feat(properties): roll-up toggle on expenses/assets, new Maintenance + Todos tabs

Phase 4 — wires the descendant readers from Phase 2 into the UI.

- Expenses tab: ?descendants=1 query param toggles between
  "this property" and "include sub-properties". Affects the chart
  series, the 12-month summary, the recent-expense list, and the
  totals-by-kind chips.
- Assets tab: same toggle, expanded list across the property tree.
- New Maintenance tab on every property: schedules + recent events
  for assets at this property (or descendants), with overdue/active
  status badges. Scheduling itself stays at the asset level.
- New Todos tab: lists checklist instances scoped to this property
  (now possible thanks to the 'property' value added to
  checklist_scope in Phase 2). Open vs completed split.

Toggle only renders when childCount > 0 so leaf properties don't see
chrome they can't use. URL bookmarks without ?descendants stay on
the strict per-property view, preserving existing behavior.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

drizzle/0016_property_parent_id.sql

@@ -0,0 +1,3 @@
+ALTER TABLE "properties" ADD COLUMN "parent_id" uuid;--> statement-breakpoint
+ALTER TABLE "properties" ADD CONSTRAINT "properties_parent_id_properties_id_fk" FOREIGN KEY ("parent_id") REFERENCES "public"."properties"("id") ON DELETE restrict ON UPDATE no action;--> statement-breakpoint
+CREATE INDEX "properties_by_parent" ON "properties" USING btree ("company_id","parent_id");

drizzle/0017_property_parent_check.sql

@@ -0,0 +1,7 @@
+-- A property cannot be its own parent. Deeper cycle prevention (e.g.
+-- A→B→A) is enforced in the service layer because Postgres can't express
+-- recursive CHECK constraints; the assertNoCycle helper in
+-- src/lib/server/services/properties.ts walks ancestors before save.
+ALTER TABLE "properties"
+  ADD CONSTRAINT "properties_parent_not_self"
+  CHECK (parent_id IS NULL OR parent_id <> id);

drizzle/0018_checklist_scope_property.sql

@@ -0,0 +1 @@
+ALTER TYPE "public"."checklist_scope" ADD VALUE 'property';

drizzle/meta/_journal.json

@@ -113,6 +113,27 @@
       "when": 1776932900000,
       "tag": "0015_expenses_updated_at_trigger",
       "breakpoints": true
+    },
+    {
+      "idx": 16,
+      "version": "7",
+      "when": 1777268853483,
+      "tag": "0016_property_parent_id",
+      "breakpoints": true
+    },
+    {
+      "idx": 17,
+      "version": "7",
+      "when": 1777268853484,
+      "tag": "0017_property_parent_check",
+      "breakpoints": true
+    },
+    {
+      "idx": 18,
+      "version": "7",
+      "when": 1777268985448,
+      "tag": "0018_checklist_scope_property",
+      "breakpoints": true
     }
   ]
 }

src/lib/server/db/schema/_shared.ts

@@ -33,7 +33,8 @@ export const checklistScopeEnum = pgEnum('checklist_scope', [
 	'task',
 	'subtask',
 	'maintenance_event',
-	'ad_hoc'
+	'ad_hoc',
+	'property'
 ]);
 export const docScopeEnum = pgEnum('doc_scope', [
 	'project',

src/lib/server/db/schema/properties.ts

@@ -1,3 +1,4 @@
+import type { AnyPgColumn } from 'drizzle-orm/pg-core';
 import { pgTable, varchar, text, numeric, index } from 'drizzle-orm/pg-core';
 import { companies, users } from './tenancy';
 import { pk, fk, createdAt, updatedAt, deletedAt } from './_shared';
@@ -9,6 +10,13 @@ export const properties = pgTable(
 		companyId: fk('company_id')
 			.notNull()
 			.references(() => companies.id, { onDelete: 'cascade' }),
+		// NULL = root. References another property in the same company. Use cases:
+		// a building owns its apartments, a campus owns its sub-buildings.
+		// Cross-company references and cycles are blocked at the service layer
+		// (see assertNoCycle / setParent in services/properties.ts).
+		parentId: fk('parent_id').references((): AnyPgColumn => properties.id, {
+			onDelete: 'restrict'
+		}),
 		name: varchar('name', { length: 255 }).notNull(),
 		kind: varchar('kind', { length: 64 }), // warehouse, office, datacenter, ...
 		addressLine1: varchar('address_line1', { length: 255 }),
@@ -26,7 +34,8 @@ export const properties = pgTable(
 		deletedAt: deletedAt()
 	},
 	(t) => ({
-		byCompany: index('properties_by_company').on(t.companyId)
+		byCompany: index('properties_by_company').on(t.companyId),
+		byParent: index('properties_by_parent').on(t.companyId, t.parentId)
 	})
 );
 

src/lib/server/services/assets.ts

@@ -1,4 +1,4 @@
-import { and, asc, desc, eq, isNull, or, sql } from 'drizzle-orm';
+import { and, asc, desc, eq, inArray, isNull, or, sql } from 'drizzle-orm';
 import { db } from '$lib/server/db/client';
 import {
 	assets,
@@ -292,7 +292,10 @@ export async function appendAssetLog(
 export interface AssetListOptions {
 	companyId: string;
 	typeSlug?: string;
+	/** Restrict to a single property. Mutually exclusive with `propertyIds`. */
 	propertyId?: string;
+	/** Restrict to assets at any of these properties (e.g. a property tree). */
+	propertyIds?: string[];
 	projectId?: string;
 	roomId?: string;
 	q?: string;
@@ -302,7 +305,11 @@ export interface AssetListOptions {
 
 export async function listAssets(opts: AssetListOptions) {
 	const where = [eq(assets.companyId, opts.companyId), isNull(assets.deletedAt)];
-	if (opts.propertyId) where.push(eq(assets.currentPropertyId, opts.propertyId));
+	if (opts.propertyIds && opts.propertyIds.length > 0) {
+		where.push(inArray(assets.currentPropertyId, opts.propertyIds));
+	} else if (opts.propertyId) {
+		where.push(eq(assets.currentPropertyId, opts.propertyId));
+	}
 	if (opts.projectId) where.push(eq(assets.currentProjectId, opts.projectId));
 	if (opts.roomId) where.push(eq(assets.currentRoomId, opts.roomId));
 	if (opts.typeSlug) {

src/lib/server/services/checklists.ts

@@ -1,4 +1,4 @@
-import { and, asc, desc, eq, isNull, sql } from 'drizzle-orm';
+import { and, asc, desc, eq, inArray, isNull, sql } from 'drizzle-orm';
 import { db } from '$lib/server/db/client';
 import {
 	checklistInstances,
@@ -9,7 +9,12 @@ import {
 	type ChecklistTemplateItem
 } from '$lib/server/db/schema/checklists';
 
-export type ChecklistScope = 'task' | 'subtask' | 'maintenance_event' | 'ad_hoc';
+export type ChecklistScope =
+	| 'task'
+	| 'subtask'
+	| 'maintenance_event'
+	| 'ad_hoc'
+	| 'property';
 
