Overview
ISO 7518:1983 specifies a simple, standardized way to show demolition and rebuilding on technical construction drawings. It defines rules for symbols, line styles, hatching and text markings used in general arrangement and assembly drawings - primarily plans, but applicable to views and sections as well. The standard helps distinguish existing elements to keep, elements to remove, and new construction so that drawings are unambiguous for design, permitting and execution.
Key topics
- Scope and purpose: Rules for simplified representation of demolition and reconstruction on construction drawings; tables list outlines, dimensions and text information for building parts.
- Graphic conventions:
- Existing parts to keep - shown with fine lines (no special convention required).
- Existing parts to be demolished - indicated by fine lines with crossing marks.
- New work - indicated by stronger/heavier lines to provide clear contrast.
- Dimensions and text:
- Existing dimensions and information to be retained - no specific convention required.
- Dimensions/text for parts to be demolished - may be shown with a line or cross through the dimension/text.
- New dimensions/information - shown distinctly (e.g., stronger line weight or text differentiation); differentiation of old/new dimensions can be emphasized by different text heights or styles.
- Hatching and surface representation:
- Use clear hatches or pochage to represent existing and new parts; where applicable, apply hatching conventions in line with ISO 4069.
- Presentation guidance:
- For clarity, include both an annotated drawing of the existing building (showing planned changes) and a new drawing of the transformed building.
- Reference drawing and text standards: ISO 128 (general presentation), ISO 4069 (surfaces on sections and views), ISO 3098-1 (drawing lettering).
Applications
ISO 7518 is practical for:
- Architects and architectural drafters preparing renovation, restoration or adaptive-reuse drawings
- Structural and building services engineers documenting alterations
- CAD technicians producing permit, tender and demolition-phase documents
- Contractors and site managers reviewing demolition scope from drawings
- Authorities reviewing plans for permits and safety compliance
The standard improves communication between design, statutory and construction stakeholders by making demolition/rebuilding intent visually explicit.
Related standards
- ISO 128 - Technical drawings: presentation principles
- ISO 4069 - Building drawings: representation of surfaces on sections and views
- ISO 3098-1 - Technical drawing lettering (general characters)
Keywords: ISO 7518, demolition representation, construction drawings, building drawings symbols, simplified representation, ISO 4069, ISO 128, renovation drawings.