The R-Value Math (Actual Numbers)
BC requires R-12 minimum added insulation for attic projects. That sounds low, but here's why it matters:
- Your attic probably has R-4 to R-8 (if you're in a 1980s house)
- Adding R-12 gets you to R-16-R-20 total
- A decent attic should be R-30-R-40 to compete with modern builds
But here's the installer shortcut: they meet code minimum (R-12 added), you sign off, and you leave money on the table. Actual energy savings start at R-30.
The rebate math: R-12 added costs ~$1,500-$2,000 installed with $1,200-$1,500 rebate. R-30 added costs ~$3,500-$4,500 installed with $2,000-$3,000 rebate.
You pay more, save more. Over 20 years, the R-30 install saves $6,000-$8,000 extra in heating costs versus the R-12 install.
The Three Types of Attic Insulation
Blown-In Fiberglass
Cost: $500-$800/1,000 sq ft. Speed: Fast (crew does it in 6 hours). Drawback: Settles over time (you lose 10-15% R-value after 10 years). Can be fire hazard if too close to recessed lights.
Use this if you're meeting minimum code only.
Blown-In Cellulose
Cost: $600-$1,000/1,000 sq ft. Pros: Treated to resist fire, denser than fiberglass (resists settling), better acoustic insulation. Con: Slightly higher labor cost (equipment heavier).
Better choice if you're going past R-20. Most BC homeowners should choose cellulose. It's better than fiberglass, cheaper than spray foam, and installers know how to do it right.
Spray Foam
Cost: $1,500-$2,500/1,000 sq ft. Pros: Doesn't settle, seals air leaks as it expands, reduces moisture problems. Con: Over-spray voids rebates, under-spray wastes money.
Use only if you're also doing energy-recovery ventilation.
The Installation Mistakes That Happen Every Day
Blocking Soffit Vents
Soffit vents let air flow from outside through the attic to ridge vents. Proper attic ventilation removes moisture and summer heat.
A lazy crew insulates right over soffit vents, blocking airflow. Your attic stays damp. Mold grows. Your insulation absorbs moisture and stops working.
Ask: "Did you install baffles to keep soffit vents open?" If they look confused, they didn't do it.
Not Sealing Air Leaks First
Insulation slows heat transfer. Air leaks move warm air straight out of your house.
Before they blow anything, they should seal: gaps around pipes and wires (caulk or foam), top plate of exterior walls (foam sealant), attic hatch (weatherstripping), electrical penetrations (foam + caulk).
If your installer skips this and just blows insulation, they're charging you for 30% less benefit.
Too Much Insulation Around Recessed Lights
Old recessed lights (pre-2010) generate heat and need clearance. Blow insulation around them, you melt the trim ring, it catches fire.
New LED recessed lights (IC-rated) don't generate heat and can be buried.
Ask: "Are all my recessed lights IC-rated?" If no, the installer must leave air space around them.
The Moisture Question
BC is wet. Your attic can develop moisture problems, especially if ventilation is poor.
Signs something's wrong: black mold on roof sheathing, wet insulation (looks darker than surrounding), moisture on nails (they "sweat").
If this exists before you insulate, you're trapping moisture. Fix the ventilation first.
Ask: "What's the current moisture level in the attic?" "Is ventilation adequate?" If they say "looks fine," they haven't checked properly.
The Rebate Reality
BC's CleanBC program offers $1,200-$1,500 rebate for attic insulation. Income-qualified households get more.
Typical project: 1,500 sq ft attic, adding R-12, costs $2,000-$2,500 with $1,500 rebate (or $2,500 if income-qualified).
That's a good deal. But installers sometimes quote high, knowing you'll see the rebate number and say yes without comparing.
Get 2-3 quotes. Compare: material (fiberglass vs cellulose), R-value added, pre-insulation work (sealing, inspection), warranty.
The Combo Play (Attic + Heat Pump)
If you're doing both upgrades: Insulate the attic first (lowers heating demand), then size the heat pump smaller (saves $1,500-$2,000). Rebates stack on both. Order matters. Heat pump sizing depends on your home's insulation level.
What to Ask Before You Sign
- "Will you conduct a pre-work inspection and moisture check?"
- "What are you sealing before you blow?"
- "Are all my recessed lights IC-rated?"
- "What R-value are you targeting? Why?"
- "How long will this keep working?" (Good installers warranty 10 years)
- "What happens if moisture shows up after you're done?"
The One Number That Matters
Average energy savings: $400-$600/year (varies by current insulation and climate zone).
Payback: 3-5 years.
After that, it's just money in your pocket.