I'm building a Patio and the workers gave me 1ft of extra room than what it says on the contract signed/agreed too. Can the company charge me extra for something I didn't ask for?

Typically, they cannot charge you for their error.  However, if you became aware of their error before completion, and did not notify the builder of their error, you may be held liable for the costs associated with the extra foot of space.   This is not intended to be legal advice, and is general in its nature.  No attorney-client relationship exists or is formed by this information.  Furthermore, this does not represent the views or opinions of LexisNexis or its affiliated companies.