diff --git a/app/Http/Controllers/Apis/Protected/Summit/OAuth2SummitEventsApiController.php b/app/Http/Controllers/Apis/Protected/Summit/OAuth2SummitEventsApiController.php
index f59f3aee..e3c5f7e9 100644
--- a/app/Http/Controllers/Apis/Protected/Summit/OAuth2SummitEventsApiController.php
+++ b/app/Http/Controllers/Apis/Protected/Summit/OAuth2SummitEventsApiController.php
@@ -23,6 +23,7 @@ use Illuminate\Support\Facades\Validator;
 use libs\utils\HTMLCleaner;
 use models\exceptions\EntityNotFoundException;
 use models\exceptions\ValidationException;
+use models\main\IMemberRepository;
 use models\oauth2\IResourceServerContext;
 use models\summit\IEventFeedbackRepository;
 use models\summit\ISpeakerRepository;
@@ -62,6 +63,11 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
      */
     private $event_feedback_repository;
 
+    /**
+     * @var IMemberRepository
+     */
+    private $member_repository;
+
 
     public function __construct
     (
@@ -69,6 +75,7 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
         ISummitEventRepository $event_repository,
         ISpeakerRepository $speaker_repository,
         IEventFeedbackRepository $event_feedback_repository,
+        IMemberRepository $member_repository,
         ISummitService $service,
         IResourceServerContext $resource_server_context
     ) {
@@ -77,6 +84,7 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
         $this->speaker_repository        = $speaker_repository;
         $this->event_repository          = $event_repository;
         $this->event_feedback_repository = $event_feedback_repository;
+        $this->member_repository         = $member_repository;
         $this->service                   = $service;
     }
 
@@ -408,6 +416,12 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
             if(!Request::isJson()) return $this->error400();
             $data = Input::json();
 
+            $current_member = null;
+            $member_id = $this->resource_server_context->getCurrentUserExternalId();
+            if (!is_null($member_id)){
+                $current_member = $this->member_repository->getById($member_id);
+            }
+
             $rules = [
                 // summit event rules
                 'title'                          => 'sometimes|string|max:100',
@@ -427,13 +441,14 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
                 'tags'                           => 'sometimes|string_array',
                 'sponsors'                       => 'sometimes|int_array',
                 // presentation rules
-                'attendees_expected_learnt'      =>  'sometimes|string|max:1000',
-                'attending_media'                =>  'sometimes|boolean',
-                'to_record'                      =>  'sometimes|boolean',
-                'speakers'                       =>  'sometimes|int_array',
-                'moderator_speaker_id'           =>  'sometimes|integer',
+                'attendees_expected_learnt'      => 'sometimes|string|max:1000',
+                'attending_media'                => 'sometimes|boolean',
+                'to_record'                      => 'sometimes|boolean',
+                'speakers'                       => 'sometimes|int_array',
+                'moderator_speaker_id'           => 'sometimes|integer',
                 // group event
-                'groups'                         =>  'sometimes|int_array',
+                'groups'                         => 'sometimes|int_array',
+                'occupancy'                      => 'sometimes|in:EMPTY,25%,50%,75%,FULL'
             ];
 
             // Creates a Validator instance and validates the data.
@@ -454,7 +469,7 @@ final class OAuth2SummitEventsApiController extends OAuth2ProtectedController
                 'social_summary',
             ];
 
-            $event = $this->service->updateEvent($summit, $event_id, HTMLCleaner::cleanData($data->all(), $fields));
+            $event = $this->service->updateEvent($summit, $event_id, HTMLCleaner::cleanData($data->all(), $fields), $current_member);
 
             return $this->ok(SerializerRegistry::getInstance()->getSerializer($event)->serialize());
 
diff --git a/app/Http/routes.php b/app/Http/routes.php
index 443c829c..f7a0191d 100644
--- a/app/Http/routes.php
+++ b/app/Http/routes.php
@@ -258,7 +258,7 @@ Route::group([
 