 // --- templates ---------------------------------------------------------------
 
@@ -252,3 +257,25 @@ export async function listInstancesForScope(
 		)
 		.orderBy(desc(checklistInstances.createdAt));
 }
+
+/**
+ * Checklist instances scoped to any of the given property ids. Used by the
+ * property roll-up tab when "include sub-properties" is on.
+ */
+export async function listInstancesForProperties(
+	companyId: string,
+	propertyIds: string[]
+) {
+	if (propertyIds.length === 0) return [];
+	return db
+		.select()
+		.from(checklistInstances)
+		.where(
+			and(
+				eq(checklistInstances.companyId, companyId),
+				eq(checklistInstances.scopeType, 'property'),
+				inArray(checklistInstances.scopeId, propertyIds)
+			)
+		)
+		.orderBy(desc(checklistInstances.createdAt));
+}

src/lib/server/services/expenses.ts

@@ -165,7 +165,21 @@ export async function listExpensesForProperty(
 	opts: { kinds?: ExpenseKind[]; limit?: number } = {}
 ): Promise<PropertyExpense[]> {
 	await assertProperty(companyId, propertyId);
-	const where = [eq(propertyExpenses.propertyId, propertyId)];
+	return listExpensesForProperties([propertyId], opts);
+}
+
+/**
+ * Tree-aware list. Caller resolves descendants via getDescendantIds (in
+ * services/properties) and passes the full id array. No per-property auth
+ * check — caller is responsible for ensuring every id belongs to the active
+ * company. Empty array returns [].
+ */
+export async function listExpensesForProperties(
+	propertyIds: string[],
+	opts: { kinds?: ExpenseKind[]; limit?: number } = {}
+): Promise<PropertyExpense[]> {
+	if (propertyIds.length === 0) return [];
+	const where = [inArray(propertyExpenses.propertyId, propertyIds)];
 	if (opts.kinds && opts.kinds.length > 0) {
 		where.push(inArray(propertyExpenses.kind, opts.kinds));
 	}
@@ -199,7 +213,18 @@ export async function monthlySeriesForProperty(
 	months: ChartRange = 12
 ): Promise<MonthlySeriesPoint[]> {
 	await assertProperty(companyId, propertyId);
-	if (kinds.length === 0) return [];
+	return monthlySeriesForProperties([propertyId], kinds, months);
+}
+
+/**
+ * Tree-aware monthly series. Caller passes the resolved id array.
+ */
+export async function monthlySeriesForProperties(
+	propertyIds: string[],
+	kinds: ExpenseKind[],
+	months: ChartRange = 12
+): Promise<MonthlySeriesPoint[]> {
+	if (propertyIds.length === 0 || kinds.length === 0) return [];
 
 	const now = new Date();
 	const thisMonthStart = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), 1));
@@ -214,7 +239,7 @@ export async function monthlySeriesForProperty(
 			.from(propertyExpenses)
 			.where(
 				and(
-					eq(propertyExpenses.propertyId, propertyId),
+					inArray(propertyExpenses.propertyId, propertyIds),
 					inArray(propertyExpenses.kind, kinds)
 				)
 			);
@@ -241,7 +266,7 @@ export async function monthlySeriesForProperty(
 		.from(propertyExpenses)
 		.where(
 			and(
-				eq(propertyExpenses.propertyId, propertyId),
+				inArray(propertyExpenses.propertyId, propertyIds),
 				inArray(propertyExpenses.kind, kinds),
 				gte(propertyExpenses.incurredAt, start),
 				lt(propertyExpenses.incurredAt, new Date(Date.UTC(thisMonthStart.getUTCFullYear(), thisMonthStart.getUTCMonth() + 1, 1)))
@@ -279,6 +304,25 @@ export async function summaryForProperty(
 	currency: string | null;
 }> {
 	await assertProperty(companyId, propertyId);
+	return summaryForProperties([propertyId], days);
+}
+
+/**
+ * Tree-aware summary. Caller passes resolved id array. When children carry
+ * different currencies, `currency` is null — the UI groups by currency in
+ * that case rather than auto-converting.
+ */
+export async function summaryForProperties(
+	propertyIds: string[],
+	days = 365
+): Promise<{
+	byKind: Partial<Record<ExpenseKind, number>>;
+	grandTotal: number;
+	currency: string | null;
+}> {
+	if (propertyIds.length === 0) {
+		return { byKind: {}, grandTotal: 0, currency: null };
+	}
 	const since = new Date(Date.now() - days * 86_400_000);
 	const rows = await db
 		.select({
@@ -289,7 +333,7 @@ export async function summaryForProperty(
 		.from(propertyExpenses)
 		.where(
 			and(
-				eq(propertyExpenses.propertyId, propertyId),
+				inArray(propertyExpenses.propertyId, propertyIds),
 				gte(propertyExpenses.incurredAt, since)
 			)
 		)

src/lib/server/services/maintenance.ts

@@ -1,5 +1,5 @@
 import { addDays, addHours, addMonths, addYears } from 'date-fns';
-import { and, asc, desc, eq, isNotNull, lte, sql } from 'drizzle-orm';
+import { and, asc, desc, eq, inArray, isNotNull, lte, sql } from 'drizzle-orm';
 import { db } from '$lib/server/db/client';
 import { assets } from '$lib/server/db/schema/assets';
 import {
@@ -349,6 +349,77 @@ export async function listDueAndOverdue(opts: OverdueOpts) {
 		.limit(opts.limit ?? 50);
 }
 
+// --- property-tree readers --------------------------------------------------
+
+/**
+ * Maintenance schedules for assets currently located at any of the given
+ * properties. Caller passes a property id array (e.g. expanded via
+ * getDescendantIds).
+ */
+export async function listSchedulesForProperties(companyId: string, propertyIds: string[]) {
+	if (propertyIds.length === 0) return [];
+	return db
+		.select({
+			id: maintenanceSchedules.id,
+			name: maintenanceSchedules.name,
+			kind: maintenanceSchedules.kind,
+			active: maintenanceSchedules.active,
+			intervalValue: maintenanceSchedules.intervalValue,
+			intervalUnit: maintenanceSchedules.intervalUnit,
+			lastServicedAt: maintenanceSchedules.lastServicedAt,
+			nextDueAt: maintenanceSchedules.nextDueAt,
+			nextDueUsage: maintenanceSchedules.nextDueUsage,
+			assetId: maintenanceSchedules.assetId,
+			assetName: assets.name,
+			propertyId: assets.currentPropertyId
+		})
+		.from(maintenanceSchedules)
+		.innerJoin(assets, eq(assets.id, maintenanceSchedules.assetId))
+		.where(
+			and(
+				eq(assets.companyId, companyId),
+				inArray(assets.currentPropertyId, propertyIds)
+			)
+		)
+		.orderBy(desc(maintenanceSchedules.active), asc(maintenanceSchedules.nextDueAt));
+}
+
+/**
+ * Maintenance events for assets at any of the given properties. Recent first.
+ */
+export async function listEventsForProperties(
+	companyId: string,
+	propertyIds: string[],
+	limit = 200
+) {
+	if (propertyIds.length === 0) return [];
+	return db
+		.select({
+			id: maintenanceEvents.id,
+			scheduleId: maintenanceEvents.scheduleId,
+			scheduleName: maintenanceSchedules.name,
+			performedAt: maintenanceEvents.performedAt,
+			performedBy: maintenanceEvents.performedBy,
+			notes: maintenanceEvents.notes,
+			usageReading: maintenanceEvents.usageReading,
+			checklistInstanceId: maintenanceEvents.checklistInstanceId,
+			assetId: maintenanceEvents.assetId,
+			assetName: assets.name,
+			propertyId: assets.currentPropertyId
+		})
+		.from(maintenanceEvents)
+		.innerJoin(assets, eq(assets.id, maintenanceEvents.assetId))
+		.leftJoin(maintenanceSchedules, eq(maintenanceSchedules.id, maintenanceEvents.scheduleId))
+		.where(
+			and(
+				eq(assets.companyId, companyId),
+				inArray(assets.currentPropertyId, propertyIds)
+			)
+		)
+		.orderBy(desc(maintenanceEvents.performedAt))
+		.limit(limit);
+}
+
 export async function countOverdueForCompany(companyId: string): Promise<number> {
 	const [row] = await db
 		.select({ n: sql<number>`count(*)::int` })

src/lib/server/services/properties.ts

@@ -7,6 +7,7 @@ export interface PropertyCreateInput {
 	createdBy: string;
 	name: string;
 	kind?: string | null;
+	parentId?: string | null;
 	addressLine1?: string | null;
 	addressLine2?: string | null;
 	city?: string | null;
@@ -16,9 +17,28 @@ export interface PropertyCreateInput {
 	notes?: string | null;
 }
 
