How thick does a Passive House timber wall need to be?

Total wall thickness for a Passive House timber frame wall is typically 350–500 mm (including all layers from internal finish to external cladding). The structural frame is usually 200–300 mm deep (filled with insulation), with an additional 60–100 mm of external insulation to eliminate thermal bridging at studs.

Total wall thickness for a Passive House timber frame wall is typically 350–500 mm (including all layers from internal finish to external cladding). The structural frame is usually 200–300 mm deep (filled with insulation), with an additional 60–100 mm of external insulation to eliminate thermal bridging at studs. A typical build-up achieving U = 0.12 W/m²K is approximately 420 mm total thickness.

Why this matters

This question relates to Passive House Timber Construction: Achieving U-Values Below 0.15, which covers the broader topic in detail. Understanding this specific aspect helps architects, builders, and timber dealers make informed specification decisions.

For full context and additional technical detail, see our comprehensive guide:

→ Passive House Timber Construction: Achieving U-Values Below 0.15

Related questions

• Can you build a Passive House with timber frame?
• What U-value is required for Passive House walls?
• What is the best insulation for a Passive House timber frame?

About this answer

This answer is part of the PuurModulair Knowledge Base — comprehensive timber specification guidance for architects, builders, and dealers across the UK, EU, and Scandinavia. All technical content is reviewed by qualified timber technologists before publication.