Skip to content
Capsule & prefab homes · Companies, buying and building

← Construction & installation

CasasCápsula library · 2026-10-12

Modular thermal envelopes how to substantiate performance before selling

Published 2026-10-12 · Updated 2026-10-31 · Leer en español
Facade insulation during retrofit.
Facade insulation during retrofit. Marek Ślusarczyk (Tupungato) Photo portfolio · CC BY 3.0

A 120 mm wall does not define a home’s energy performance. A repeatable envelope requires documented materials, junctions and operating conditions, plus confirmation that the finished unit matches the assessed design.

From insulation datasheet to building

Insulation conductivity is an input. Wall transmittance also depends on layers and heat-flow paths. Metal framing, window subframes and fixings can change assembly performance. Our editorial recommendation is to request an identifiable calculation for each solution and control its variants.

DB HE is Spain’s energy-saving reference. Its application requires the project scope and relevant climate and use assumptions. Calculated annual heating demand is not whole-building electricity consumption: heating, cooling, hot water and auxiliaries use different assessment boundaries.

Junctions must be buildable

We suggest recording how insulation continuity, airtightness, external water and service penetrations are managed. Every window or panel substitution should trigger review; preserving nominal catalogue thickness is insufficient.

Communicating Passive House

The Passive House Institute publishes building certification criteria and procedures. Manufacturers should distinguish a certified component, a solution designed using that methodology and a building that has actually obtained certification. Commercial documents should identify precisely which claim is supported.

A useful designer handover

This English version retains the Spanish regulatory scope of the original.

Explore our guides and articles

Do you work in industrialised housing?

Do you manufacture, install or prepare technical documents? Tell us which problem you need to solve, or share a documented project that could help other professionals.

Contact CasasCápsula

Sources and scope

Sources reviewed 11 October 2026. Handover and control lists are CasasCápsula editorial recommendations; they do not replace project calculations, tests or documents.

Related reading

Have a question about this topic? Contact us (Spanish form) →
← Back to all guides