diff --git a/packages/core/src/validation/validate-build-json.test.ts b/packages/core/src/validation/validate-build-json.test.ts
index 64e3d0972e..e7d20ebb25 100644
--- a/packages/core/src/validation/validate-build-json.test.ts
+++ b/packages/core/src/validation/validate-build-json.test.ts
@@ -126,3 +126,48 @@ describe('validateBuildJson with registered plugin kinds', () => {
     expect(result.schemaIssues[0]?.nodeType).toBe('trees:tree')
   })
 })
+
+describe('scene materials', () => {
+  const minimalGraph = () => ({
+    nodes: {
+      building_1: { id: 'building_1', type: 'building', children: ['level_1'] },
+      level_1: { id: 'level_1', type: 'level', children: [] },
+    },
+    rootNodeIds: ['building_1'],
+  })
+
+  test('carries valid materials through to parsed', () => {
+    const result = validateBuildJson({
+      ...minimalGraph(),
+      materials: {
+        mat_a: {
+          id: 'mat_a',
+          name: 'Measured cabinet',
+          material: { properties: { color: '#595c5a' } },
+        },
+      },
+    })
+    expect(result.ok).toBe(true)
+    expect(result.parsed?.materials?.mat_a?.name).toBe('Measured cabinet')
+  })
+
+  test('skips invalid material entries with a warning, keeps the rest', () => {
+    const result = validateBuildJson({
+      ...minimalGraph(),
+      materials: {
+        mat_ok: { id: 'mat_ok', name: 'Fine', material: {} },
+        mat_bad: { name: 42 },
+      },
+    })
+    expect(result.ok).toBe(true)
+    expect(Object.keys(result.parsed?.materials ?? {})).toEqual(['mat_ok'])
+    expect(result.warnings.some((w) => w.code === 'invalid_materials')).toBe(true)
+  })
+
+  test('warns when materials is not an object', () => {
+    const result = validateBuildJson({ ...minimalGraph(), materials: 'nope' })
+    expect(result.ok).toBe(true)
+    expect(result.parsed?.materials).toBeUndefined()
+    expect(result.warnings.some((w) => w.code === 'invalid_materials')).toBe(true)
+  })
+})
diff --git a/packages/core/src/validation/validate-build-json.ts b/packages/core/src/validation/validate-build-json.ts
index 1257a43ef2..19615386c8 100644
--- a/packages/core/src/validation/validate-build-json.ts
+++ b/packages/core/src/validation/validate-build-json.ts
@@ -1,4 +1,5 @@
 import { nodeRegistry } from '../registry'
+import { SceneMaterial } from '../schema/scene-material'
 import { AnyNode, type AnyNodeType } from '../schema/types'
 import { healSceneNodes } from '../utils/heal-scene-graph'
 
@@ -24,6 +25,8 @@ export type ParsedBuildJson = {
   nodes: Record<string, unknown>
   rootNodeIds: string[]
   installedPlugins?: string[]
+  /** Scene materials referenced by node `slots` (`scene:<id>`). */
+  materials?: Record<string, SceneMaterial>
 }
 
 export type SchemaIssue = {
@@ -111,6 +114,7 @@ export function validateBuildJson(input: unknown): ValidateBuildJsonResult {
   const nodesRaw = input.nodes
   const rootNodeIdsRaw = input.rootNodeIds
   const installedPluginsRaw = input.installedPlugins
+  const materialsRaw = input.materials
 
   if (!isPlainObject(nodesRaw)) {
     errors.push({
@@ -160,6 +164,46 @@ export function validateBuildJson(input: unknown): ValidateBuildJsonResult {
     })
   }
 
+  // Scene materials ride along with the graph: nodes reference them by
+  // `scene:<id>` slot refs, so dropping the table here silently strips
+  // every custom finish from the imported scene. Invalid entries are
+  // skipped one by one — a bad material must not take the import down.
+  //
+  // DELIBERATE: `safeParse().data` NORMALIZES — defaults are injected
+  // and unknown keys dropped. That is the opposite of the API boundary
+  // (`apiGraphSchema` preserves unknown fields on purpose), and it is
+  // chosen here because import feeds the live scene store, which only
+  // understands schema-shaped materials; a hand-edited file with a
+  // half-formed material should land as something the renderer can
+  // draw, not round-trip garbage.
+  let materials: Record<string, SceneMaterial> | undefined
+  if (isPlainObject(materialsRaw)) {
+    let skipped = 0
+    const kept: Record<string, SceneMaterial> = {}
+    for (const [id, value] of Object.entries(materialsRaw)) {
+      const result = SceneMaterial.safeParse(value)
+      if (result.success) {
+        kept[id] = result.data
+      } else {
+        skipped += 1
+      }
+    }
+    if (Object.keys(kept).length > 0) materials = kept
+    if (skipped > 0) {
+      warnings.push({
+        severity: 'warning',
+        code: 'invalid_materials',
+        message: `Ignored ${skipped} invalid scene material${skipped === 1 ? '' : 's'}.`,
+      })
+    }
+  } else if (materialsRaw !== undefined) {
+    warnings.push({
+      severity: 'warning',
+      code: 'invalid_materials',
+      message: 'Ignored invalid "materials" — expected an object of id → material.',
+    })
+  }
+
   if (strippedChildRefs > 0 || droppedWallIds.length > 0) {
     warnings.push({
       severity: 'warning',
@@ -373,6 +417,7 @@ export function validateBuildJson(input: unknown): ValidateBuildJsonResult {
           nodes,
           rootNodeIds,
           ...(installedPlugins ? { installedPlugins } : {}),
+          ...(materials ? { materials } : {}),
         }
       : null,
     stats,
diff --git a/packages/editor/src/components/ui/sidebar/panels/settings-panel/index.tsx b/packages/editor/src/components/ui/sidebar/panels/settings-panel/index.tsx
index fecc75978c..4b466466fa 100644
--- a/packages/editor/src/components/ui/sidebar/panels/settings-panel/index.tsx
+++ b/packages/editor/src/components/ui/sidebar/panels/settings-panel/index.tsx
@@ -2,6 +2,7 @@ import {
   clearSceneHistory,
   emitter,
   useScene,
+  type ParsedBuildJson,
   validateBuildJson,
 } from '@pascal-app/core'
 import { useViewer } from '@pascal-app/viewer'
@@ -287,16 +288,16 @@ export function SettingsPanel({
     e.target.value = ''
   }
 
-  const handleConfirmImport = (parsed: {
-    nodes: Record<string, unknown>
-    rootNodeIds: string[]
-    installedPlugins?: string[]
-  }) => {
+  const handleConfirmImport = (parsed: ParsedBuildJson) => {
     const currentScene = useScene.getState()
     setScene(
       parsed.nodes as Parameters<typeof setScene>[0],
       parsed.rootNodeIds as Parameters<typeof setScene>[1],
       {
+        // Without this, every `scene:<id>` slot ref in the imported file
+        // pointed at a material that no longer existed — custom finishes
+        // silently reverted to defaults on import.
+        materials: parsed.materials,
         installedPlugins: parsed.installedPlugins ?? currentScene.installedPlugins,
         hasExplicitPluginInstallState:
           parsed.installedPlugins !== undefined || currentScene.hasExplicitPluginInstallState,