                     Route::get('', 'OAuth2SummitEventsApiController@getEvent');
                     Route::get('/published', [ 'middleware' => 'cache:'.Config::get('cache_api_response.get_published_event_response_lifetime', 300), 'uses' => 'OAuth2SummitEventsApiController@getScheduledEvent']);
-                    Route::put('', [ 'middleware' => 'auth.user:administrators|summit-front-end-administrators', 'uses' => 'OAuth2SummitEventsApiController@updateEvent' ]);
+                    Route::put('', [ 'middleware' => 'auth.user:administrators|summit-front-end-administrators|summit-room-administrators', 'uses' => 'OAuth2SummitEventsApiController@updateEvent' ]);
                     Route::delete('', [ 'middleware' => 'auth.user:administrators|summit-front-end-administrators', 'uses' => 'OAuth2SummitEventsApiController@deleteEvent' ]);
                     Route::put('/publish', [ 'middleware' => 'auth.user:administrators|summit-front-end-administrators', 'uses' => 'OAuth2SummitEventsApiController@publishEvent']);
                     Route::delete('/publish', [ 'middleware' => 'auth.user:administrators|summit-front-end-administrators', 'uses' => 'OAuth2SummitEventsApiController@unPublishEvent']);
diff --git a/app/ModelSerializers/BaseSerializerTypeSelector.php b/app/ModelSerializers/BaseSerializerTypeSelector.php
index 63c9eff0..b023b46e 100644
--- a/app/ModelSerializers/BaseSerializerTypeSelector.php
+++ b/app/ModelSerializers/BaseSerializerTypeSelector.php
@@ -11,6 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
+use App\Models\Foundation\Main\IGroup;
 use models\main\IMemberRepository;
 use models\oauth2\IResourceServerContext;
 use models\main\Group;
@@ -54,7 +55,7 @@ final class BaseSerializerTypeSelector implements ISerializerTypeSelector
         $serializer_type = SerializerRegistry::SerializerType_Public;
         $current_member_id = $this->resource_server_context->getCurrentUserExternalId();
         if(!is_null($current_member_id) && $member = $this->member_repository->getById($current_member_id)){
-            if($member->isOnGroup(Group::SummitAdministrators)){
+            if($member->isOnGroup(IGroup::SummitAdministrators)){
                 $serializer_type = SerializerRegistry::SerializerType_Private;
             }
         }
diff --git a/app/Models/Foundation/Main/Group.php b/app/Models/Foundation/Main/Group.php
index 3fcc5a3c..9c00255b 100644
--- a/app/Models/Foundation/Main/Group.php
+++ b/app/Models/Foundation/Main/Group.php
@@ -23,10 +23,6 @@ use models\utils\SilverstripeBaseModel;
  */
 class Group extends SilverstripeBaseModel
 {
-    const AdminGroupCode        = 'administrators';
-    const CommunityMembersCode  = 'community-members';
-    const FoundationMembersCode = 'foundation-members';
-    const SummitAdministrators  = 'summit-front-end-administrators';
 
     public function __construct(){
         parent::__construct();
diff --git a/app/Models/Foundation/Main/IGroup.php b/app/Models/Foundation/Main/IGroup.php
new file mode 100644
index 00000000..f98314e3
--- /dev/null
+++ b/app/Models/Foundation/Main/IGroup.php
@@ -0,0 +1,28 @@
+<?php namespace App\Models\Foundation\Main;
+
+/**
+ * Copyright 2018 OpenStack Foundation
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+
+/**
+ * Interface IGroup
+ * @package App\Models\Foundation\Main
+ */
+interface IGroup
+{
+    const Administrators           = 'administrators';
+    const CommunityMembers         = 'community-members';
+    const FoundationMembers        = 'foundation-members';
+    const SummitAdministrators     = 'summit-front-end-administrators';
+    const SummitRoomAdministrators = 'summit-room-administrators';
+}
\ No newline at end of file
diff --git a/app/Models/Foundation/Main/Member.php b/app/Models/Foundation/Main/Member.php
index b231c28f..facabc5a 100644
--- a/app/Models/Foundation/Main/Member.php
+++ b/app/Models/Foundation/Main/Member.php
@@ -11,6 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
+use App\Models\Foundation\Main\IGroup;
 use Models\Foundation\Main\CCLA\Team;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Criteria;
@@ -580,7 +581,7 @@ class Member extends SilverstripeBaseModel
      */
     public function isAdmin()
     {
-        $admin_group = $this->getGroupByCode(Group::AdminGroupCode);
+        $admin_group = $this->getGroupByCode(IGroup::Administrators);
         return $admin_group != false && !is_null($admin_group);
     }
 
diff --git a/app/Models/Foundation/Summit/Events/SummitEvent.php b/app/Models/Foundation/Summit/Events/SummitEvent.php
index 00bd4810..c86dea9c 100644
--- a/app/Models/Foundation/Summit/Events/SummitEvent.php
+++ b/app/Models/Foundation/Summit/Events/SummitEvent.php
@@ -58,6 +58,12 @@ class SummitEvent extends SilverstripeBaseModel
      */
     protected $social_summary;
 
