diff --git a/src/Controller/Admin/Resource/CreateController.php b/src/Controller/Admin/Resource/CreateController.php
new file mode 100644
index 0000000..f183b88
--- /dev/null
+++ b/src/Controller/Admin/Resource/CreateController.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\Resource;
+
+use App\Entity\Resource;
+use App\Enum\ResourceType;
+use App\Form\Admin\ResourceFormType;
+use App\Htmx\HxRedirectResponse;
+use App\Security\Role;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+#[IsGranted(Role::ADMIN)]
+final class CreateController extends AbstractController
+{
+    public function __construct(
+        private readonly EntityManagerInterface $em,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    /**
+     * GET renders the modal, POST saves it. An invalid submit re-renders the modal as a 422, which
+     * htmx swaps in place; a valid one navigates back to the list.
+     */
+    #[Route('/admin/resources/new/{type}', name: 'app_admin_resource_new', methods: ['GET', 'POST'])]
+    public function index(Request $request, ResourceType $type): Response
+    {
+        $resource = new Resource($type, '');
+        $form = $this->createForm(ResourceFormType::class, $resource, [
+            'action' => $this->generateUrl('app_admin_resource_new', ['type' => $type->value]),
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            $this->em->persist($resource);
+            $this->em->flush();
+
+            $this->logger->info('Admin created a resource.', [
+                'admin' => $this->getUser()?->getUserIdentifier(),
+                'resource_id' => $resource->getId(),
+                'type' => $type->value,
+                'label' => $resource->getLabel(),
+            ]);
+            $this->addFlash('success', \sprintf('%s angelegt.', $resource->getLabel()));
+
+            return new HxRedirectResponse($this->generateUrl('app_admin_resource'));
+        }
+
+        return $this->render('admin/_modal_resource.html.twig', [
+            'form' => $form,
+            'resource' => $resource,
+        ]);
+    }
+}
diff --git a/src/Controller/Admin/Resource/EditController.php b/src/Controller/Admin/Resource/EditController.php
new file mode 100644
index 0000000..b81e425
--- /dev/null
+++ b/src/Controller/Admin/Resource/EditController.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\Resource;
+
+use App\Entity\Resource;
+use App\Form\Admin\ResourceFormType;
+use App\Htmx\HxRedirectResponse;
+use App\Repository\BookingRepository;
+use App\Security\Role;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/**
+ * Renaming, moving to another room, and retiring or reactivating.
+ *
+ * Retiring is a checkbox here rather than a confirmation modal of its own: it deletes nothing and
+ * is undone by ticking the box again. What it does leave behind -- bookings that still point at
+ * the resource -- is named in the flash, so the administrator can release them from
+ * /admin/bookings if they should not stand.
+ */
+#[IsGranted(Role::ADMIN)]
+final class EditController extends AbstractController
+{
+    public function __construct(
+        private readonly EntityManagerInterface $em,
+        private readonly BookingRepository $bookings,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/resources/{id}/edit', name: 'app_admin_resource_edit', methods: ['GET', 'POST'])]
+    public function index(Request $request, Resource $resource): Response
+    {
+        $wasActive = $resource->isActive();
+
+        $form = $this->createForm(ResourceFormType::class, $resource, [
+            'action' => $this->generateUrl('app_admin_resource_edit', ['id' => $resource->getId()]),
+            'with_active' => true,
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            $this->em->flush();
+
+            $this->logger->info('Admin edited a resource.', [
+                'admin' => $this->getUser()?->getUserIdentifier(),
+                'resource_id' => $resource->getId(),
+                'label' => $resource->getLabel(),
+                'group' => $resource->getGroup()?->getLabel(),
+                'active' => $resource->isActive(),
+            ]);
+
+            $remaining = $wasActive && !$resource->isActive()
+                ? $this->bookings->countFromDate($resource, new \DateTimeImmutable('today'))
+                : 0;
+
+            if ($remaining > 0) {
+                $this->addFlash('warning', \sprintf(
+                    '%s ist nicht mehr buchbar. %d bestehende Buchungen ab heute bleiben erhalten.',
+                    $resource->getLabel(),
+                    $remaining,
+                ));
+            } else {
+                $this->addFlash('success', \sprintf('%s gespeichert.', $resource->getLabel()));
+            }
+
+            return new HxRedirectResponse($this->generateUrl('app_admin_resource'));
+        }
+
+        return $this->render('admin/_modal_resource.html.twig', [
+            'form' => $form,
+            'resource' => $resource,
+        ]);
+    }
+}
diff --git a/src/Controller/Admin/Resource/IndexController.php b/src/Controller/Admin/Resource/IndexController.php
new file mode 100644
index 0000000..06c5d82
--- /dev/null
+++ b/src/Controller/Admin/Resource/IndexController.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\Resource;
+
+use App\Enum\ResourceType;
+use App\Repository\ResourceGroupRepository;
+use App\Repository\ResourceRepository;
+use App\Security\Role;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/**
+ * Everything that can be booked, per type and room, retired resources included.
+ *
+ * Creating and editing happen in modals that navigate back here once saved. Nothing is ever
+ * deleted except an empty room: a resource with history is retired instead, so its bookings keep
+ * resolving.
