Think of it this way. Your allowed 55% give or take builing envelope on the site. Anything open on two or more sides is classed as open space ie alfresco, portico, carport etc.
Total coverage is "Proportion of total site area covered by all buildings and structures roofed with impervious materials" i.e. total roofed area including eaves.
Counts toward site coverage
House
Attached Garage
Storage Room
Garden Shed?
Covered Parking and walkways
Outbuildings
Does not count
Patios/Verandahs *
Alfrescos*
Pergolas
Paving and Footpaths
Driveways
Building Eaves
uncovered driveways and car parking
*unenclosed on at least 2 sides and covering no more than 10 per cent of the site area or 50m2 whichever is the lesser .