Public Class Form1
    Private WithEvents mHaus As New Haus
 
    Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles CheckBox1.CheckedChanged
        mHaus.Raum1.Offen = CheckBox1.Checked
    End Sub
 
    Private Sub Raum1_Offen(ByVal name As String) Handles mHaus.TuerOffen
        Debug.WriteLine(name & " geöffnet")
    End Sub
End Class
 
 
Public Class Haus
    Private WithEvents mRaum1 As New Raum("Bad")
 
    Public Property Raum1() As Raum
        Get
            Return mRaum1
        End Get
        Set(ByVal value As Raum)
            mRaum1 = value
        End Set
    End Property
 
    Public Event TuerOffen(ByVal name As String)
    Private Sub Weiterleitung(ByVal name As String) Handles mRaum1.TuerOffen
        RaiseEvent TuerOffen(name)
    End Sub
End Class
 
 
Public Class Raum
    Public Event TuerOffen(ByVal name As String)
    Private mOffen As Boolean = False
    Private mName As String
 
    Public Property Offen() As Boolean
        Get
            Return mOffen
        End Get
        Set(ByVal value As Boolean)
            If value = True And mOffen = False Then
                RaiseEvent TuerOffen(mName)
            End If
            mOffen = value
        End Set
    End Property
 
    Public Sub New(ByVal name As String)
        mName = name
    End Sub
End Class