house
+----------------------------------------------+
| id |     title    |       description        |
+----------------------------------------------+
| 1  | some title 1 |    some description 1    |
+----------------------------------------------+
| 2  | some title 2 |    some description 2    |
+----------------------------------------------+

       type
+----------------+
| id |   name    |
+----------------+
| 1  | shortstay |
+----------------+
| 2  | rent      |
+----------------+
| 4  | sell      |
+----------------+

                  house_types
+-----------------------------------+
| id | house_id | type_id |  price  |
+-----------------------------------+
| 1  |    1     |   2     | 1000    |
+-----------------------------------+
| 2  |    1     |   3     | 1000000 |
+-----------------------------------+
| 3  |    2     |   1     | 100     |
+-----------------------------------+
| 4  |    2     |   3     | 200000  |
+-----------------------------------+

class House extends EntityBase
{
    /**
     * @ORMOneToMany(targetEntity="AppBundleEntityHouseHasTypes", mappedBy="houses", cascade={"persist","remove"})
     */
    protected $hasTypes;

class Type extends EntityBase
{
    /**
     * @ORMOneToMany(targetEntity="AppBundleEntityHouseHasTypes", mappedBy="types", cascade={"persist","remove"})
     */
    protected $hasHouses;

class HouseHasTypes extends EntityBase
{
    /**
     * @ORMManyToOne(targetEntity="AppBundleEntityHouse", cascade={"persist"}, fetch="EAGER")
     * @ORMJoinColumn(name="house_id", referencedColumnName="id", nullable=true)
     */
    protected $houses;
    /**
     * @ORMManyToOne(targetEntity="AppBundleEntityType", cascade={"persist","remove"}, fetch="EAGER" )
     * @ORMJoinColumn(name="type_id", referencedColumnName="id",nullable=true)
     */
    protected $types;
    /**
     * @var int
     *
     * @ORMColumn(name="price", type="integer")
     */
    protected $price;

$builder
...
->add('hasTypes', EntityType::class, array(
                'required' => true,
                'class' => Type::class,
                'expanded' => true,
                'multiple' => true,
            ))