+ */
+#[IsGranted(Role::ADMIN)]
+final class IndexController extends AbstractController
+{
+    public function __construct(
+        private readonly ResourceRepository $resources,
+        private readonly ResourceGroupRepository $groups,
+    ) {
+    }
+
+    #[Route('/admin/resources', name: 'app_admin_resource', methods: ['GET'])]
+    public function index(): Response
+    {
+        $sections = [];
+
+        foreach (ResourceType::cases() as $type) {
+            $byGroup = [];
+            $ungrouped = [];
+
+            foreach ($this->resources->findAllByType($type) as $resource) {
+                if (null === $resource->getGroup()) {
+                    $ungrouped[] = $resource;
+                } else {
+                    $byGroup[$resource->getGroup()->getId()][] = $resource;
+                }
+            }
+
+            $sections[] = [
+                'type' => $type,
+                // Every group, empty ones too -- an empty room is the only thing that can be
+                // deleted, so it has to be visible.
+                'groups' => array_map(
+                    static fn ($group): array => ['group' => $group, 'resources' => $byGroup[$group->getId()] ?? []],
+                    $this->groups->findByType($type),
+                ),
+                'ungrouped' => $ungrouped,
+            ];
+        }
+
+        return $this->render('admin/resources.html.twig', [
+            'sections' => $sections,
+        ]);
+    }
+}
diff --git a/src/Controller/Admin/ResourceGroup/CreateController.php b/src/Controller/Admin/ResourceGroup/CreateController.php
new file mode 100644
index 0000000..c15893b
--- /dev/null
+++ b/src/Controller/Admin/ResourceGroup/CreateController.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\ResourceGroup;
+
+use App\Entity\ResourceGroup;
+use App\Enum\ResourceType;
+use App\Form\Admin\ResourceGroupFormType;
+use App\Htmx\HxRedirectResponse;
+use App\Repository\ResourceGroupRepository;
+use App\Security\Role;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+#[IsGranted(Role::ADMIN)]
+final class CreateController extends AbstractController
+{
+    public function __construct(
+        private readonly EntityManagerInterface $em,
+        private readonly ResourceGroupRepository $groups,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/resource-groups/new/{type}', name: 'app_admin_resource_group_new', methods: ['GET', 'POST'])]
+    public function index(Request $request, ResourceType $type): Response
+    {
+        // Prefilled to come after the existing ones, which is where a new room usually belongs.
+        $existing = $this->groups->findByType($type);
+        $position = [] === $existing ? 0 : max(array_map(static fn (ResourceGroup $group): int => $group->getPosition(), $existing)) + 1;
+
+        $group = new ResourceGroup($type, '', $position);
+        $form = $this->createForm(ResourceGroupFormType::class, $group, [
+            'action' => $this->generateUrl('app_admin_resource_group_new', ['type' => $type->value]),
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            $this->em->persist($group);
+            $this->em->flush();
+
+            $this->logger->info('Admin created a resource group.', [
+                'admin' => $this->getUser()?->getUserIdentifier(),
+                'group_id' => $group->getId(),
+                'type' => $type->value,
+                'label' => $group->getLabel(),
+            ]);
+            $this->addFlash('success', \sprintf('%s angelegt.', $group->getLabel()));
+
+            return new HxRedirectResponse($this->generateUrl('app_admin_resource'));
+        }
+
+        return $this->render('admin/_modal_resource_group.html.twig', [
+            'form' => $form,
+            'group' => $group,
+        ]);
+    }
+}
diff --git a/src/Controller/Admin/ResourceGroup/DeleteController.php b/src/Controller/Admin/ResourceGroup/DeleteController.php
new file mode 100644
index 0000000..5d15f0a
--- /dev/null
+++ b/src/Controller/Admin/ResourceGroup/DeleteController.php
@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\ResourceGroup;
+
+use App\Controller\Traits\ConfirmedActionTrait;
+use App\Entity\ResourceGroup;
+use App\Htmx\HxRedirectResponse;
+use App\Repository\ResourceRepository;
+use App\Security\Role;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/**
+ * Only an empty room can be deleted -- retired resources count, since they still sit in it.
+ *
+ * The foreign key would allow more (ON DELETE SET NULL), but silently turning a room's desks into
+ * ungrouped ones is never what deleting a room means. Move them first.
