Lb overview

1. Layout Builder Overview

When to Use

When you need visual layout control for entity displays — sections, multiple columns, block-based composition, per-entity or per-bundle layouts.

Decision

If you need...	Use...	Why
Per-bundle layout with sections and blocks	Layout Builder with defaults	Stored in view display config, exportable, visual editor, no content duplication
Per-entity custom layouts	Layout Builder with overrides enabled	Allows individual entities to override default layout, stored in entity field
Global site structure (header, footer, sidebars)	Block Layout (core Block system)	Site-wide regions, not entity-specific
Structured field-based content composition	Paragraphs module	Content modeling, reusable field collections, revision control at field level
Landing pages with full visual control	Layout Builder + Page Manager	Combines layout control with routing/context

Pattern

Core concept: Layout Builder extends entity view displays with sections. Each section has a layout plugin (defines regions) and components (blocks placed in regions).

# core.entity_view_display.node.article.default.yml
third_party_settings:
  layout_builder:
    enabled: true
    allow_custom: false  # true enables per-entity overrides
    sections:
      - layout_id: layout_twocol_section
        layout_settings:
          label: ''
        components:
          - uuid: abc-123-uuid
            region: first
            configuration:
              id: 'field_block:node:article:title'
            weight: 0

Reference: /core/modules/layout_builder/config/schema/layout_builder.schema.yml for complete config structure.

Common Mistakes

Using LB for site structure → Use Block Layout for headers/footers (site-wide regions). LB is for entity display, not site architecture
Enabling overrides by default → Start with defaults only. Overrides create maintenance burden — can't update existing content when defaults change
Mixing layout concerns → Use Block Layout for site structure, LB for entity layouts, Paragraphs for content modeling. Each solves different problems
Ignoring config export → LB config is just YAML in entity_view_display. Export it like any config, use recipes for reusable patterns
Forgetting about inline block orphans → Non-reusable blocks persist in DB when removed from layout. Run cron regularly or use cleanup modules