C# :: Properly Create Game Objects?

I am making sims like game and right now I am trying to figure out how I will structure my objects. right now I am thinking to create a class called GameObject, the psuedo is below

public class GameObject {
name:String
width:int
height:int
}

This way I could create objects like bushes, trees, and buildings. But then I began to think. what if I wanted to create multiple buildings and trees of the same type ?? I would have to keep making instances of GameObject and giving it a new name and height and width. The properties would have to be the same values in order for me to duplicate one object. That seems a little tedious. Then I figure , maybe that isnt the right way to go. So I was thinking, I would have to extend GameObject like below

public class Tree extends GameObject{
birdHouse:Boolean
}
public class Building extends GameObject{

[code].....

Now this way I can create a class that has a method that loosely accept accepts any type that inherits GameObject.

Selector.loadObject(gObject:IGameObject);

Depending on what type it is (i.e tree, building, house) I can use a case statement to figure out which type it is and evaluate it accordingly.

I also created a Tile Class that will pass through the loadObject method. It also will be a child of the GameOject class. if the case statement finds that it is type Tile, it will highlight whatever Tile depending on what tile my mouse is over.

My second question is if a class inherits a class that implements a interface, is that class child class considered to be a IGameObject as well. or does it have to implement that interface directly. does all this sound like I am going in the right directions lol, as far as organization is concerned.