m²) built between 1966 and 1980, going from R-20 to R-60 saves about $200 a year with a mid-efficiency oil furnace and $230 with electric baseboards, counted at the price of one more unit of energy. At HomeStars' $1.50–$2.45 per sq ft (about $1,200–$1,960) and a $1,120 rebate, simple payback is under 1 to 4.3 years (under 1 to 3.7 years for an electrically heated house). Attics with less than R-20 save more.

What insulation rebates are open in Charlottetown?

As of October 8, 2026: Attic insulation: efficiencyPEI Home Insulation Rebates (Attic insulation: $3.50 per SQ per R-value increase (regular); $5.50 per SQ per R-value increase (low-income)) Wall insulation: efficiencyPEI Home Insulation Rebates (Above-grade walls (new interior/exterior finish): $50 per SQ per R-value increase (R6 minimum increase)) Basement wall insulation: efficiencyPEI Home Insulation Rebates (Below-grade: $21 per SQ per R-value increase (R12 increase for walls, R20 for headers); low-income $34). Conditions apply (most need an EnerGuide evaluation before the work); the calculator counts the smallest amount for each and lets you switch it off.

How much insulation should an attic have in Charlottetown?

NRCan's Keeping the Heat In recommends about R-60 (RSI 10.6) for an attic in climate zone 6, which covers Charlottetown at 4,404 degree-days. The National Building Code minimum for a new house here is R-49.2 without a heat recovery ventilator. Our calculator caps its default target at R-60.

Are new windows worth it for energy savings in Charlottetown?

Rarely on energy alone. Replacing 15 double-glazed windows with ENERGY STAR models saves about $415 a year in a oil-heated house and $480 with electric heat, against $12,000–$18,000 at HomeStars' $800–$1,200 a window: payback 27–41 years. Replace windows when they fail or for comfort; air sealing and attic insulation pay back much faster.

How much do air sealing and a thermostat setback save in Charlottetown?

Cutting air leakage by 20% saves about $175 a year in a typical oil-heated house here (NRCan: about a quarter of heat loss is air leakage), and turning the thermostat down 3 °C for 8 hours a night saves about $275 a year (NRCan: about 2% per degree over eight hours). Heat pumps should be set back no more than 2 °C.

How we calculate this

1. Heat saved by insulation and windows

heat saved (GJ/yr) = area × (1/RSI before − 1/RSI after) × 4,404 degree-days × 86,400 s ÷ 10⁹ × F

F is a conservative factor: 0.75 above grade (the sun, people and appliances supply some heat, and no installation is perfect) and 0.4 for basement walls (most of the wall is below grade, where the ground stays far warmer than winter air). Windows use U-values instead of 1/RSI.

2. Typical starting points

  • Attic: R-12 before 1966, R-20 (1966–80), R-28 (1981–95), R-40 (1996–2010), R-50 (2011+). Target: NRCan's retrofit recommendation for climate zone 6, capped at R-60.
  • Walls: RSI 0.7 (empty, before 1946), 1.4 (1946–65), 2.1 (1966–95), 3.0 (1996–2010), 3.4 (2011+). Dense-packing a 2×4 cavity gives about RSI 2.1 (cellulose is RSI 0.63 per 25.4 mm, NRCan Table 3-1); R-10 of exterior insulation adds RSI 1.76.
  • Basement walls: RSI 0.7 before 1981 (bare concrete plus the soil against it), 2.1 for 1981–2010, 3.5 since; target RSI 3.5 (R-20).
  • Windows: 12% of floor area (1.2 m² each), single with storm before 1966, double clear 1966–95, double low-e after.

These starting values are AuditYourHome planning assumptions for a typical house of each era, not survey results: we could not verify a Canadian table of insulation levels by year built. Change them to match your house; an EnerGuide evaluation measures them.

3. Air sealing

Without a blower-door number we use NRCan's statement that typically about 25% of heat loss is air leakage: saving = 25% × reduction × heating need × 0.75. With your EnerGuide result (ACH50), everyday leakage is ACH50 ÷ 20, near the conservative end of the 10–25 range used in the field, and:

heat saved = drop in natural air changes × house volume × 1.21 kJ/m³·°C × degree-days × 24 ÷ 10⁶ × 0.75

We assume a 20% reduction (15% if the house is already under 4 ACH50); rebate programs pay for measured cuts of 10%, 20% and 30%.

4. Thermostat setbacks

NRCan: “A drop of 1°C (2°F) over an eight-hour period can save about 2 percent on your heating energy consumption.” Saving = 2% × degrees × hours ÷ 8. Heat pumps are limited to a 2 °C setback, NRCan's advice, because deep setbacks can bring on backup heat.

5. Caps, overlap and your bills

No single measure may save more than 35% of the heating need, and all of them together no more than 60%. Measures overlap (a better attic leaves less heat for new windows to save), so the combined saving is 1 − (1 − a)(1 − b)…, always less than the simple sum. If you enter bills, every saving is scaled by how your use compares with a typical house (between 0.5× and 1.6×).

6. Dollars, rebates and payback

payback (years) = (installed cost − rebate) ÷ yearly saving at the price of one more unit of energy

Rebates use each program's lowest published amount per unit (per home, per window, per sq ft or per sq ft × R-value added), only for programs open today and only where your heating fuel qualifies; you can switch each one off. The 20-year saving is the yearly saving × 20, with no price inflation or discounting. Where we could not verify a 2025–2026 installed cost (walls, basements, exterior insulation), the cost starts blank: enter your quote.

More for Charlottetown

Heating and hot water costs in CharlottetownWhat heating, hot water and air conditioning cost at your local prices, and what each heating system would cost instead.Home health check in CharlottetownRadon results, winter humidity and window condensation, smoke and CO alarm rules, well water and mould.Appliance running costs in CharlottetownWhat your fridge, dryer, freezer and other appliances cost to run at your local electricity price, and what a newer model saves.
Build your upgrade plan → All home services in Charlottetown Home energy audits in CharlottetownAttic insulation inspections in CharlottetownBlower door tests in CharlottetownThermal imaging in Charlottetown Prince Edward Island rebates and programs

Sources

Prices and programs checked October 8, 2026. Climate: NRCan HOT2000 (Charlottetown) for heating and ECCC 1981–2010 normals (Charlottetown A) for cooling and temperatures.

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