What is the best insulation for a Passive House timber frame?

The most common insulation combinations are: (1) Mineral wool between studs + wood fibre board externally — good performance, vapour-open, cost-effective. (2) Cellulose (blown) between studs + wood fibre externally — excellent sustainability credentials, good acoustic performance.

The most common insulation combinations are: (1) Mineral wool between studs + wood fibre board externally — good performance, vapour-open, cost-effective. (2) Cellulose (blown) between studs + wood fibre externally — excellent sustainability credentials, good acoustic performance. (3) Wood fibre throughout (between studs + external) — fully natural, vapour-open, excellent summer comfort. All achieve similar U-values; the choice depends on sustainability priorities, budget, and summer overheating risk.

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

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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.