+ */
+#[IsGranted(Role::ADMIN)]
+final class DeleteController extends AbstractController
+{
+    use ConfirmedActionTrait;
+
+    public function __construct(
+        private readonly EntityManagerInterface $em,
+        private readonly ResourceRepository $resources,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/resource-groups/{id}/delete', name: 'app_admin_resource_group_delete', methods: ['GET', 'POST'])]
+    public function index(Request $request, ResourceGroup $group): Response
+    {
+        if ($this->resources->count(['group' => $group]) > 0) {
+            throw $this->createAccessDeniedException('Only an empty resource group can be deleted.');
+        }
+
+        if (!$request->isMethod(Request::METHOD_POST)) {
+            return $this->render('admin/_modal_resource_group_delete.html.twig', [
+                'group' => $group,
+                'csrf_token_id' => 'delete-resource-group-'.$group->getId(),
+            ]);
+        }
+
+        $this->denyUnlessCsrfValid($request, 'delete-resource-group-'.$group->getId());
+
+        $this->logger->info('Admin deleted a resource group.', [
+            'admin' => $this->getUser()?->getUserIdentifier(),
+            'group_id' => $group->getId(),
+            'label' => $group->getLabel(),
+        ]);
+
+        $label = $group->getLabel();
+        $this->em->remove($group);
+        $this->em->flush();
+
+        $this->addFlash('success', \sprintf('%s gelöscht.', $label));
+
+        return new HxRedirectResponse($this->generateUrl('app_admin_resource'));
+    }
+}
diff --git a/src/Controller/Admin/ResourceGroup/EditController.php b/src/Controller/Admin/ResourceGroup/EditController.php
new file mode 100644
index 0000000..4b5d709
--- /dev/null
+++ b/src/Controller/Admin/ResourceGroup/EditController.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\ResourceGroup;
+
+use App\Entity\ResourceGroup;
+use App\Form\Admin\ResourceGroupFormType;
+use App\Htmx\HxRedirectResponse;
+use App\Security\Role;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+#[IsGranted(Role::ADMIN)]
+final class EditController extends AbstractController
+{
+    public function __construct(
+        private readonly EntityManagerInterface $em,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/resource-groups/{id}/edit', name: 'app_admin_resource_group_edit', methods: ['GET', 'POST'])]
+    public function index(Request $request, ResourceGroup $group): Response
+    {
+        $form = $this->createForm(ResourceGroupFormType::class, $group, [
+            'action' => $this->generateUrl('app_admin_resource_group_edit', ['id' => $group->getId()]),
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            $this->em->flush();
+
+            $this->logger->info('Admin edited a resource group.', [
+                'admin' => $this->getUser()?->getUserIdentifier(),
+                'group_id' => $group->getId(),
+                'label' => $group->getLabel(),
+                'position' => $group->getPosition(),
+            ]);
+            $this->addFlash('success', \sprintf('%s gespeichert.', $group->getLabel()));
+
+            return new HxRedirectResponse($this->generateUrl('app_admin_resource'));
+        }
+
+        return $this->render('admin/_modal_resource_group.html.twig', [
+            'form' => $form,
+            'group' => $group,
+        ]);
+    }
+}
diff --git a/src/Entity/Resource.php b/src/Entity/Resource.php
index a67ae5c..275d41a 100644
--- a/src/Entity/Resource.php
+++ b/src/Entity/Resource.php
@@ -7,6 +7,7 @@ namespace App\Entity;
 use App\Enum\ResourceType;
 use App\Repository\ResourceRepository;
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 use Symfony\Component\Validator\Constraints as Assert;
 
 /**
@@ -14,6 +15,7 @@ use Symfony\Component\Validator\Constraints as Assert;
  */
 #[ORM\Entity(repositoryClass: ResourceRepository::class)]
 #[ORM\UniqueConstraint(name: 'uniq_resource_label', columns: ['type', 'label'])]
+#[UniqueEntity(fields: ['type', 'label'], message: 'Diese Bezeichnung ist bereits vergeben.', errorPath: 'label')]
 class Resource
 {
     #[ORM\Id]
@@ -26,6 +28,7 @@ class Resource
 
     #[ORM\Column(length: 50)]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 50)]
     private string $label;
 
     /**
diff --git a/src/Entity/ResourceGroup.php b/src/Entity/ResourceGroup.php
index 9dcaf3a..a5483a6 100644
--- a/src/Entity/ResourceGroup.php
+++ b/src/Entity/ResourceGroup.php
@@ -7,14 +7,14 @@ namespace App\Entity;
 use App\Enum\ResourceType;
 use App\Repository\ResourceGroupRepository;
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 use Symfony\Component\Validator\Constraints as Assert;
 
 /**
  * Where a bookable thing physically is: a room of the office, an area of the car park.
  *
  * A group belongs to exactly one ResourceType, because "Raum Nord" means nothing for parking.
- * It is a description of the building, so it is configuration seeded alongside the resources
- * rather than something a user creates.
+ * It is a description of the building, maintained by an administrator under /admin/resources.
  *
  * Note there is deliberately no method named `group`, `label` or `position` other than the plain
  * accessors: Twig resolves `x.label` to a method of that literal name before trying getLabel(),
@@ -22,6 +22,7 @@ use Symfony\Component\Validator\Constraints as Assert;
  */
 #[ORM\Entity(repositoryClass: ResourceGroupRepository::class)]
 #[ORM\UniqueConstraint(name: 'uniq_resource_group_label', columns: ['type', 'label'])]
+#[UniqueEntity(fields: ['type', 'label'], message: 'Diese Bezeichnung ist bereits vergeben.', errorPath: 'label')]
 class ResourceGroup
 {
     #[ORM\Id]
@@ -34,6 +35,7 @@ class ResourceGroup
 
     #[ORM\Column(length: 50)]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 50)]
     private string $label;
 
     /** Draw and list order within the type. */
diff --git a/src/Enum/ResourceType.php b/src/Enum/ResourceType.php
index 1c51d04..8a4fbb0 100644
--- a/src/Enum/ResourceType.php
+++ b/src/Enum/ResourceType.php
@@ -8,8 +8,8 @@ namespace App\Enum;
  * The kinds of thing that can be booked.
  *
  * **This enum is the extension point.** The dashboard builds one tile per case, the board route
- * accepts one backing value per case, and the floor plan renders every kind the same way.
- * Adding a third bookable kind is therefore: a case here and rows in `app:seed`.
+ * accepts one backing value per case, and the floor plan and the admin screen render every kind
+ * the same way. Adding a third bookable kind is therefore: a case here.
  * Nothing else needs editing — in particular no template lists the kinds by hand.
  *
  * The backing value is both what is persisted in `resource.type` and what appears in a URL, so
@@ -45,6 +45,17 @@ enum ResourceType: string
         };
     }
 
+    /**
+     * What a ResourceGroup of this kind is called: an office has rooms, a car park has areas.