+async function assertParentInCompany(companyId: string, parentId: string): Promise<void> {
+	const [row] = await db
+		.select({ id: properties.id })
+		.from(properties)
+		.where(
+			and(
+				eq(properties.id, parentId),
+				eq(properties.companyId, companyId),
+				isNull(properties.deletedAt)
+			)
+		)
+		.limit(1);
+	if (!row) throw new Error('parent property not found in this company');
+}
+
 export async function createProperty(input: PropertyCreateInput): Promise<{ id: string }> {
+	if (input.parentId) {
+		await assertParentInCompany(input.companyId, input.parentId);
+	}
 	const values: NewProperty = {
 		companyId: input.companyId,
+		parentId: input.parentId ?? null,
 		name: input.name.trim(),
 		kind: input.kind ?? null,
 		addressLine1: input.addressLine1 ?? null,
@@ -62,11 +82,17 @@ export async function updateProperty(
 	id: string,
 	patch: Partial<PropertyCreateInput>
 ): Promise<void> {
+	if (patch.parentId !== undefined && patch.parentId !== null) {
+		if (patch.parentId === id) throw new Error('a property cannot be its own parent');
+		await assertParentInCompany(companyId, patch.parentId);
+		await assertNoCycle(companyId, id, patch.parentId);
+	}
 	await db
 		.update(properties)
 		.set({
 			...(patch.name !== undefined && { name: patch.name.trim() }),
 			...(patch.kind !== undefined && { kind: patch.kind ?? null }),
+			...(patch.parentId !== undefined && { parentId: patch.parentId ?? null }),
 			...(patch.addressLine1 !== undefined && { addressLine1: patch.addressLine1 ?? null }),
 			...(patch.addressLine2 !== undefined && { addressLine2: patch.addressLine2 ?? null }),
 			...(patch.city !== undefined && { city: patch.city ?? null }),
@@ -81,8 +107,96 @@ export async function updateProperty(
 }
 
 export async function softDeleteProperty(companyId: string, id: string): Promise<void> {
+	// Block delete when live children exist — orphaning to root would silently
+	// disconnect roll-up reports. Caller should detach children first if that's
+	// the intent.
+	const [child] = await db
+		.select({ id: properties.id })
+		.from(properties)
+		.where(
+			and(
+				eq(properties.parentId, id),
+				eq(properties.companyId, companyId),
+				isNull(properties.deletedAt)
+			)
+		)
+		.limit(1);
+	if (child) throw new Error('detach or delete sub-properties first');
+
 	await db
 		.update(properties)
 		.set({ deletedAt: sql`now()` })
 		.where(and(eq(properties.id, id), eq(properties.companyId, companyId)));
 }
+
+// --- Hierarchy helpers -------------------------------------------------------
+
+/**
+ * Returns [propertyId, ...all descendants] using a recursive CTE. The result
+ * always includes the root id so callers can use it directly with
+ * `WHERE property_id = ANY($ids)` for roll-up queries.
+ *
+ * Bounded by `deleted_at IS NULL` and `company_id = $companyId` to avoid
+ * leaking cross-company rows even if a service caller goofs.
+ */
+export async function getDescendantIds(
+	companyId: string,
+	propertyId: string
+): Promise<string[]> {
+	const rows = await db.execute<{ id: string }>(sql`
+		WITH RECURSIVE tree AS (
+			SELECT id FROM properties
+				WHERE id = ${propertyId}
+					AND company_id = ${companyId}
+					AND deleted_at IS NULL
+			UNION ALL
+			SELECT p.id FROM properties p
+				INNER JOIN tree t ON p.parent_id = t.id
+				WHERE p.company_id = ${companyId}
+					AND p.deleted_at IS NULL
+		)
+		SELECT id FROM tree
+	`);
+	return rows.rows.map((r) => r.id);
+}
+
+/**
+ * Walk parent_id from `propertyId` up to the root. Used by assertNoCycle
+ * to detect attempts at moving a property under one of its own descendants.
+ */
+export async function getAncestorIds(
+	companyId: string,
+	propertyId: string
+): Promise<string[]> {
+	const rows = await db.execute<{ id: string }>(sql`
+		WITH RECURSIVE chain AS (
+			SELECT id, parent_id FROM properties
+				WHERE id = ${propertyId} AND company_id = ${companyId}
+			UNION ALL
+			SELECT p.id, p.parent_id FROM properties p
+				INNER JOIN chain c ON p.id = c.parent_id
+				WHERE p.company_id = ${companyId}
+		)
+		SELECT id FROM chain WHERE id <> ${propertyId}
+	`);
+	return rows.rows.map((r) => r.id);
+}
+
+/**
+ * Throws if assigning `candidateParentId` as the parent of `propertyId` would
+ * create a cycle (i.e. candidateParentId is propertyId itself or one of its
+ * descendants).
+ */
+export async function assertNoCycle(
+	companyId: string,
+	propertyId: string,
+	candidateParentId: string
+): Promise<void> {
+	if (candidateParentId === propertyId) {
+		throw new Error('a property cannot be its own parent');
+	}
+	const descendants = await getDescendantIds(companyId, propertyId);
+	if (descendants.includes(candidateParentId)) {
+		throw new Error('cannot set parent: that property is already a descendant');
+	}
+}

src/routes/(app)/properties/[id]/+layout.server.ts

@@ -1,4 +1,7 @@
 import { error } from '@sveltejs/kit';
+import { and, eq, isNull, sql } from 'drizzle-orm';
+import { db } from '$lib/server/db/client';
+import { properties } from '$lib/server/db/schema/properties';
 import { getProperty } from '$lib/server/services/properties';
 import type { LayoutServerLoad } from './$types';
 
@@ -6,5 +9,40 @@ export const load: LayoutServerLoad = async ({ locals, params }) => {
 	if (!locals.company) throw error(400, 'No active company');
 	const property = await getProperty(locals.company.id, params.id);
 	if (!property) throw error(404, 'Property not found');
-	return { property };
+
+	// Fetch parent (for the breadcrumb) and the child count (for the tab badge)
+	// in a single round trip each — both are tiny single-row queries.
+	const [parent, childCountRow] = await Promise.all([
+		property.parentId
+			? db
+					.select({ id: properties.id, name: properties.name })
+					.from(properties)
+					.where(
+						and(
+							eq(properties.id, property.parentId),
+							eq(properties.companyId, locals.company.id),
+							isNull(properties.deletedAt)
+						)
+					)
+					.limit(1)
+					.then((r) => r[0] ?? null)
+			: Promise.resolve(null),
+		db
+			.select({ n: sql<number>`count(*)::int` })
+			.from(properties)
+			.where(
+				and(
+					eq(properties.parentId, property.id),
+					eq(properties.companyId, locals.company.id),
+					isNull(properties.deletedAt)
+				)
+			)
+			.then((r) => r[0])
+	]);
+
+	return {
+		property,
+		parent,
+		childCount: childCountRow?.n ?? 0
+	};
 };

