The guys from MBC have poured the slab this morning using a low cement mix of concrete with a much lower carbon footprint. 50% of the cement is replaced with fly ash- a waste product from blast furnaces. It getting used more commonly now due to its better environmental credentials and resilience. The pipes showing are for underfloor heating, which shouldn’t be needed much due to the high levels of insulation we will be putting in. The slab will act as a heat store as it’s surrounded by insulation.