+     */
+    public function groupLabel(): string
+    {
+        return match ($this) {
+            self::DESK => 'Raum',
+            self::PARKING => 'Bereich',
+        };
+    }
+
     public function icon(): string
     {
         return match ($this) {
diff --git a/src/Form/Admin/ResourceFormType.php b/src/Form/Admin/ResourceFormType.php
new file mode 100644
index 0000000..b2ec15f
--- /dev/null
+++ b/src/Form/Admin/ResourceFormType.php
@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Admin;
+
+use App\Entity\Resource;
+use App\Entity\ResourceGroup;
+use App\Enum\ResourceType;
+use Doctrine\ORM\EntityRepository;
+use Symfony\Bridge\Doctrine\Form\Type\EntityType;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
+use Symfony\Component\Form\Extension\Core\Type\TextType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * A desk or parking spot. The type is not a field: it is fixed by the route that creates the
+ * resource and never changes afterwards, which is what lets the group choices be limited to it.
+ */
+final class ResourceFormType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $resource = $builder->getData();
+        \assert($resource instanceof Resource);
+        $type = $resource->getType();
+
+        $builder
+            ->add('label', TextType::class, [
+                'label' => 'Bezeichnung',
+            ])
+            ->add('group', EntityType::class, [
+                'label' => $type->groupLabel(),
+                'class' => ResourceGroup::class,
+                'required' => false,
+                'placeholder' => 'Ohne '.$type->groupLabel(),
+                'choice_label' => 'label',
+                // A group of another type would be tampering, and the choice list rejects it.
+                'query_builder' => static fn (EntityRepository $repository) => $repository
+                    ->createQueryBuilder('g')
+                    ->andWhere('g.type = :type')
+                    ->setParameter('type', $type)
+                    ->orderBy('g.position', 'ASC')
+                    ->addOrderBy('g.label', 'ASC'),
+            ]);
+
+        // Only on edit: a resource is created bookable, and retiring it is a later decision.
+        if ($options['with_active']) {
+            $builder->add('active', CheckboxType::class, [
+                'label' => 'Buchbar',
+                'help' => 'Nicht buchbare Plätze erscheinen nicht mehr im Plan. Bestehende Buchungen bleiben erhalten.',
+                'required' => false,
+            ]);
+        }
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => Resource::class,
+            'with_active' => false,
+        ]);
+        $resolver->setAllowedTypes('with_active', 'bool');
+    }
+}
diff --git a/src/Form/Admin/ResourceGroupFormType.php b/src/Form/Admin/ResourceGroupFormType.php
new file mode 100644
index 0000000..c75beee
--- /dev/null
+++ b/src/Form/Admin/ResourceGroupFormType.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Admin;
+
+use App\Entity\ResourceGroup;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\IntegerType;
+use Symfony\Component\Form\Extension\Core\Type\TextType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * A room or area. Like a resource, its type is fixed by the route that creates it.
+ */
+final class ResourceGroupFormType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('label', TextType::class, [
+                'label' => 'Bezeichnung',
+            ])
+            ->add('position', IntegerType::class, [
+                'label' => 'Reihenfolge',
+                'help' => 'Kleinere Zahlen stehen im Plan weiter oben.',
+                // The setter takes an int, so a cleared field must not reach it as null.
+                'empty_data' => '0',
+            ]);
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => ResourceGroup::class,
+        ]);
+    }
+}
diff --git a/src/Repository/BookingRepository.php b/src/Repository/BookingRepository.php
index 4661e71..a25fdc9 100644
--- a/src/Repository/BookingRepository.php
+++ b/src/Repository/BookingRepository.php
@@ -205,6 +205,21 @@ class BookingRepository extends ServiceEntityRepository
         return $qb->getQuery()->getResult();
     }
 
+    /**
+     * Bookings from a day onwards, so retiring a resource can say what it leaves behind.
+     */
+    public function countFromDate(Resource $resource, \DateTimeImmutable $from): int
+    {
+        return (int) $this->createQueryBuilder('b')
+            ->select('COUNT(b.id)')
+            ->andWhere('b.resource = :resource')
+            ->andWhere('b.date >= :from')
+            ->setParameter('resource', $resource)
+            ->setParameter('from', $from->setTime(0, 0))
+            ->getQuery()
+            ->getSingleScalarResult();
+    }
+
     /**
      * The occurrences an "end this series" would remove.
      *
diff --git a/src/Repository/ResourceRepository.php b/src/Repository/ResourceRepository.php
index a938129..b31f768 100644
--- a/src/Repository/ResourceRepository.php
+++ b/src/Repository/ResourceRepository.php
@@ -42,6 +42,23 @@ class ResourceRepository extends ServiceEntityRepository
             ->getResult();
     }
 
+    /**
+     * Retired ones included, for the admin screen -- which is where they are reactivated.
+     *
+     * @return list<Resource>
+     */
+    public function findAllByType(ResourceType $type): array
+    {
+        return $this->createQueryBuilder('r')
+            ->leftJoin('r.group', 'g')
+            ->addSelect('g')
+            ->andWhere('r.type = :type')
+            ->setParameter('type', $type)
+            ->orderBy('r.label', 'ASC')
+            ->getQuery()
+            ->getResult();
+    }
+
     /**
      * @return list<Resource>
      */
diff --git a/templates/admin/_modal_resource.html.twig b/templates/admin/_modal_resource.html.twig
new file mode 100644
index 0000000..1c8a46f
--- /dev/null
+++ b/templates/admin/_modal_resource.html.twig
@@ -0,0 +1,41 @@
+{#
+    Creating and editing a desk or parking spot. Same double duty as the booking modal: the form
+    targets the modal itself, so an invalid submit (422) replaces it with the errors showing, and a
+    valid one answers with HX-Redirect back to the list.
