As the World Chef game progresses you are able to unlock more land to allow you to expand your restaurant. First though, you need to clear land of trees, rocks and shrubs. This is done using tools (chainsaws) which you will collect from your guests who randomly give you gifts when you collect their payment, but you can also buy them from the Social Market.
Once you have cleared the land you are able to buy it. Previous versions of the game required you to pay coins for land but now you need to have the required number of tools, which increases by one each time you unlock a piece of land.
One you have completed your land expansion you are free to extend your restaurant. Read our guide to placing walls and floors to learn more.