Not necessarily needs to be changed, but I think you will find that you will want to do things like make it bigger, add a second level or change the shape. If you look in the galleries (the little camera icon) you will see hundreds of examples of cages that will give you many ideas.
You can find links to the materials and instructions on the
home page. Most of us in the US get our grids at Target. Here is what the package looks like:
One package is enough for a minimum cage but if you get 2 or 3, you can use any extras for a floor time pen. One box is $15 normally but sometimes they have them on sale for $13.
The coroplast can be found at most sign shops. I pay $10 for a 4 ft by 8 ft sheet but I have to get 2 at a time since the place I get it from has a $20 minimum purchase.
Here is a my thread that I posted the last time I redesigned my cage.
http://www.guineapigcages.com/forum/...pictorial.html
This took me about 2-3 hours. As you can see in the pictures I just did this in September and I am already looking at what changes I can/will make.