+    /**
+     * @ORM\Column(name="Occupancy", type="string")
+     * @var string
+     */
+    protected $occupancy;
+
     /**
      * @ORM\Column(name="StartDate", type="datetime")
      * @var \DateTime
@@ -907,4 +913,21 @@ class SummitEvent extends SilverstripeBaseModel
         $this->rsvp_max_user_wait_list_number = $rsvp_max_user_wait_list_number;
     }
 
+    /**
+     * @return string
+     */
+    public function getOccupancy()
+    {
+        return $this->occupancy;
+    }
+
+    /**
+     * @param string $occupancy
+     */
+    public function setOccupancy($occupancy)
+    {
+        $this->occupancy = $occupancy;
+    }
+
+
 }
\ No newline at end of file
diff --git a/app/Permissions/IPermissionsManager.php b/app/Permissions/IPermissionsManager.php
new file mode 100644
index 00000000..f2dc0f92
--- /dev/null
+++ b/app/Permissions/IPermissionsManager.php
@@ -0,0 +1,28 @@
+<?php namespace App\Permissions;
+/**
+ * Copyright 2018 OpenStack Foundation
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+use models\main\Member;
+/**
+ * Interface IPermissionsManager
+ * @package App\Permissions
+ */
+interface IPermissionsManager
+{
+    /**
+     * @param Member $current_user
+     * @param string $entity_name
+     * @param array $data
+     * @return bool
+     */
+    public function canEditFields(Member $current_user, $entity_name, array $data);
+}
\ No newline at end of file
diff --git a/app/Permissions/PermissionsManager.php b/app/Permissions/PermissionsManager.php
new file mode 100644
index 00000000..2b002662
--- /dev/null
+++ b/app/Permissions/PermissionsManager.php
@@ -0,0 +1,82 @@
+<?php namespace App\Permissions;
+/**
+ * Copyright 2018 OpenStack Foundation
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+use models\main\Member;
+use Symfony\Component\Yaml\Exception\ParseException;
+use Symfony\Component\Yaml\Yaml;
+/**
+ * Class PermissionsManager
+ * @package App\Permissions
+ */
+final class PermissionsManager implements IPermissionsManager
+{
+    /**
+     * @var array
+     */
+    private $config = [];
+
+    const AllFieldsWillCard = "__all__";
+
+    private function loadConfiguration(){
+        if(count($this->config) > 0 ) return;
+
+        $path = sprintf("%s/permissions.yml", dirname(__FILE__));
+        $yaml = Yaml::parse(file_get_contents($path));
+        if(!is_null($yaml) && count($yaml))
+        {
+            foreach($yaml as $entities => $entity){
+                foreach ($entity as $permissions_per_role){
+                    $entity_name = array_keys($entity)[0];
+                    $entity_config = [];
+                    foreach ($permissions_per_role as $permission_per_role){
+                        $role = array_keys($permission_per_role)[0];
+                        $entity_config[$role] = [];
+                        foreach($permission_per_role as $permissions){
+                            foreach($permissions as $permission)
+                                $entity_config[$role][] = $permission;
+                        }
+                    }
+                    $this->config[$entity_name] = $entity_config;
+                }
+            }}
+
+    }
+    /**
+     * @param Member $current_user
+     * @param string $entity_name
+     * @param array $data
+     * @return bool
+     */
+    public function canEditFields(Member $current_user, $entity_name, array $data){
+        $this->loadConfiguration();
+        $groups = $current_user->getGroupsCodes();
+
+        if(!isset($this->config[$entity_name]))
+            throw new \InvalidArgumentException(sprintf("entity %s does not has a configuration set", $entity_name));
+
+        $entity_config = $this->config[$entity_name];
+
+        foreach($groups as $group_code) {
+            if(!isset($entity_config[$group_code])) continue;
+            $allowed_fields = $entity_config[$group_code];
+            if(count($allowed_fields) == 0) return false;
+            if(in_array(self::AllFieldsWillCard, $allowed_fields)) return true;
+            $fields = array_keys($data);
+            $diff = array_diff($fields, $allowed_fields);
+            if(count($diff) > 0)
+                return false;
+            return true;
+        }
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/app/Permissions/permissions.yml b/app/Permissions/permissions.yml
new file mode 100644
index 00000000..01865856
--- /dev/null
+++ b/app/Permissions/permissions.yml
@@ -0,0 +1,13 @@
+# here you define per Entity ClassName allowed fields to edit per user role
+- SummitEvent:
+  - administrators:
+    - __all__
+  - summit-front-end-administrators:
+    - __all__
+  - summit-room-administrators:
+    - occupancy
+- Presentation:
+  - administrators:
+    - __all__
+  - summit-front-end-administrators:
+    - __all__
diff --git a/app/Repositories/Summit/DoctrineSummitEventRepository.php b/app/Repositories/Summit/DoctrineSummitEventRepository.php
index cf190d27..840a2b3c 100644
--- a/app/Repositories/Summit/DoctrineSummitEventRepository.php
+++ b/app/Repositories/Summit/DoctrineSummitEventRepository.php
@@ -11,6 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
+use App\Models\Foundation\Main\IGroup;
 use Doctrine\ORM\Tools\Pagination\Paginator;
 use models\main\Group;
 use models\summit\ISummitEventRepository;
@@ -214,7 +215,7 @@ final class DoctrineSummitEventRepository
             $query = $query->leftJoin('sp.registration_request', "sprr", Join::LEFT_JOIN);
         }
 
