Addition and existing house: differential settlement at the junction
A new foundation and an older house may not move the same way. Plan soil, support, joint, enclosure and services at the transition.
Decision triage
VERT / GREEN · JAUNE / YELLOW · ROUGE / RED
What the professional checks
The professional checks soil, old/new foundations, load transfer, movement accommodation, junction waterproofing and service connections.
Official sources
- SCHL — rénovation de maisons anciennes et fondations d’agrandissement
- SCHL — tassement et conditions de sol
Sources checked: 2026-08-24
Related path
Continue with the right tools
These links connect this page to the next useful checks and decisions without repeating the full content.
Plan a complete construction projectConnect feasibility, design, permits, concealed work, commissioning and closeout.Open →Check permit triggersPrepare the questions and documents to confirm with the local authority.Open →Check a contractorDocument licence, insurance, scope, payments, changes and warranties.Open →Update a construction costEscalate a historical cost using comparable index values.Open →Prepare pre-delivery reviewRecord documents, enclosure, systems, finishes and deficiencies before closeout.Open →
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Advanced diagnostics to cross-check
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Explore: Specialized systems to cross-check
Specialized systems to cross-check
This section completes gas, soil, water, fire, climate and structural interfaces.
Explore: Project risks and overlooked interfaces
Project risks and overlooked interfaces
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