The Roof - Thatch or Tiles?

I say thatch.
Thatch is made from straw or water reed. It is bundled together to make the roof.

Thatch is a renewable resource. Straw can be used from farmers' fields.
As it comes from plants, thatch actually uses up carbon dioxide when it grows.

I say tiles.
We could never grow enough thatch for all the houses we need to build and it takes too long to thatch a roof.

Tiles are safer. They can't catch fire like a thatched roof can.
Tiles are easy to make and not expensive. Thatch costs a lot. Some comes from Norfolk in England, but lots of the water reed used for thatching comes from places as far away as Turkey or even China.
Ask your teacher
... if you can build your own roof to find out which shapes and materials are best.