Home Energy Decisions

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Insulation & air sealing

Practical steps to stop drafts, cut heating/cooling waste, and make every future upgrade work better—starting with air sealing, then insulation.

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What this topic covers

If your home has cold rooms, uneven temperatures, or stubborn winter bills, insulation and air sealing are usually the highest-leverage starting point.

The goal isn’t “more insulation everywhere.” It’s to stop air leaks first, then add insulation where it actually changes comfort and heating/cooling load.

Do this well and your next big-ticket decision (HVAC, water heater, solar) gets easier—because the house needs less energy in the first place.

Quick wins (highest ROI moves)

Air seal first (attic penetrations, top plates, hatch), then add insulation.
Fix obvious duct leaks if ducts run through an attic/crawlspace.
Treat comfort complaints as diagnostics (cold rooms often mean air leaks or airflow issues).
Measure before/after with utility bills (or a simple bill breakdown) instead of guesses.

A sensible sequence

1) Find the leaks that matter

Start with the attic: recessed lights, bath fan housings, plumbing stacks, chimney chases, and the attic hatch. In basements/crawlspaces, look for rim-joist leaks and big penetrations. If you can see daylight, you’re losing conditioned air.

2) Air seal (then insulate)

Air sealing is the multiplier. Insulation over air leaks underperforms and can hide moisture problems. Once the big leaks are sealed, add or top-up insulation where it’s accessible (often attic first).

3) Address moisture + ventilation

Sealing a house changes airflow. Make sure bath fans work, dryer vents are clean, and combustion appliances are safe. If you tighten the house a lot, plan for controlled ventilation.

4) Re-check comfort + airflow

After the envelope is improved, reassess cold/hot rooms. Sometimes the remaining issue is duct balance, supply/return placement, or an undersized pathway for air to move.

5) Right-size future HVAC

A better envelope lowers heating/cooling load. That can reduce equipment size and cost, and it improves heat pump performance. This is why insulation-first sequencing often saves money twice.

Tools to run the numbers

Use these to turn guidance into a personalized plan.

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Insulation & Air Sealing ROI

Estimate payback and savings using adjustable assumptions (not hype).

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Bill Breakdown

Separate heating/cooling from the rest of your bill to measure improvements.

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My Plan

Turn the steps into a now/next/later roadmap matched to your home.

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Recommended reading

Hand-picked guides that go deeper on the common decisions.

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Air sealing weekend checklist

A practical DIY checklist for the biggest leaks homeowners can fix quickly.

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Insulation before a heat pump

How envelope upgrades change equipment sizing and comfort outcomes.

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Attic insulation ROI

How to think about savings, payback, and the comfort benefits.

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Duct sealing payback (+ quote checklist)

When duct fixes are high ROI—and what to ask contractors.

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Cold / hot rooms: root causes

A diagnosis-first guide for uneven temperatures.

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FAQ

Should I air seal or insulate first?

Air seal first. Insulation slows heat flow, but air leaks can bypass insulation entirely. Seal the big leaks, then insulate for predictable comfort and savings.

How much attic insulation is “enough”?

It depends on climate and what you already have, but the bigger win is usually air sealing. After sealing, add insulation to a level that makes sense for your climate and access—attics are often the cheapest place to add R-value.

Do I need a blower door test?

It’s not required, but it’s extremely helpful if you’re doing deeper work or chasing stubborn comfort issues. A blower door plus infrared scan can reveal leaks you’d otherwise miss.

Want the fastest path to action?

If you want a now/next/later roadmap tailored to your home, start with the My Plan tool.

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