+#}
+{% extends 'htmx_modal.html.twig' %}
+
+{% block title %}
+    {%- if resource.id -%}
+        {{ resource.label }} bearbeiten
+    {%- else -%}
+        {{ resource.type.label }} hinzufügen
+    {%- endif -%}
+{% endblock %}
+
+{% block content %}
+    {{ form_start(form, { attr: {
+        'hx-post': form.vars.action,
+        'hx-target': '#htmx-modal',
+        'hx-swap': 'outerHTML',
+    } }) }}
+        {{ form_errors(form) }}
+
+        <div class="space-y-4">
+            {{ form_row(form.label) }}
+            {{ form_row(form.group) }}
+            {% if form.active is defined %}
+                {{ form_row(form.active) }}
+            {% endif %}
+        </div>
+
+        <div class="flex justify-end gap-2 pt-6">
+            <button type="button" class="button button--neutral" {{ stimulus_action('modal', 'close') }}>
+                Abbrechen
+            </button>
+            <button type="submit" class="button button--primary">
+                Speichern
+            </button>
+        </div>
+    {{ form_end(form) }}
+{% endblock %}
diff --git a/templates/admin/_modal_resource_group.html.twig b/templates/admin/_modal_resource_group.html.twig
new file mode 100644
index 0000000..01c1262
--- /dev/null
+++ b/templates/admin/_modal_resource_group.html.twig
@@ -0,0 +1,34 @@
+{# Creating and editing a room or area. See admin/_modal_resource.html.twig for how it closes. #}
+{% extends 'htmx_modal.html.twig' %}
+
+{% block title %}
+    {%- if group.id -%}
+        {{ group.label }} bearbeiten
+    {%- else -%}
+        {{ group.type.groupLabel }} hinzufügen
+    {%- endif -%}
+{% endblock %}
+
+{% block content %}
+    {{ form_start(form, { attr: {
+        'hx-post': form.vars.action,
+        'hx-target': '#htmx-modal',
+        'hx-swap': 'outerHTML',
+    } }) }}
+        {{ form_errors(form) }}
+
+        <div class="space-y-4">
+            {{ form_row(form.label) }}
+            {{ form_row(form.position) }}
+        </div>
+
+        <div class="flex justify-end gap-2 pt-6">
+            <button type="button" class="button button--neutral" {{ stimulus_action('modal', 'close') }}>
+                Abbrechen
+            </button>
+            <button type="submit" class="button button--primary">
+                Speichern
+            </button>
+        </div>
+    {{ form_end(form) }}
+{% endblock %}
diff --git a/templates/admin/_modal_resource_group_delete.html.twig b/templates/admin/_modal_resource_group_delete.html.twig
new file mode 100644
index 0000000..5750fb1
--- /dev/null
+++ b/templates/admin/_modal_resource_group_delete.html.twig
@@ -0,0 +1,11 @@
+{% extends 'htmx_confirmation_modal.html.twig' %}
+
+{% block title %}{{ group.type.groupLabel }} löschen?{% endblock %}
+
+{% block content %}
+    <p>
+        {{ group.type.groupLabel }} <em>{{ group.label }}</em> wird gelöscht.
+    </p>
+{% endblock %}
+
+{% block button_confirm %}Löschen{% endblock %}
diff --git a/templates/admin/resources.html.twig b/templates/admin/resources.html.twig
new file mode 100644
index 0000000..14733c1
--- /dev/null
+++ b/templates/admin/resources.html.twig
@@ -0,0 +1,86 @@
+{#
+    Everything bookable, per type and room. Every write opens a modal via htmx and navigates back
+    here once saved -- the same shape as the sibling apps' admin lists.
+
+    Retired resources stay listed, muted, because this is the only place they can be reactivated.
+    Only an empty room offers "Löschen"; DeleteController refuses the rest regardless.
