House Learn programming Visual Basic (VB.net)

Imports System
Namespace Houses
    Class House
        Protected area As Integer
        Protected door As Door

        Public Sub New(ByVal area As Integer)
            Me.area = area
            door = New Door()
        End Sub

        Public Property Area As Integer
            Get
                Return area
            End Get
            Set(ByVal value As Integer)
                area = value
            End Set
        End Property

        Public Property Door As Door
            Get
                Return door
            End Get
            Set(ByVal value As Door)
                door = value
            End Set
        End Property

        Public Overridable Sub ShowData()
            Console.WriteLine("I am a house, my area is {0} m2.", area)
        End Sub
    End Class

    Class Door
        Protected color As String

        Public Sub New()
            color = "Brown"
        End Sub

        Public Sub New(ByVal color As String)
            Me.color = color
        End Sub

        Public Property Color As String
            Get
                Return color
            End Get
            Set(ByVal value As String)
                color = value
            End Set
        End Property

        Public Sub ShowData()
            Console.WriteLine("I am a door, my color is {0}.", color)
        End Sub
    End Class

    Class SmallApartment
        Inherits House

        Public Sub New()
            MyBase.New(50)
        End Sub

        Public Overrides Sub ShowData()
            Console.WriteLine("I am an apartment, my area is " & area & " m2")
        End Sub
    End Class

    Class Person
        Protected name As String
        Protected house As House

        Public Sub New()
            name = "Juan"
            house = New House(150)
        End Sub

        Public Sub New(ByVal name As String, ByVal house As House)
            Me.name = name
            Me.house = house
        End Sub

        Public Property Name As String
            Get
                Return name
            End Get
            Set(ByVal value As String)
                name = value
            End Set
        End Property

        Public Property House As House
            Get
                Return house
            End Get
            Set(ByVal value As House)
                house = value
            End Set
        End Property

        Public Sub ShowData()
            Console.WriteLine("My name is {0}.", name)
            house.ShowData()
            house.Door.ShowData()
        End Sub
    End Class

    Class TestHouse
        Private Shared Sub Main()
            Dim debug As Boolean = True
            Dim mySmallApartament As SmallApartment = New SmallApartment()
            Dim myPerson As Person = New Person()
            myPerson.Name = "Juan"
            myPerson.House = mySmallApartament
            myPerson.ShowData()
            If debug Then Console.ReadLine()
        End Sub
    End Class
End Namespace