src/routes/(app)/properties/[id]/+layout.svelte

@@ -7,10 +7,16 @@
 
 	const tabs = $derived([
 		{ href: `/properties/${data.property.id}`, label: 'Overview' },
+		{
+			href: `/properties/${data.property.id}/sub-properties`,
+			label: data.childCount > 0 ? `Sub-properties (${data.childCount})` : 'Sub-properties'
+		},
 		{ href: `/properties/${data.property.id}/rooms`, label: 'Rooms' },
 		{ href: `/properties/${data.property.id}/assets`, label: 'Assets' },
 		{ href: `/properties/${data.property.id}/accounts`, label: 'Accounts' },
 		{ href: `/properties/${data.property.id}/expenses`, label: 'Expenses' },
+		{ href: `/properties/${data.property.id}/maintenance`, label: 'Maintenance' },
+		{ href: `/properties/${data.property.id}/todos`, label: 'Todos' },
 		{ href: `/properties/${data.property.id}/documents`, label: 'Documents' }
 	]);
 </script>
@@ -18,9 +24,19 @@
 <div class="space-y-6">
 	<div class="flex items-start justify-between gap-4">
 		<div class="min-w-0">
-			<div class="text-xs uppercase tracking-wider text-gray-400 dark:text-gray-500">
+			{#if data.parent}
-				{data.property.kind ?? 'Property'}
+				<nav aria-label="Breadcrumb" class="text-xs text-gray-500 dark:text-gray-400">
-			</div>
+					<a href="/properties/{data.parent.id}" class="hover:text-gray-700 dark:hover:text-gray-200">
+						{data.parent.name}
+					</a>
+					<span class="mx-1.5">›</span>
+					<span class="text-gray-700 dark:text-gray-300">{data.property.name}</span>
+				</nav>
+			{:else}
+				<div class="text-xs uppercase tracking-wider text-gray-400 dark:text-gray-500">
+					{data.property.kind ?? 'Property'}
+				</div>
+			{/if}
 			<h1 class="truncate text-2xl font-semibold text-gray-900 dark:text-gray-100">
 				{data.property.name}
 			</h1>

src/routes/(app)/properties/[id]/+page.server.ts

@@ -1,12 +1,19 @@
-import { error, fail } from '@sveltejs/kit';
+import { error, fail, redirect } from '@sveltejs/kit';
+import { and, eq, isNull, ne, notInArray } from 'drizzle-orm';
 import { z } from 'zod';
-import { updateProperty, softDeleteProperty } from '$lib/server/services/properties';
+import { db } from '$lib/server/db/client';
-import { redirect } from '@sveltejs/kit';
+import { properties } from '$lib/server/db/schema/properties';
-import type { Actions } from './$types';
+import {
+	getDescendantIds,
+	softDeleteProperty,
+	updateProperty
+} from '$lib/server/services/properties';
+import type { Actions, PageServerLoad } from './$types';
 
 const PatchSchema = z.object({
 	name: z.string().trim().min(1).max(255),
 	kind: z.string().trim().max(64).optional().or(z.literal('')),
+	parentId: z.string().uuid().optional().or(z.literal('')),
 	addressLine1: z.string().trim().max(255).optional().or(z.literal('')),
 	addressLine2: z.string().trim().max(255).optional().or(z.literal('')),
 	city: z.string().trim().max(128).optional().or(z.literal('')),
@@ -18,6 +25,28 @@ const PatchSchema = z.object({
 
 const e2n = (s: string | undefined) => (!s ? null : s);
 
+export const load: PageServerLoad = async ({ locals, params }) => {
+	if (!locals.company) throw error(400, 'No active company');
+	// Eligible parents = all live properties in the company minus this one
+	// and its descendants. Excluding descendants is what blocks the user from
+	// creating a cycle through the picker; the service layer's assertNoCycle
+	// is the belt-and-braces guard.
+	const exclude = await getDescendantIds(locals.company.id, params.id);
+	const eligibleParents = await db
+		.select({ id: properties.id, name: properties.name })
+		.from(properties)
+		.where(
+			and(
+				eq(properties.companyId, locals.company.id),
+				isNull(properties.deletedAt),
+				ne(properties.id, params.id),
+				exclude.length > 0 ? notInArray(properties.id, exclude) : undefined
+			)
+		)
+		.orderBy(properties.name);
+	return { eligibleParents };
+};
+
 export const actions: Actions = {
 	save: async ({ request, locals, params }) => {
 		if (!locals.company) throw error(401);
@@ -28,22 +57,31 @@ export const actions: Actions = {
 			return fail(400, { error: parsed.error.errors[0]?.message ?? 'Invalid input' });
 		}
 		const v = parsed.data;
-		await updateProperty(locals.company.id, params.id, {
+		try {
-			name: v.name,
+			await updateProperty(locals.company.id, params.id, {
-			kind: e2n(v.kind),
+				name: v.name,
-			addressLine1: e2n(v.addressLine1),
+				kind: e2n(v.kind),
-			addressLine2: e2n(v.addressLine2),
+				parentId: v.parentId ? v.parentId : null,
-			city: e2n(v.city),
+				addressLine1: e2n(v.addressLine1),
-			region: e2n(v.region),
+				addressLine2: e2n(v.addressLine2),
-			postalCode: e2n(v.postalCode),
+				city: e2n(v.city),
-			countryCode: e2n(v.countryCode),
+				region: e2n(v.region),
-			notes: e2n(v.notes)
+				postalCode: e2n(v.postalCode),
-		});
+				countryCode: e2n(v.countryCode),
+				notes: e2n(v.notes)
+			});
+		} catch (e) {
+			return fail(400, { error: (e as Error).message });
+		}
 		return { ok: true };
 	},
 	delete: async ({ locals, params }) => {
 		if (!locals.company) throw error(401);
-		await softDeleteProperty(locals.company.id, params.id);
+		try {
+			await softDeleteProperty(locals.company.id, params.id);
+		} catch (e) {
+			return fail(400, { error: (e as Error).message });
+		}
 		throw redirect(303, '/properties');
 	}
 };

src/routes/(app)/properties/[id]/+page.svelte

@@ -34,6 +34,19 @@
 			<input id="kind" name="kind" value={p.kind ?? ''}
 				class="mt-1 block w-full rounded-md border border-gray-300 bg-white px-3 py-2 text-sm shadow-sm focus:border-primary-500 focus:outline-none focus:ring-1 focus:ring-primary-500 dark:border-gray-600 dark:bg-gray-900 dark:text-gray-100" />
 		</div>
+		<div class="sm:col-span-2">
+			<label for="parentId" class="block text-sm font-medium text-gray-700 dark:text-gray-300">Parent property</label>
+			<select id="parentId" name="parentId"
+				class="mt-1 block w-full rounded-md border border-gray-300 bg-white px-3 py-2 text-sm shadow-sm focus:border-primary-500 focus:outline-none focus:ring-1 focus:ring-primary-500 dark:border-gray-600 dark:bg-gray-900 dark:text-gray-100">
+				<option value="">— Top level (no parent) —</option>
+				{#each data.eligibleParents as opt (opt.id)}
+					<option value={opt.id} selected={opt.id === p.parentId}>{opt.name}</option>
+				{/each}
+			</select>
+			<p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+				Sub-properties (e.g. apartments inside a building) inherit roll-up totals from their parent.
+			</p>
+		</div>
 		<div>
 			<label for="countryCode" class="block text-sm font-medium text-gray-700 dark:text-gray-300">Country (ISO 2)</label>
 			<input id="countryCode" name="countryCode" maxlength="2" value={p.countryCode ?? ''}

src/routes/(app)/properties/[id]/assets/+page.server.ts

@@ -1,9 +1,14 @@
 import { error } from '@sveltejs/kit';
 import { listAssets } from '$lib/server/services/assets';
+import { getDescendantIds } from '$lib/server/services/properties';
 import type { PageServerLoad } from './$types';
 