+#}
+{% extends 'layout.html.twig' %}
+
+{% block title %}Plätze & Räume · ephub{% endblock %}
+
+{% macro opener(url, label, variant = 'neutral') %}
+    <button type="button" class="button button--small button--{{ variant }}"
+            hx-get="{{ url }}"
+            hx-target="body"
+            hx-swap="beforeend">{{ label }}</button>
+{% endmacro %}
+
+{% macro resource_list(resources) %}
+    {% if resources is empty %}
+        <p class="py-3 text-sm text-gray-500">Noch nichts angelegt.</p>
+    {% else %}
+        <ul class="divide-y divide-gray-200 border-y border-gray-200">
+            {% for resource in resources %}
+                <li class="flex items-center justify-between gap-4 py-2" data-resource>
+                    <span class="{{ resource.active ? '' : 'text-gray-400' }}">
+                        {{ resource.label }}
+                        {% if not resource.active %}
+                            <span class="badge bg-gray-100 text-gray-600 ml-1">nicht buchbar</span>
+                        {% endif %}
+                    </span>
+                    {{ _self.opener(path('app_admin_resource_edit', { id: resource.id }), 'Bearbeiten') }}
+                </li>
+            {% endfor %}
+        </ul>
+    {% endif %}
+{% endmacro %}
+
+{% block content %}
+    <a class="text-sm text-gray-500 hover:text-gray-900" href="{{ path('app_dashboard') }}">← Übersicht</a>
+
+    <h1 class="pt-2">Plätze & Räume</h1>
+    <p class="subline">Was gebucht werden kann und wo es steht.</p>
+
+    {% for section in sections %}
+        {% set type = section.type %}
+
+        <section class="pt-8" data-type="{{ type.value }}">
+            <div class="flex flex-wrap items-baseline justify-between gap-2">
+                <h2>{{ type.plural }}</h2>
+                <div class="flex gap-2">
+                    {{ _self.opener(path('app_admin_resource_group_new', { type: type.value }), type.groupLabel ~ ' hinzufügen') }}
+                    {{ _self.opener(path('app_admin_resource_new', { type: type.value }), type.label ~ ' hinzufügen', 'primary') }}
+                </div>
+            </div>
+
+            {% for entry in section.groups %}
+                <div class="pt-4" data-group>
+                    <div class="flex flex-wrap items-center justify-between gap-2 pb-1">
+                        <h3 class="!mb-0 text-base md:text-base">
+                            {{ entry.group.label }}
+                        </h3>
+                        <div class="flex gap-2">
+                            {{ _self.opener(path('app_admin_resource_group_edit', { id: entry.group.id }), 'Bearbeiten') }}
+                            {% if entry.resources is empty %}
+                                {{ _self.opener(path('app_admin_resource_group_delete', { id: entry.group.id }), 'Löschen') }}
+                            {% endif %}
+                        </div>
+                    </div>
+                    {{ _self.resource_list(entry.resources) }}
+                </div>
+            {% endfor %}
+
+            {# Only when there is something to show, or when there are no groups at all -- then this
+               is simply the list, as for the car park. #}
+            {% if section.ungrouped is not empty or section.groups is empty %}
+                <div class="pt-4" data-group>
+                    {% if section.groups is not empty %}
+                        <h3 class="!mb-0 pb-1 text-base md:text-base">Ohne {{ type.groupLabel }}</h3>
+                    {% endif %}
+                    {{ _self.resource_list(section.ungrouped) }}
+                </div>
+            {% endif %}
+        </section>
+    {% endfor %}
+{% endblock %}
diff --git a/templates/dashboard/index.html.twig b/templates/dashboard/index.html.twig
index 745cfe3..2b05905 100644
--- a/templates/dashboard/index.html.twig
+++ b/templates/dashboard/index.html.twig
@@ -63,6 +63,17 @@
                     Buchungen aller Mitarbeitenden einsehen und ggf. freigeben.
                 </p>
             </a>
+
+            <a href="{{ path('app_admin_resource') }}"
+               class="group flex flex-col rounded-md border border-gray-200 p-6 hover:border-primary hover:bg-gray-50">
+                <div class="flex items-center gap-3 pb-2">
+                    {{ ux_icon('lucide:layout-grid', { class: 'h-6 w-6 shrink-0 text-primary' }) }}
+                    <span class="text-lg font-bold">Plätze &amp; Räume</span>
+                </div>
+                <p class="text-sm text-gray-500 pb-4">
+                    Schreibtische, Parkplätze und Räume anlegen und bearbeiten.
+                </p>
+            </a>
         {% endif %}
     </div>
 
diff --git a/tests/Controller/Admin/ResourceAdminControllerTest.php b/tests/Controller/Admin/ResourceAdminControllerTest.php
new file mode 100644
index 0000000..c23e6c8
--- /dev/null
+++ b/tests/Controller/Admin/ResourceAdminControllerTest.php
@@ -0,0 +1,322 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Admin;
+
+use App\Entity\Booking;
+use App\Entity\Resource;
+use App\Entity\ResourceGroup;
+use App\Entity\User;
+use App\Enum\ResourceType;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Bundle\FrameworkBundle\KernelBrowser;
+use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
+use Symfony\Component\HttpFoundation\Response;
+
+/**
+ * Maintaining what can be booked: resources and the rooms they sit in.
+ */
+class ResourceAdminControllerTest extends WebTestCase
+{
+    private KernelBrowser $client;
+    private EntityManagerInterface $em;
+
+    protected function setUp(): void
+    {
+        $this->client = self::createClient();
+        $this->client->disableReboot();
+        $this->em = self::getContainer()->get(EntityManagerInterface::class);
+        $this->em->getConnection()->beginTransaction();
+    }
+
+    protected function tearDown(): void
+    {
+        $this->em->getConnection()->rollBack();
+        parent::tearDown();
+    }
+
+    public function testAnEmployeeCannotReachIt(): void
+    {
+        $this->client->loginUser($this->user('anna@ep-reisen.de'));
+
+        $this->client->request('GET', '/admin/resources');
+        self::assertResponseStatusCodeSame(Response::HTTP_FORBIDDEN);
+
+        // Not as htmx: an htmx request gets the error modal instead of the bare status.
