How much insulation a house needs in IECC climate zone 4 — attic, walls, and floor

A house needs the most insulation overhead: in climate zone 4 the IECC requires R-60 in the attic, R-30 in the walls, and R-19 in the floor. The thicker the layer, the higher the R-value.

A house cross-section showing where insulation goes and how much each part needs in IECC climate zone 4: the attic or ceiling needs R-60 (a thick blown-in layer), the exterior walls need R-30 (batt in the stud cavity), and the floor needs R-19 (batt between the joists). The attic layer is drawn thickest because it requires the highest R-value. Values are the 2021 IECC prescriptive minimums from Table R402.1.3. — Source: 2021 IECC Table R402.1.3

Use this diagram free on your site — grab the embed codeGet the code

What this diagram shows

A house cross-section showing where insulation goes and how much each part needs in IECC climate zone 4: the attic or ceiling needs R-60 (a thick blown-in layer), the exterior walls need R-30 (batt in the stud cavity), and the floor needs R-19 (batt between the joists). The attic layer is drawn thickest because it requires the highest R-value. Values are the 2021 IECC prescriptive minimums from Table R402.1.3.

Use this diagram — free

You're welcome to use this diagram on your own site, blog, handout, or lesson at no cost. The only condition is a visible credit link back to the source page. Copy the snippet below and paste it into your page — the credit is already included.

Embed code (HTML)

<figure style="margin:0;max-width:800px">
  <a href="https://remodelcalculators.com/construction-diagrams/iecc-insulation-assemblies" target="_blank" rel="noopener">
    <img src="https://remodelcalculators.com/api/figure-embed/iecc-insulation-assemblies" alt="A house cross-section showing where insulation goes and how much each part needs in IECC climate zone 4: the attic or ceiling needs R-60 (a thick blown-in layer), the exterior walls need R-30 (batt in the stud cavity), and the floor needs R-19 (batt between the joists). The attic layer is drawn thickest because it requires the highest R-value. Values are the 2021 IECC prescriptive minimums from Table R402.1.3." width="800" height="480" style="width:100%;height:auto;border:0" loading="lazy">
  </a>
  <figcaption style="font:14px/1.4 -apple-system,sans-serif;margin-top:6px;color:#555">
    Diagram: <a href="https://remodelcalculators.com/construction-diagrams/iecc-insulation-assemblies" target="_blank" rel="noopener">How much insulation a house needs in IECC climate zone 4 — attic, walls, and floor</a> — courtesy of <a href="https://remodelcalculators.com" target="_blank" rel="noopener">RemodelCalculators.com</a>
  </figcaption>
</figure>

Please keep the credit link intact and don't alter the diagram itself. Redistribution as part of a competing diagram library or template pack isn't permitted. Questions? Reach us via the site.

Was this diagram helpful?

Insulation Calculator

Free insulation calculator for fiberglass batts, blown-in cellulose, spray foam & rigid board. Bags by square footage, R-value by climate zone, code check.

Open calculator Jump to figure

Read the guide: Iecc Climate Zone 4