-export const load: PageServerLoad = async ({ locals, params }) => {
+export const load: PageServerLoad = async ({ locals, params, url }) => {
 	if (!locals.company) throw error(401);
-	const rows = await listAssets({ companyId: locals.company.id, propertyId: params.id });
+	const includeDescendants = url.searchParams.get('descendants') === '1';
-	return { assets: rows };
+	const propertyIds = includeDescendants
+		? await getDescendantIds(locals.company.id, params.id)
+		: [params.id];
+	const rows = await listAssets({ companyId: locals.company.id, propertyIds });
+	return { assets: rows, includeDescendants, descendantCount: propertyIds.length };
 };

src/routes/(app)/properties/[id]/assets/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import type { PageData } from './$types';
-	let { data }: { data: PageData } = $props();
+	import type { LayoutData } from '../$types';
+	let { data }: { data: PageData & LayoutData } = $props();
 	const propId = $derived(data.property.id);
 
 	// Group assets by their room (including an "Unassigned" bucket).
@@ -31,8 +32,37 @@
 </script>
 
 <div class="space-y-4">
+	{#if data.childCount > 0}
+		<div class="flex flex-wrap items-center justify-between gap-3 rounded-lg border border-gray-200 bg-white px-4 py-2.5 text-sm dark:border-gray-700 dark:bg-gray-800">
+			<div class="text-gray-700 dark:text-gray-300">
+				{#if data.includeDescendants}
+					<span class="font-medium">{data.property.name}</span> + sub-properties
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.descendantCount} total)</span>
+				{:else}
+					<span class="font-medium">{data.property.name}</span>
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.childCount} sub-properties hidden)</span>
+				{/if}
+			</div>
+			<div role="tablist" class="inline-flex rounded-md border border-gray-200 bg-gray-50 p-0.5 text-xs font-medium dark:border-gray-700 dark:bg-gray-900">
+				{#each [{ v: '', l: 'This property' }, { v: '1', l: 'Include sub-properties' }] as opt}
+					{@const active = (data.includeDescendants ? '1' : '') === opt.v}
+					<a
+						role="tab"
+						href={opt.v ? '?descendants=1' : '?'}
+						aria-selected={active}
+						class="rounded px-2 py-1 transition {active
+							? 'bg-white text-gray-900 shadow-sm dark:bg-gray-700 dark:text-gray-100'
+							: 'text-gray-600 hover:text-gray-900 dark:text-gray-400 dark:hover:text-gray-100'}"
+					>
+						{opt.l}
+					</a>
+				{/each}
+			</div>
+		</div>
+	{/if}
+
 	<div class="flex items-center justify-between">
-		<p class="text-sm text-gray-500 dark:text-gray-400">{data.assets.length} asset{data.assets.length === 1 ? '' : 's'} at this property.</p>
+		<p class="text-sm text-gray-500 dark:text-gray-400">{data.assets.length} asset{data.assets.length === 1 ? '' : 's'}{data.includeDescendants ? ' across the property tree' : ' at this property'}.</p>
 		<a href="/assets/new?property={propId}" class="rounded-md bg-primary-600 px-3 py-1.5 text-sm font-medium text-white hover:bg-primary-700">+ Add asset</a>
 	</div>
 

src/routes/(app)/properties/[id]/expenses/+page.server.ts

@@ -8,13 +8,14 @@ import { companies } from '$lib/server/db/schema/tenancy';
 import {
 	createExpense,
 	deleteExpense,
-	listExpensesForProperty,
+	listExpensesForProperties,
-	monthlySeriesForProperty,
+	monthlySeriesForProperties,
-	summaryForProperty,
+	summaryForProperties,
 	updateExpense,
 	type ChartRange,
 	type ExpenseKind
 } from '$lib/server/services/expenses';
+import { getDescendantIds } from '$lib/server/services/properties';
 import type { Actions, PageServerLoad } from './$types';
 
 const KINDS = [
@@ -70,8 +71,17 @@ function parseRange(raw: string | null): ChartRange {
 export const load: PageServerLoad = async ({ locals, params, url }) => {
 	const { company } = requireCompany(locals);
 	const range = parseRange(url.searchParams.get('range'));
+	const includeDescendants = url.searchParams.get('descendants') === '1';
+
+	// Single-property reads still go through `[params.id]`; tree reads expand via
+	// the recursive CTE in services/properties. The query already validates the
+	// company scope on every descendant.
+	const propertyIds = includeDescendants
+		? await getDescendantIds(company.id, params.id)
+		: [params.id];
+
 	const [expenses, accounts, series, summary, [companyRow]] = await Promise.all([
-		listExpensesForProperty(company.id, params.id),
+		listExpensesForProperties(propertyIds),
 		db
 			.select({
 				id: propertyAccounts.id,
@@ -82,8 +92,8 @@ export const load: PageServerLoad = async ({ locals, params, url }) => {
 			})
 			.from(propertyAccounts)
 			.where(eq(propertyAccounts.propertyId, params.id)),
-		monthlySeriesForProperty(company.id, params.id, ['electricity', 'water'], range),
+		monthlySeriesForProperties(propertyIds, ['electricity', 'water'], range),
-		summaryForProperty(company.id, params.id, 365),
+		summaryForProperties(propertyIds, 365),
 		db.select({ settings: companies.settings }).from(companies).where(eq(companies.id, company.id)).limit(1)
 	]);
 	const defaultCurrency = parseSettings(companyRow?.settings ?? null).default_currency ?? 'USD';
@@ -93,7 +103,9 @@ export const load: PageServerLoad = async ({ locals, params, url }) => {
 		chartSeries: series,
 		chartRange: range,
 		summary,
-		defaultCurrency
+		defaultCurrency,
+		includeDescendants,
+		descendantCount: propertyIds.length
 	};
 };
 

src/routes/(app)/properties/[id]/expenses/+page.svelte

@@ -3,8 +3,23 @@
 	import ExpenseChart from '$lib/components/ExpenseChart.svelte';
 	import { EXPENSE_KINDS, EXPENSE_KIND_LABEL, type ExpenseKind } from '$lib/expenses';
 	import type { PageData, ActionData } from './$types';
+	import type { LayoutData } from '../$types';
 
-	let { data, form }: { data: PageData; form: ActionData } = $props();
+	let { data, form }: { data: PageData & LayoutData; form: ActionData } = $props();
+
+	function withParams(extra: Record<string, string | undefined>): string {
+		const params = new URLSearchParams();
+		const base = {
+			range: String(data.chartRange),
+			descendants: data.includeDescendants ? '1' : ''
+		} as Record<string, string>;
+		const merged = { ...base, ...extra };
+		for (const [k, v] of Object.entries(merged)) {
+			if (v) params.set(k, v);
+		}
+		const qs = params.toString();
+		return qs ? `?${qs}` : '?';
+	}
 
 	let showForm = $state(false);
 	let editingId = $state<string | null>(null);
@@ -39,6 +54,35 @@
 </script>
 
