Get the best Granny Flat in Gregory Hills, then contact Santolo Building Design. Santolo Building Designs is an Accredited Building Design company in Leppington, NSW, that helps homeowners design their dream home. Designing your dream home should be a breeze, not a struggle. Allow the team at Santolo to manage the design process of your home so you don’t have to stress about complicated applications and paperwork. From Concept design to gathering necessary approvals and signoffs, our team of building design experts strives to bring your dream home to life while making life easier.