Overview
EN ISO 7518:1999 (ISO 7518:1983) defines rules for the simplified representation of demolition and rebuilding on construction drawings. It standardizes symbols, markings and graphical conventions used on general arrangement drawings and assembly drawings-primarily plans, but also views and sections-to clearly show existing parts to be retained, parts to be removed, and new construction. The standard helps ensure consistent, unambiguous technical drawings for demolition and reconstruction projects.
Key topics
- Scope and purpose
- Rules for symbols and markings that indicate demolition, rebuilding and retained elements on construction drawings.
- Applies mainly to plans; similar conventions may be used for views and sections.
- Graphical conventions
- Use of contrasting line types and weights to differentiate existing, removed and new parts (e.g., thin lines, thick lines, thin lines with crosses).
- Hatching or shading to show areas of construction or removal, following ISO 4069 principles.
- Dimensions and textual information
- Guidance on how to present existing and new dimensions and text; removed elements may be struck through, and new information clearly distinguished.
- Recommendation to differentiate original versus new dimensions by numeral height or text style when helpful.
- Clarity and amplification
- Emphasis on clear contrast between retained, removed and new elements; drawings should be supplemented by text when needed.
- Recommended practice: provide both the original (existing) state annotated with planned changes and a separate drawing of the altered building.
- Structured representation
- Outlines, dimensions and descriptive information for building parts are organized in tabular form as part of the standard’s guidance.
Applications
- Architects, structural and civil engineers, CAD technicians, draftspeople and contractors use EN ISO 7518 when preparing:
- Demolition and reconstruction drawings for refurbishment, retrofit and partial rebuilding projects
- Permit and planning submissions where communication of proposed removal and new work must be unambiguous
- Shop and assembly drawings that show staged removal and replacement of components
- Useful for building owners, surveyors and authorities reviewing demolition scopes or change-of-use proposals.
Related standards
- ISO 128 - Technical drawings: general principles of presentation
- ISO 3098-1 - Technical drawings: lettering (commonly used characters)
- ISO 4069 - Representation of areas on sections and views (hatching/shading conventions)
- Adopted as CEN standard: EN ISO 7518
EN ISO 7518 supports clear, consistent demolition and rebuilding documentation-reducing misinterpretation, improving coordination on site, and streamlining regulatory review. Keywords: ISO 7518, EN ISO 7518, technical drawings, construction drawings, demolition representation, rebuilding symbols, hatching, CAD standards.
