Toxic Substances
Building regulations covering toxic substances released by building materials. The single substantive requirement (D1) prohibits insulating materials that release formaldehyde gas in concentrations harmful to occupants. Rarely engaged on modern domestic extensions because mainstream insulation products are already compliant, but remains the statutory hook if a non-standard insulating material is proposed.
Also known as
Pages where Part D comes up
Part D is in the graph but no published guide currently links to it. As leaves get authored or expanded the cross-link sweep will pick them up here automatically.
Want the full picture?
The buildwiz build guides walk through a UK extension in sequence and link to Part D (and every other Approved Document) at the exact stage it bites. That is usually a more productive way to use this material than reading the document cover to cover.