 <div class="space-y-6">
+	{#if data.childCount > 0}
+		<div class="flex flex-wrap items-center justify-between gap-3 rounded-lg border border-gray-200 bg-white px-4 py-2.5 text-sm dark:border-gray-700 dark:bg-gray-800">
+			<div class="text-gray-700 dark:text-gray-300">
+				{#if data.includeDescendants}
+					<span class="font-medium">{data.property.name}</span> + sub-properties
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.descendantCount} total)</span>
+				{:else}
+					<span class="font-medium">{data.property.name}</span>
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.childCount} sub-properties hidden)</span>
+				{/if}
+			</div>
+			<div role="tablist" class="inline-flex rounded-md border border-gray-200 bg-gray-50 p-0.5 text-xs font-medium dark:border-gray-700 dark:bg-gray-900">
+				{#each [{ v: '', l: 'This property' }, { v: '1', l: 'Include sub-properties' }] as opt}
+					{@const active = (data.includeDescendants ? '1' : '') === opt.v}
+					<a
+						role="tab"
+						href={withParams({ descendants: opt.v || undefined })}
+						aria-selected={active}
+						class="rounded px-2 py-1 transition {active
+							? 'bg-white text-gray-900 shadow-sm dark:bg-gray-700 dark:text-gray-100'
+							: 'text-gray-600 hover:text-gray-900 dark:text-gray-400 dark:hover:text-gray-100'}"
+					>
+						{opt.l}
+					</a>
+				{/each}
+			</div>
+		</div>
+	{/if}
+
 	<!-- Chart: electricity + water -->
 	<section class="rounded-lg border border-gray-200 bg-white p-4 dark:border-gray-700 dark:bg-gray-800">
 		<div class="mb-3 flex flex-wrap items-baseline justify-between gap-3">
@@ -52,7 +96,7 @@
 						{@const active = String(data.chartRange) === String(opt.v)}
 						<a
 							role="tab"
-							href="?range={opt.v}"
+							href={withParams({ range: String(opt.v) })}
 							aria-selected={active}
 							class="rounded px-2 py-1 transition {active
 								? 'bg-white text-gray-900 shadow-sm dark:bg-gray-700 dark:text-gray-100'

src/routes/(app)/properties/[id]/maintenance/+page.server.ts

@@ -0,0 +1,25 @@
+import { error } from '@sveltejs/kit';
+import {
+	listEventsForProperties,
+	listSchedulesForProperties
+} from '$lib/server/services/maintenance';
+import { getDescendantIds } from '$lib/server/services/properties';
+import type { PageServerLoad } from './$types';
+
+export const load: PageServerLoad = async ({ locals, params, url }) => {
+	if (!locals.company) throw error(401);
+	const includeDescendants = url.searchParams.get('descendants') === '1';
+	const propertyIds = includeDescendants
+		? await getDescendantIds(locals.company.id, params.id)
+		: [params.id];
+	const [schedules, events] = await Promise.all([
+		listSchedulesForProperties(locals.company.id, propertyIds),
+		listEventsForProperties(locals.company.id, propertyIds)
+	]);
+	return {
+		schedules,
+		events,
+		includeDescendants,
+		descendantCount: propertyIds.length
+	};
+};

src/routes/(app)/properties/[id]/maintenance/+page.svelte

@@ -0,0 +1,127 @@
+<script lang="ts">
+	import type { PageData } from './$types';
+	import type { LayoutData } from '../$types';
+
+	let { data }: { data: PageData & LayoutData } = $props();
+
+	function fmtDate(d: Date | string | null | undefined): string {
+		if (!d) return '—';
+		const dt = typeof d === 'string' ? new Date(d) : d;
+		return Number.isNaN(dt.getTime()) ? '—' : dt.toISOString().slice(0, 10);
+	}
+
+	const overdue = $derived(
+		data.schedules.filter((s) => s.active && s.nextDueAt && new Date(s.nextDueAt) < new Date())
+	);
+	const upcoming = $derived(
+		data.schedules.filter((s) => s.active && !overdue.includes(s))
+	);
+</script>
+
+<div class="space-y-4">
+	{#if data.childCount > 0}
+		<div class="flex flex-wrap items-center justify-between gap-3 rounded-lg border border-gray-200 bg-white px-4 py-2.5 text-sm dark:border-gray-700 dark:bg-gray-800">
+			<div class="text-gray-700 dark:text-gray-300">
+				{#if data.includeDescendants}
+					<span class="font-medium">{data.property.name}</span> + sub-properties
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.descendantCount} total)</span>
+				{:else}
+					<span class="font-medium">{data.property.name}</span>
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.childCount} sub-properties hidden)</span>
+				{/if}
+			</div>
+			<div role="tablist" class="inline-flex rounded-md border border-gray-200 bg-gray-50 p-0.5 text-xs font-medium dark:border-gray-700 dark:bg-gray-900">
+				{#each [{ v: '', l: 'This property' }, { v: '1', l: 'Include sub-properties' }] as opt}
+					{@const active = (data.includeDescendants ? '1' : '') === opt.v}
+					<a
+						role="tab"
+						href={opt.v ? '?descendants=1' : '?'}
+						aria-selected={active}
+						class="rounded px-2 py-1 transition {active
+							? 'bg-white text-gray-900 shadow-sm dark:bg-gray-700 dark:text-gray-100'
+							: 'text-gray-600 hover:text-gray-900 dark:text-gray-400 dark:hover:text-gray-100'}"
+					>
+						{opt.l}
+					</a>
+				{/each}
+			</div>
+		</div>
+	{/if}
+
+	<section>
+		<h2 class="mb-2 text-sm font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">
+			Schedules
+		</h2>
+		{#if data.schedules.length === 0}
+			<div class="rounded-lg border border-dashed border-gray-300 bg-white p-6 text-center text-sm text-gray-500 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-400">
+				No maintenance schedules on assets here. Set them up from each asset's page.
+			</div>
+		{:else}
+			<div class="overflow-hidden rounded-lg border border-gray-200 bg-white dark:border-gray-700 dark:bg-gray-800">
+				<table class="min-w-full divide-y divide-gray-200 dark:divide-gray-700">
+					<thead class="bg-gray-50 dark:bg-gray-700/40">
+						<tr>
+							<th class="px-4 py-2 text-left text-xs font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">Schedule</th>
+							<th class="px-4 py-2 text-left text-xs font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">Asset</th>
+							<th class="px-4 py-2 text-left text-xs font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">Interval</th>
+							<th class="px-4 py-2 text-left text-xs font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">Next due</th>
+							<th class="px-4 py-2 text-left text-xs font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">Status</th>
+						</tr>
+					</thead>
+					<tbody class="divide-y divide-gray-200 dark:divide-gray-700">
+						{#each [...overdue, ...upcoming, ...data.schedules.filter((s) => !s.active)] as s (s.id)}
+							{@const isOverdue = overdue.includes(s)}
+							<tr class="hover:bg-gray-50 dark:hover:bg-gray-700/30">
+								<td class="px-4 py-2 text-sm font-medium text-gray-900 dark:text-gray-100">{s.name}</td>
+								<td class="px-4 py-2 text-sm text-gray-500 dark:text-gray-400">
+									<a href="/assets/{s.assetId}" class="hover:text-primary-600 dark:hover:text-primary-400">{s.assetName}</a>
+								</td>
+								<td class="px-4 py-2 text-sm text-gray-500 dark:text-gray-400">every {s.intervalValue} {s.intervalUnit}</td>
+								<td class="px-4 py-2 text-sm text-gray-500 dark:text-gray-400">
+									{s.kind === 'time' ? fmtDate(s.nextDueAt) : `${s.nextDueUsage ?? '—'} ${s.intervalUnit}`}
+								</td>
+								<td class="px-4 py-2 text-xs">
+									{#if !s.active}
+										<span class="rounded bg-gray-100 px-1.5 py-0.5 text-gray-600 dark:bg-gray-700 dark:text-gray-300">paused</span>
+									{:else if isOverdue}
+										<span class="rounded bg-red-100 px-1.5 py-0.5 font-medium text-red-700 dark:bg-red-900/30 dark:text-red-300">overdue</span>
+									{:else}
+										<span class="rounded bg-emerald-100 px-1.5 py-0.5 text-emerald-700 dark:bg-emerald-900/30 dark:text-emerald-300">active</span>
+									{/if}
+								</td>
+							</tr>
+						{/each}
+					</tbody>
+				</table>
+			</div>
+		{/if}
+	</section>
+
+	<section>
+		<h2 class="mb-2 text-sm font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">
+			Recent events
+		</h2>
+		{#if data.events.length === 0}
+			<div class="rounded-lg border border-dashed border-gray-300 bg-white p-6 text-center text-sm text-gray-500 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-400">
+				No maintenance events recorded yet.
+			</div>
+		{:else}
+			<ul class="divide-y divide-gray-200 overflow-hidden rounded-lg border border-gray-200 bg-white dark:divide-gray-700 dark:border-gray-700 dark:bg-gray-800">
+				{#each data.events as e (e.id)}
+					<li class="flex items-start justify-between gap-3 px-4 py-3 text-sm">
+						<div>
+							<div class="font-medium text-gray-900 dark:text-gray-100">
+								{e.scheduleName ?? 'Ad-hoc service'} ·
+								<a href="/assets/{e.assetId}" class="text-primary-600 hover:underline dark:text-primary-400">{e.assetName}</a>
+							</div>
+							{#if e.notes}
+								<p class="mt-0.5 text-gray-500 dark:text-gray-400">{e.notes}</p>
+							{/if}
+						</div>
+						<div class="shrink-0 text-xs text-gray-500 dark:text-gray-400">{fmtDate(e.performedAt)}</div>
+					</li>
+				{/each}
+			</ul>
+		{/if}
+	</section>
+</div>