-        $can_view_private_events = self::isCurrentMemberOnGroup(Group::SummitAdministrators);
+        $can_view_private_events = self::isCurrentMemberOnGroup(IGroup::SummitAdministrators);
 
         if(!$can_view_private_events){
             $query = $query
@@ -305,7 +306,7 @@ final class DoctrineSummitEventRepository
         }
 
 
-        $can_view_private_events = self::isCurrentMemberOnGroup(Group::SummitAdministrators);
+        $can_view_private_events = self::isCurrentMemberOnGroup(IGroup::SummitAdministrators);
 
         if(!$can_view_private_events){
             $query = $query
diff --git a/app/Services/Model/ISummitService.php b/app/Services/Model/ISummitService.php
index c40dee57..66b8a3f5 100644
--- a/app/Services/Model/ISummitService.php
+++ b/app/Services/Model/ISummitService.php
@@ -40,9 +40,10 @@ interface ISummitService
      * @param Summit $summit
      * @param int $event_id
      * @param array $data
+     * @param null|Member $current_member
      * @return SummitEvent
      */
-    public function updateEvent(Summit $summit, $event_id, array $data);
+    public function updateEvent(Summit $summit, $event_id, array $data, Member $current_member = null);
 
     /**
      * @param Summit $summit
diff --git a/app/Services/Model/SummitService.php b/app/Services/Model/SummitService.php
index 873d7dcb..a7ea4029 100644
--- a/app/Services/Model/SummitService.php
+++ b/app/Services/Model/SummitService.php
@@ -21,6 +21,7 @@ use App\Http\Utils\FileUploader;
 use App\Models\Foundation\Summit\Factories\SummitFactory;
 use App\Models\Foundation\Summit\Repositories\IDefaultSummitEventTypeRepository;
 use App\Models\Utils\IntervalParser;
+use App\Permissions\IPermissionsManager;
 use App\Services\Model\AbstractService;
 use App\Services\Model\IFolderService;
 use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
@@ -161,6 +162,11 @@ final class SummitService extends AbstractService implements ISummitService
      */
     private $default_event_types_repository;
 
+    /**
+     * @var IPermissionsManager
+     */
+    private $permissions_manager;
+
     /**
      * SummitService constructor.
      * @param ISummitRepository $summit_repository
@@ -178,6 +184,7 @@ final class SummitService extends AbstractService implements ISummitService
      * @param ICompanyRepository $company_repository
      * @param IGroupRepository $group_repository,
      * @param IDefaultSummitEventTypeRepository $default_event_types_repository
+     * @param IPermissionsManager $permissions_manager
      * @param ITransactionService $tx_service
      */
     public function __construct
@@ -197,6 +204,7 @@ final class SummitService extends AbstractService implements ISummitService
         ICompanyRepository                $company_repository,
         IGroupRepository                  $group_repository,
         IDefaultSummitEventTypeRepository $default_event_types_repository,
+        IPermissionsManager               $permissions_manager,
         ITransactionService               $tx_service
     )
     {
@@ -216,6 +224,7 @@ final class SummitService extends AbstractService implements ISummitService
         $this->company_repository                    = $company_repository;
         $this->group_repository                      = $group_repository;
         $this->default_event_types_repository        = $default_event_types_repository;
+        $this->permissions_manager                   = $permissions_manager;
     }
 