+        $this->client->request('GET', '/admin/resources/new/desk');
+        self::assertResponseStatusCodeSame(Response::HTTP_FORBIDDEN);
+    }
+
+    public function testTheListShowsRoomsAndRetiredResources(): void
+    {
+        $room = $this->group('Raum Nord');
+        $this->resource('Schreibtisch 01', $room);
+        $this->resource('Schreibtisch 02', $room)->setActive(false);
+        $this->em->flush();
+        $this->client->loginUser($this->admin());
+
+        $crawler = $this->client->request('GET', '/admin/resources');
+
+        self::assertResponseIsSuccessful();
+        $desks = $crawler->filter('[data-type="desk"]')->text();
+        self::assertStringContainsString('Raum Nord', $desks);
+        self::assertStringContainsString('Schreibtisch 01', $desks);
+        self::assertStringContainsString('Schreibtisch 02 nicht buchbar', preg_replace('/\s+/', ' ', $desks) ?? '');
+    }
+
+    public function testCreatingAResourceInARoom(): void
+    {
+        $room = $this->group('Raum Nord');
+        $this->client->loginUser($this->admin());
+
+        $response = $this->submit('/admin/resources/new/desk', 'resource_form', ['label' => 'Schreibtisch 13', 'group' => (string) $room->getId()]);
+
+        self::assertSame('/admin/resources', $response->headers->get('HX-Redirect'));
+        $created = $this->em->getRepository(Resource::class)->findOneBy(['label' => 'Schreibtisch 13']);
+        self::assertNotNull($created);
+        self::assertSame(ResourceType::DESK, $created->getType());
+        self::assertSame($room->getId(), $created->getGroup()?->getId());
+        self::assertTrue($created->isActive());
+    }
+
+    public function testADuplicateLabelIsRejectedInTheModal(): void
+    {
+        $this->resource('Schreibtisch 01');
+        $this->client->loginUser($this->admin());
+
+        $response = $this->submit('/admin/resources/new/desk', 'resource_form', ['label' => 'Schreibtisch 01']);
+
+        self::assertSame(Response::HTTP_UNPROCESSABLE_ENTITY, $response->getStatusCode());
+        self::assertStringContainsString('bereits vergeben', (string) $response->getContent());
+    }
+
+    /**
+     * The same label is fine for another type -- uniqueness is per type, like the database's.
+     */
+    public function testTheSameLabelMayExistForAnotherType(): void
+    {
+        $this->resource('A1');
+        $this->client->loginUser($this->admin());
+
+        $response = $this->submit('/admin/resources/new/parking', 'resource_form', ['label' => 'A1']);
+
+        self::assertSame('/admin/resources', $response->headers->get('HX-Redirect'));
+    }
+
+    /**
+     * The group choices are limited to the resource's type, so a parking area cannot be forced
+     * onto a desk by editing the request.
+     */
+    public function testARoomOfAnotherTypeIsRejected(): void
+    {
+        $area = $this->group('Tiefgarage', ResourceType::PARKING);
+        $this->client->loginUser($this->admin());
+
+        $response = $this->submit('/admin/resources/new/desk', 'resource_form', ['label' => 'Schreibtisch 13', 'group' => (string) $area->getId()]);
+
+        self::assertSame(Response::HTTP_UNPROCESSABLE_ENTITY, $response->getStatusCode());
+        self::assertNull($this->em->getRepository(Resource::class)->findOneBy(['label' => 'Schreibtisch 13']));
+    }
+
+    public function testAnUnknownTypeIsNotFound(): void
+    {
+        $this->client->loginUser($this->admin());
+
+        $this->client->request('GET', '/admin/resources/new/boat');
+
+        self::assertResponseStatusCodeSame(Response::HTTP_NOT_FOUND);
+    }
+
+    /**
+     * Retiring keeps the bookings and says how many are left, and the resource leaves the plan.
+     */
+    public function testRetiringAResourceWithUpcomingBookings(): void
+    {
+        $desk = $this->resource('Schreibtisch 01');
+        $this->em->persist(new Booking($this->user('bea@ep-reisen.de'), $desk, new \DateTimeImmutable('+1 day')));
+        $this->em->flush();
+        $this->client->loginUser($this->admin());
+
+        // An unticked checkbox is simply absent from the submit.
+        $response = $this->submit(\sprintf('/admin/resources/%d/edit', $desk->getId()), 'resource_form', ['label' => 'Schreibtisch 01']);
+
+        self::assertSame('/admin/resources', $response->headers->get('HX-Redirect'));
+        $desk = $this->reload($desk);
+        self::assertFalse($desk->isActive());
+        self::assertCount(1, $this->em->getRepository(Booking::class)->findBy(['resource' => $desk]));
+
+        $this->client->request('GET', '/admin/resources');
+        self::assertStringContainsString('1 bestehende Buchungen ab heute bleiben erhalten', (string) $this->client->getResponse()->getContent());
+
+        $board = $this->client->request('GET', '/book/desk');
+        self::assertCount(0, $board->filter('[data-spot]'));
+    }
+
+    public function testReactivatingAResource(): void
+    {
+        $desk = $this->resource('Schreibtisch 01');
+        $desk->setActive(false);
+        $this->em->flush();
+        $this->client->loginUser($this->admin());
+
+        $this->submit(\sprintf('/admin/resources/%d/edit', $desk->getId()), 'resource_form', ['label' => 'Schreibtisch 01', 'active' => '1']);
+
+        self::assertTrue($this->reload($desk)->isActive());
+    }
+
+    public function testANewRoomIsPrefilledToComeLast(): void
+    {
+        $this->group('Raum Nord', position: 0);
+        $this->group('Raum Süd', position: 4);
+        $this->client->loginUser($this->admin());
+
+        $crawler = $this->client->request('GET', '/admin/resource-groups/new/desk', server: ['HTTP_HX-Request' => 'true']);
+
+        self::assertSame('5', $crawler->filter('#resource_group_form_position')->attr('value'));
+    }
+
+    public function testCreatingAndRenamingARoom(): void
+    {
+        $this->client->loginUser($this->admin());
+
+        $response = $this->submit('/admin/resource-groups/new/desk', 'resource_group_form', ['label' => 'Raum West', 'position' => '2']);
+        self::assertSame('/admin/resources', $response->headers->get('HX-Redirect'));
+
+        $room = $this->em->getRepository(ResourceGroup::class)->findOneBy(['label' => 'Raum West']);
+        self::assertNotNull($room);
+        self::assertSame(ResourceType::DESK, $room->getType());
+
+        $this->submit(\sprintf('/admin/resource-groups/%d/edit', $room->getId()), 'resource_group_form', ['label' => 'Raum Ost', 'position' => '1']);
+
+        $room = $this->reload($room);
+        self::assertSame('Raum Ost', $room->getLabel());
+        self::assertSame(1, $room->getPosition());
+    }
+
+    public function testDeletingAnEmptyRoom(): void
+    {
+        $room = $this->group('Raum Nord');
+        $id = $room->getId();
+        $this->client->loginUser($this->admin());
+        $uri = \sprintf('/admin/resource-groups/%d/delete', $id);
+
+        $this->client->request('POST', $uri, ['_token' => $this->confirmationToken($uri)], server: ['HTTP_HX-Request' => 'true']);
+
+        self::assertSame('/admin/resources', $this->client->getResponse()->headers->get('HX-Redirect'));
+        $this->em->clear();
+        self::assertNull($this->em->find(ResourceGroup::class, $id));
+    }
+
+    /**
+     * A retired resource still sits in the room, so it counts.
