The form you need is at the bottom of this page

READ THIS INFORMATION FIRST, BEFORE YOU DOWNLOAD THE FORM!

Not submitting all required information will DELAY your project!

Items you will need to submit:

       A [site plan] or [survey] that has the location of the extension drawn on it
       What materials the extension will be made of
 

Double check the following:

       The extension must be outside of any side or rear [setbacks]
       The extension must be outside of any [utility easements]