The price per sqm is an estimate of the house only, it doesn't include the garage, fence, gate and landscaping. The contractor usually base their quote on the specifications on the plan. I've seen 2 different approaches here, where 1 provides you with a breakdown of the labor and materials with a contingency, administration and contractor's mark up. The other is just plain labor and materials, where all the contractors costs are supposedly folded inside the labor and the contingency in the materials. Quotations for the fence and gates may be included if you like. So is landscaping.