src/routes/(app)/properties/[id]/sub-properties/+page.server.ts

@@ -0,0 +1,27 @@
+import { error } from '@sveltejs/kit';
+import { and, asc, eq, isNull } from 'drizzle-orm';
+import { db } from '$lib/server/db/client';
+import { properties } from '$lib/server/db/schema/properties';
+import type { PageServerLoad } from './$types';
+
+export const load: PageServerLoad = async ({ locals, params }) => {
+	if (!locals.company) throw error(400, 'No active company');
+	const children = await db
+		.select({
+			id: properties.id,
+			name: properties.name,
+			kind: properties.kind,
+			city: properties.city,
+			countryCode: properties.countryCode
+		})
+		.from(properties)
+		.where(
+			and(
+				eq(properties.companyId, locals.company.id),
+				eq(properties.parentId, params.id),
+				isNull(properties.deletedAt)
+			)
+		)
+		.orderBy(asc(properties.name));
+	return { children };
+};

src/routes/(app)/properties/[id]/sub-properties/+page.svelte

@@ -0,0 +1,46 @@
+<script lang="ts">
+	import type { PageData } from './$types';
+	import type { LayoutData } from '../$types';
+
+	let { data }: { data: PageData & LayoutData } = $props();
+</script>
+
+<div class="space-y-4">
+	<div class="flex items-center justify-between">
+		<div>
+			<h2 class="text-lg font-semibold text-gray-900 dark:text-gray-100">Sub-properties</h2>
+			<p class="text-sm text-gray-500 dark:text-gray-400">
+				Properties whose parent is <strong>{data.property.name}</strong>. Use these for apartments
+				inside a building, sub-buildings on a campus, and so on.
+			</p>
+		</div>
+		<a
+			href="/properties/new?parent={data.property.id}"
+			class="rounded-md bg-primary-600 px-3 py-1.5 text-sm font-medium text-white shadow-sm hover:bg-primary-700"
+		>
+			+ New sub-property
+		</a>
+	</div>
+
+	{#if data.children.length === 0}
+		<div class="rounded-lg border border-dashed border-gray-300 bg-white p-8 text-center text-sm text-gray-500 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-400">
+			No sub-properties yet.
+		</div>
+	{:else}
+		<ul class="divide-y divide-gray-200 overflow-hidden rounded-lg border border-gray-200 bg-white dark:divide-gray-700 dark:border-gray-700 dark:bg-gray-800">
+			{#each data.children as c (c.id)}
+				<li>
+					<a href="/properties/{c.id}" class="flex items-center justify-between px-4 py-3 hover:bg-gray-50 dark:hover:bg-gray-700/40">
+						<div class="min-w-0">
+							<p class="truncate text-sm font-medium text-gray-900 dark:text-gray-100">{c.name}</p>
+							<p class="truncate text-xs text-gray-500 dark:text-gray-400">
+								{[c.kind, c.city, c.countryCode].filter(Boolean).join(' · ') || '—'}
+							</p>
+						</div>
+						<span class="text-xs text-gray-400 dark:text-gray-500">›</span>
+					</a>
+				</li>
+			{/each}
+		</ul>
+	{/if}
+</div>

src/routes/(app)/properties/[id]/todos/+page.server.ts

@@ -0,0 +1,14 @@
+import { error } from '@sveltejs/kit';
+import { listInstancesForProperties } from '$lib/server/services/checklists';
+import { getDescendantIds } from '$lib/server/services/properties';
+import type { PageServerLoad } from './$types';
+
+export const load: PageServerLoad = async ({ locals, params, url }) => {
+	if (!locals.company) throw error(401);
+	const includeDescendants = url.searchParams.get('descendants') === '1';
+	const propertyIds = includeDescendants
+		? await getDescendantIds(locals.company.id, params.id)
+		: [params.id];
+	const instances = await listInstancesForProperties(locals.company.id, propertyIds);
+	return { instances, includeDescendants, descendantCount: propertyIds.length };
+};

src/routes/(app)/properties/[id]/todos/+page.svelte

@@ -0,0 +1,86 @@
+<script lang="ts">
+	import type { PageData } from './$types';
+	import type { LayoutData } from '../$types';
+
+	let { data }: { data: PageData & LayoutData } = $props();
+
+	function fmtDate(d: Date | string | null | undefined): string {
+		if (!d) return '—';
+		const dt = typeof d === 'string' ? new Date(d) : d;
+		return Number.isNaN(dt.getTime()) ? '—' : dt.toISOString().slice(0, 10);
+	}
+
+	const open = $derived(data.instances.filter((i) => !i.completedAt));
+	const completed = $derived(data.instances.filter((i) => i.completedAt));
+</script>
+
+<div class="space-y-4">
+	{#if data.childCount > 0}
+		<div class="flex flex-wrap items-center justify-between gap-3 rounded-lg border border-gray-200 bg-white px-4 py-2.5 text-sm dark:border-gray-700 dark:bg-gray-800">
+			<div class="text-gray-700 dark:text-gray-300">
+				{#if data.includeDescendants}
+					<span class="font-medium">{data.property.name}</span> + sub-properties
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.descendantCount} total)</span>
+				{:else}
+					<span class="font-medium">{data.property.name}</span>
+					<span class="ml-1 text-xs text-gray-500 dark:text-gray-400">({data.childCount} sub-properties hidden)</span>
+				{/if}
+			</div>
+			<div role="tablist" class="inline-flex rounded-md border border-gray-200 bg-gray-50 p-0.5 text-xs font-medium dark:border-gray-700 dark:bg-gray-900">
+				{#each [{ v: '', l: 'This property' }, { v: '1', l: 'Include sub-properties' }] as opt}
+					{@const active = (data.includeDescendants ? '1' : '') === opt.v}
+					<a
+						role="tab"
+						href={opt.v ? '?descendants=1' : '?'}
+						aria-selected={active}
+						class="rounded px-2 py-1 transition {active
+							? 'bg-white text-gray-900 shadow-sm dark:bg-gray-700 dark:text-gray-100'
+							: 'text-gray-600 hover:text-gray-900 dark:text-gray-400 dark:hover:text-gray-100'}"
+					>
+						{opt.l}
+					</a>
+				{/each}
+			</div>
+		</div>
+	{/if}
+
+	<section>
+		<h2 class="mb-2 text-sm font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">
+			Open ({open.length})
+		</h2>
+		{#if open.length === 0}
+			<div class="rounded-lg border border-dashed border-gray-300 bg-white p-6 text-center text-sm text-gray-500 dark:border-gray-700 dark:bg-gray-800 dark:text-gray-400">
+				No open checklists for this property.
+			</div>
+		{:else}
+			<ul class="divide-y divide-gray-200 overflow-hidden rounded-lg border border-gray-200 bg-white dark:divide-gray-700 dark:border-gray-700 dark:bg-gray-800">
+				{#each open as i (i.id)}
+					<li class="px-4 py-3 text-sm">
+						<a href="/checklists/{i.id}" class="font-medium text-gray-900 hover:text-primary-600 dark:text-gray-100 dark:hover:text-primary-400">
+							{i.title ?? 'Checklist'}
+						</a>
+						<div class="mt-0.5 text-xs text-gray-500 dark:text-gray-400">created {fmtDate(i.createdAt)}</div>
+					</li>
+				{/each}
+			</ul>
+		{/if}
+	</section>
+
+	{#if completed.length > 0}
+		<section>
+			<h2 class="mb-2 text-sm font-semibold uppercase tracking-wider text-gray-500 dark:text-gray-400">
+				Completed ({completed.length})
+			</h2>
+			<ul class="divide-y divide-gray-200 overflow-hidden rounded-lg border border-gray-200 bg-white dark:divide-gray-700 dark:border-gray-700 dark:bg-gray-800">
+				{#each completed as i (i.id)}
+					<li class="px-4 py-3 text-sm">
+						<a href="/checklists/{i.id}" class="text-gray-700 hover:text-primary-600 dark:text-gray-300 dark:hover:text-primary-400">
+							{i.title ?? 'Checklist'}
+						</a>
+						<div class="mt-0.5 text-xs text-gray-500 dark:text-gray-400">completed {fmtDate(i.completedAt)}</div>
+					</li>
+				{/each}
+			</ul>
+		</section>
+	{/if}
+</div>

