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Reviewed 25.10.2026England focus

Jasmine Gokmen
In forceStructure & Site

Approved Document D: Toxic substances

Insulating materials and harmful fumes

Limits the use of insulating materials that could release toxic fumes, particularly urea-formaldehyde foam used in cavity walls.

Also known as: AD D, Approved Document D

Jurisdiction
England
Document type
Statutory guidance
Edition
2010 edition
Source updated
2 December 2010
Applies from
—
Topic
Structure & Site

Key requirements

  • Restricts certain insulating materials in cavity walls and roofs.
  • Focuses on urea-formaldehyde foam and the risk of toxic fumes.
  • Requires consideration of accidental contact and fire conditions.
  • Read alongside product standards and the manufacturer's instructions.

Performance at a glance

Main material
Urea-formaldehyde foam
Focus
Toxic fumes and cavity insulation

Applies to

Building work involving insulating materials in England.

Official source

GOV.UK — Approved Document D

Open official source

Related records

Part C · Site preparation and resistance to contaminants and moisturePart 7 · Materials and workmanship

Reviewed 25 October 2026. This summary is an editorial reference, not legal advice. Check the current official text and confirm the approach with building control before relying on it. Browse all 35 records.