+     */
+    public function testARoomWithResourcesCannotBeDeleted(): void
+    {
+        $room = $this->group('Raum Nord');
+        $this->resource('Schreibtisch 01', $room)->setActive(false);
+        $this->em->flush();
+        $this->client->loginUser($this->admin());
+
+        $crawler = $this->client->request('GET', '/admin/resources');
+        self::assertCount(0, $crawler->filter(\sprintf('[hx-get="/admin/resource-groups/%d/delete"]', $room->getId())));
+
+        $this->client->request('POST', \sprintf('/admin/resource-groups/%d/delete', $room->getId()), ['_token' => 'whatever']);
+        self::assertResponseStatusCodeSame(Response::HTTP_FORBIDDEN);
+    }
+
+    public function testTheDashboardLinksHereForAdminsOnly(): void
+    {
+        $this->client->loginUser($this->user('anna@ep-reisen.de'));
+        self::assertCount(0, $this->client->request('GET', '/')->filter('a[href="/admin/resources"]'));
+
+        $this->client->loginUser($this->admin());
+        self::assertCount(1, $this->client->request('GET', '/')->filter('a[href="/admin/resources"]'));
+    }
+
+    /**
+     * Opens the modal, then posts the given fields with its CSRF token -- the round trip a
+     * browser makes.
+     *
+     * @param array<string, string> $fields
+     */
+    private function submit(string $uri, string $formName, array $fields): Response
+    {
+        $crawler = $this->client->request('GET', $uri, server: ['HTTP_HX-Request' => 'true']);
+        self::assertResponseIsSuccessful();
+
+        $fields['_token'] = $crawler->filter(\sprintf('#%s__token', $formName))->attr('value');
+        $this->client->request('POST', $uri, [$formName => $fields], server: ['HTTP_HX-Request' => 'true']);
+
+        return $this->client->getResponse();
+    }
+
+    private function confirmationToken(string $uri): string
+    {
+        $crawler = $this->client->request('GET', $uri, server: ['HTTP_HX-Request' => 'true']);
+        self::assertResponseIsSuccessful();
+
+        $vals = $crawler->filter('#htmx-confirmation-modal [hx-post]')->attr('hx-vals');
+
+        return json_decode((string) $vals, true, flags: \JSON_THROW_ON_ERROR)['_token'];
+    }
+
+    /**
+     * Each request resets the entity manager, so what a test holds is detached afterwards.
+     *
+     * @template T of Resource|ResourceGroup
+     *
+     * @param T $entity
+     *
+     * @return T
+     */
+    private function reload(Resource|ResourceGroup $entity): Resource|ResourceGroup
+    {
+        $fresh = $this->em->find($entity::class, $entity->getId());
+        self::assertNotNull($fresh);
+
+        return $fresh;
+    }
+
+    private function group(string $label, ResourceType $type = ResourceType::DESK, int $position = 0): ResourceGroup
+    {
+        $group = new ResourceGroup($type, $label, $position);
+        $this->em->persist($group);
+        $this->em->flush();
+
+        return $group;
+    }
+
+    private function resource(string $label, ?ResourceGroup $group = null): Resource
+    {
+        $resource = new Resource(ResourceType::DESK, $label);
+        $resource->setGroup($group);
+        $this->em->persist($resource);
+        $this->em->flush();
+
+        return $resource;
+    }
+
+    private function admin(): User
+    {
+        return $this->user('chef@ep-reisen.de', ['ROLE_ADMIN']);
+    }
+
+    /**
+     * @param list<string> $roles
+     */
+    private function user(string $email, array $roles = ['ROLE_EMPLOYEE']): User
+    {
+        $existing = $this->em->getRepository(User::class)->findOneBy(['email' => $email]);
+        if (null !== $existing) {
+            return $existing;
+        }
+
+        $user = new User($email, 'Test');
+        $user->setRoles($roles);
+        $this->em->persist($user);
+        $this->em->flush();
+
+        return $user;
+    }
+}