Hi, we are designing a new build that will be located at the NSW south coast. The block slopes to the front at the north and the design concept is a garage under layout with the living areas upstairs. A full width verandah lies over the garage and forms a covered area to the north east. The upper level will be a suspended slab with R2 insulation underneath to make use of the solar passive orientation with 2 x 3.2m sliding doors facing north. Living areas will be tiled. Given that the slab extends outside over the garage and the covered area, what are people’s thoughts about heat loss/gain in the house from having a continuous slab exposed to the elements? The builders we have spoken to say it will not be an issue because it is a relatively temperate climate (mean 25C max in summer and mean min about 5C in winter). We could thermally break the slab where it exits from under the northern wall of the upper level but that will add cost and likely pose a water leakage issue for the garage under.