src/routes/(app)/properties/new/+page.server.ts

@@ -1,11 +1,15 @@
-import { fail, redirect, error } from '@sveltejs/kit';
+import { error, fail, redirect } from '@sveltejs/kit';
+import { and, eq, isNull } from 'drizzle-orm';
 import { z } from 'zod';
+import { db } from '$lib/server/db/client';
+import { properties } from '$lib/server/db/schema/properties';
 import { createProperty } from '$lib/server/services/properties';
-import type { Actions } from './$types';
+import type { Actions, PageServerLoad } from './$types';
 
 const PropertySchema = z.object({
 	name: z.string().trim().min(1, 'Name is required').max(255),
 	kind: z.string().trim().max(64).optional().or(z.literal('')),
+	parentId: z.string().uuid().optional().or(z.literal('')),
 	addressLine1: z.string().trim().max(255).optional().or(z.literal('')),
 	addressLine2: z.string().trim().max(255).optional().or(z.literal('')),
 	city: z.string().trim().max(128).optional().or(z.literal('')),
@@ -19,6 +23,17 @@ function emptyToNull(s: string | undefined): string | null {
 	return !s ? null : s;
 }
 
+export const load: PageServerLoad = async ({ locals, url }) => {
+	if (!locals.company) throw error(400, 'No active company');
+	const eligibleParents = await db
+		.select({ id: properties.id, name: properties.name })
+		.from(properties)
+		.where(and(eq(properties.companyId, locals.company.id), isNull(properties.deletedAt)))
+		.orderBy(properties.name);
+	const preselectParentId = url.searchParams.get('parent') ?? '';
+	return { eligibleParents, preselectParentId };
+};
+
 export const actions: Actions = {
 	default: async ({ request, locals }) => {
 		if (!locals.user || !locals.company) throw error(401, 'Not authenticated');
@@ -33,19 +48,27 @@ export const actions: Actions = {
 			});
 		}
 		const v = parsed.data;
-		const { id } = await createProperty({
+		try {
-			companyId: locals.company.id,
+			const { id } = await createProperty({
-			createdBy: locals.user.id,
+				companyId: locals.company.id,
-			name: v.name,
+				createdBy: locals.user.id,
-			kind: emptyToNull(v.kind),
+				name: v.name,
-			addressLine1: emptyToNull(v.addressLine1),
+				kind: emptyToNull(v.kind),
-			addressLine2: emptyToNull(v.addressLine2),
+				parentId: v.parentId ? v.parentId : null,
-			city: emptyToNull(v.city),
+				addressLine1: emptyToNull(v.addressLine1),
-			region: emptyToNull(v.region),
+				addressLine2: emptyToNull(v.addressLine2),
-			postalCode: emptyToNull(v.postalCode),
+				city: emptyToNull(v.city),
-			countryCode: emptyToNull(v.countryCode),
+				region: emptyToNull(v.region),
-			notes: emptyToNull(v.notes)
+				postalCode: emptyToNull(v.postalCode),
-		});
+				countryCode: emptyToNull(v.countryCode),
-		throw redirect(303, `/properties/${id}`);
+				notes: emptyToNull(v.notes)
+			});
+			throw redirect(303, `/properties/${id}`);
+		} catch (e) {
+			// SvelteKit redirects throw; let them bubble.
+			const { isRedirect, isHttpError } = await import('@sveltejs/kit');
+			if (isRedirect(e) || isHttpError(e)) throw e;
+			return fail(400, { error: (e as Error).message, values: raw });
+		}
 	}
 };

src/routes/(app)/properties/new/+page.svelte

@@ -1,11 +1,15 @@
 <script lang="ts">
 	import { enhance } from '$app/forms';
-	import type { ActionData } from './$types';
+	import type { ActionData, PageData } from './$types';
 
-	let { form }: { form: ActionData } = $props();
+	let { data, form }: { data: PageData; form: ActionData } = $props();
 	let submitting = $state(false);
 
 	const v = $derived((form?.values ?? {}) as Record<string, string>);
+	const selectedParent = $derived(v.parentId ?? data.preselectParentId ?? '');
+	const parentName = $derived(
+		data.eligibleParents.find((p) => p.id === selectedParent)?.name ?? null
+	);
 </script>
 
 <div class="mx-auto max-w-2xl space-y-6">
@@ -13,6 +17,11 @@
 		<h1 class="text-2xl font-semibold text-gray-900 dark:text-gray-100">New property</h1>
 		<p class="mt-1 text-sm text-gray-500 dark:text-gray-400">
 			A property is a place where assets live (a warehouse, an office, a datacenter, a site).
+			{#if parentName}
+				<span class="ml-1 text-gray-700 dark:text-gray-300">
+					Creating as a sub-property under <strong>{parentName}</strong>.
+				</span>
+			{/if}
 		</p>
 	</div>
 
@@ -42,6 +51,17 @@
 				class="mt-1 block w-full rounded-md border border-gray-300 bg-white px-3 py-2 text-sm shadow-sm placeholder:text-gray-400 focus:border-primary-500 focus:outline-none focus:ring-1 focus:ring-primary-500 dark:border-gray-600 dark:bg-gray-900 dark:text-gray-100" />
 		</div>
 
+		<div>
+			<label for="parentId" class="block text-sm font-medium text-gray-700 dark:text-gray-300">Parent property</label>
+			<select id="parentId" name="parentId"
+				class="mt-1 block w-full rounded-md border border-gray-300 bg-white px-3 py-2 text-sm shadow-sm focus:border-primary-500 focus:outline-none focus:ring-1 focus:ring-primary-500 dark:border-gray-600 dark:bg-gray-900 dark:text-gray-100">
+				<option value="">— Top level (no parent) —</option>
+				{#each data.eligibleParents as opt (opt.id)}
+					<option value={opt.id} selected={opt.id === selectedParent}>{opt.name}</option>
+				{/each}
+			</select>
+		</div>
+
 		<div class="grid gap-4 sm:grid-cols-2">
 			<div class="sm:col-span-2">
 				<label for="addressLine1" class="block text-sm font-medium text-gray-700 dark:text-gray-300">Address line 1</label>