diff --git a/estate/models/estate_property.py b/estate/models/estate_property.py
index b8f673b..0958ca2 100644
--- a/estate/models/estate_property.py
+++ b/estate/models/estate_property.py
@@ -104,6 +104,8 @@ class EstateProperty(models.Model):
         if self.exists():
             if self.state == 'cancelled':
                 raise exceptions.UserError('A cancelled property cannot be sold')
+            if "accepted" not in self.offer_ids.mapped("state"):
+                raise exceptions.ValidationError('Cannot sell a property with no accepted offers')
             else:
                 self.state = 'sold'
             return True
@@ -118,4 +120,4 @@ class EstateProperty(models.Model):
                 self.state = 'cancelled'
             return True
         else:
-            raise exceptions.MissingError('Property not found')
+            raise exceptions.MissingError('Property not found')
\ No newline at end of file
diff --git a/estate/models/estate_property_offer.py b/estate/models/estate_property_offer.py
index 83c8535..6e417df 100644
--- a/estate/models/estate_property_offer.py
+++ b/estate/models/estate_property_offer.py
@@ -29,8 +29,11 @@ class EstatePropertyOffer(models.Model):
     @api.model_create_multi
     def create(self, vals_list):
         for vals in vals_list:
-            if self.env['estate.property'].browse(vals['property_id']).state == 'new':
-                self.env['estate.property'].browse(vals['property_id']).write({'state': 'offer_received'})
+            prop = self.env['estate.property'].browse(vals['property_id'])
+            if prop.state == 'sold':
+                raise exceptions.UserError('Cannot create offer on a sold property')
+            elif prop.state == 'new':
+                prop.write({'state': 'offer_received'})
         return super().create(vals_list)
     
     # ------------- Compute methods  ------------------------- #
diff --git a/estate/tests/__init__.py b/estate/tests/__init__.py
new file mode 100644
index 0000000..38e2a53
--- /dev/null
+++ b/estate/tests/__init__.py
@@ -0,0 +1,3 @@
+# -*- coding: utf-8 -*-
+
+from . import test_property
\ No newline at end of file
diff --git a/estate/tests/test_property.py b/estate/tests/test_property.py
new file mode 100644
index 0000000..def9f69
--- /dev/null
+++ b/estate/tests/test_property.py
@@ -0,0 +1,104 @@
+from odoo import Command
+from odoo.exceptions import UserError, ValidationError
+from odoo.tests.common import Form, TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class EstateTestCase(TransactionCase):
+
+    @classmethod
+    def setUpClass(cls):
+        super(EstateTestCase, cls).setUpClass()
+
+        # Properties
+
+        cls.property = cls.env['estate.property'].create({
+            'name': "Sick house",
+            'description' : "Will not actually make you sick",
+            'postcode': '12345',
+            'expected_price': 1000000.00,
+            'living_area': '100',
+            'facades': 4,
+            'garage': False,
+            'garden': False,
+            'property_type_id': cls.env.ref('estate.property_type_commercial').id
+        })
+
+        # Partners
+
+        cls.buyman = cls.env['res.partner'].create({
+            'name': 'Buyman',
+        })
+        cls.poorman = cls.env['res.partner'].create({
+            'name': 'Buyman',
+        })
+        cls.wooman = cls.env['res.partner'].create({
+            'name': 'Wooman',
+        })
+
+        # Offers
+
+        cls.property_offer_1 = cls.env['estate.property.offer'].create({
+            'price': 500000.00,
+            'partner_id': cls.poorman.id,
+            'property_id': cls.property.id,
+        })
+
+        cls.property_offer_2 = cls.env['estate.property.offer'].create({
+            'price': 950000.50,
+            'partner_id': cls.buyman.id,
+            'property_id': cls.property.id,
+        })
+
+        cls.property.offer_ids = [cls.property_offer_1.id, cls.property_offer_2.id]
+
+    def test_offer_creation_if_sold(self):
+        self.property_offer_2.action_accept()
+        self.property.action_sold()
+
+        self.assertEqual('sold', self.property.state)
+        
+        with self.assertRaises(UserError):
+            self.env['estate.property.offer'].create({
+                'price': 10000.00,
+                'partner_id': self.poorman.id,
+                'property_id': self.property.id,
+            })
+
+    def test_sell_property_no_offer(self):
+        property = self.env['estate.property'].create({
+            'name': "Test house",
+            'postcode': '12345',
+            'expected_price': 1000000.00,
+            'living_area': '100',
+            'facades': 4,
+            'garage': False,
+            'garden': False,
+            'property_type_id': self.env.ref('estate.property_type_residential').id
+        })
+        
+        with self.assertRaises(ValidationError):
+            property.action_sold()
+        with self.assertRaises(ValidationError):
+            self.property.action_sold()
+
+    def test_reset_garden_area(self):
+        with Form(self.property) as property:
+            self.assertEqual(0, property.garden_area)
+            self.assertIs(False, property.garden_orientation)
+
+            property.garden = True
+
+            self.assertEqual(10, property.garden_area)
+            self.assertEqual('north', property.garden_orientation)
+
+            property.garden = False
+            self.assertEqual(0, property.garden_area)
+            self.assertIs(False, property.garden_orientation)
+            
+
+
+
+        
+        
\ No newline at end of file