     /**
@@ -529,11 +538,12 @@ final class SummitService extends AbstractService implements ISummitService
      * @param Summit $summit
      * @param int $event_id
      * @param array $data
+     * @param null|Member $current_member
      * @return SummitEvent
      */
-    public function updateEvent(Summit $summit, $event_id, array $data)
+    public function updateEvent(Summit $summit, $event_id, array $data, Member $current_member = null)
     {
-        return $this->saveOrUpdateEvent($summit, $data, $event_id);
+        return $this->saveOrUpdateEvent($summit, $data, $event_id, $current_member);
     }
 
     /**
@@ -616,16 +626,25 @@ final class SummitService extends AbstractService implements ISummitService
         return true;
     }
 
+
     /**
      * @param Summit $summit
      * @param array $data
      * @param null|int $event_id
+     * @param Member|null $current_member
      * @return SummitEvent
+     * @throws EntityNotFoundException
+     * @throws ValidationException
+     * @throws Exception
      */
-    private function saveOrUpdateEvent(Summit $summit, array $data, $event_id = null)
+    private function saveOrUpdateEvent(Summit $summit, array $data, $event_id = null, Member $current_member = null)
     {
 
-        return $this->tx_service->transaction(function () use ($summit, $data, $event_id) {
+        return $this->tx_service->transaction(function () use ($summit, $data, $event_id, $current_member) {
+
+            if(!is_null($current_member) && !$this->permissions_manager->canEditFields($current_member, 'SummitEvent', $data)){
+                throw new ValidationException(sprintf("user %s cant set requested summit event fields", $current_member->getId()));
+            }
 
             $event_type = null;
 
@@ -721,6 +740,9 @@ final class SummitService extends AbstractService implements ISummitService
             if (isset($data['social_description']))
                 $event->setSocialSummary(strip_tags(trim($data['social_description'])));
 
+            if (isset($data['occupancy']))
+                $event->setOccupancy($data['occupancy']);
+
             $event->setAllowFeedBack(isset($data['allow_feedback'])?
                 filter_var($data['allow_feedback'], FILTER_VALIDATE_BOOLEAN) :
                 false);
diff --git a/app/Services/ServicesProvider.php b/app/Services/ServicesProvider.php
index 281a29c4..5e56f261 100644
--- a/app/Services/ServicesProvider.php
+++ b/app/Services/ServicesProvider.php
@@ -11,6 +11,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
+use App\Permissions\IPermissionsManager;
+use App\Permissions\PermissionsManager;
 use App\Services\Apis\CalendarSync\ICalendarSyncRemoteFacadeFactory;
 use App\Services\Apis\GoogleGeoCodingAPI;
 use App\Services\Apis\IGeoCodingAPI;
@@ -72,6 +74,8 @@ final class ServicesProvider extends ServiceProvider
     {
         App::singleton(ICacheService::class, RedisCacheService::class);
 
+        App::singleton(IPermissionsManager::class, PermissionsManager::class);
+
         App::singleton(\libs\utils\ITransactionService::class, function(){
             return new \services\utils\DoctrineTransactionService('ss');
         });
diff --git a/tests/OAuth2SummitEventsApiTest.php b/tests/OAuth2SummitEventsApiTest.php
index 02020807..581c7991 100644
--- a/tests/OAuth2SummitEventsApiTest.php
+++ b/tests/OAuth2SummitEventsApiTest.php
@@ -335,6 +335,43 @@ final class OAuth2SummitEventsApiTest extends ProtectedApiTest
         return $event;
     }
 
+    public function testUpdateEventOccupancy(){
+
+        $params = array
+        (
+            'id' => 23,
+            'event_id' => 20345,
+        );
+
+        $data = [
+            'occupancy' => '25%'
+        ];
+
+        $headers = array
+        (
+            "HTTP_Authorization" => " Bearer " . $this->access_token,
+            "CONTENT_TYPE" => "application/json"
+        );
+
+        $response = $this->action
+        (
+            "PUT",
+            "OAuth2SummitEventsApiController@updateEvent",
+            $params,
+            array(),
+            array(),
+            array(),
+            $headers,
+            json_encode($data)
+        );
+
+        $content = $response->getContent();
+        $this->assertResponseStatus(200);
+        $event = json_decode($content);
+        $this->assertTrue($event->id > 0);
+        return $event;
+    }
+
     public function testUnPublishEvent()
     {
         $event = $this->testPublishEvent(1461529800, 1461533400);