Here in the UK, 30% of the cost of a new house build is the foundations, the excavation, and then filling of a hole in the ground with many tons of concrete. I find it baffling how little innovation in construction has been adopted by the house building industry here. Light weight timber frame construction on pile foundations would massively reduce both the carbon footprint of the build and the cost.
When I have made these arguments before, people often respond that our heavy weight brick construction is better as it withstands the weather more, and will last longer. But with modern materials (or good old traditional maintenance) thats just not true, a timber frame house can last hundreds of years.
Finally, it's not just the carbon emissions from cement manufacturing that worries me. I live about 3 miles from a cement factory, and the amount of dust that it puts out is staggering. If I clean my car, within two days it's covered in a thin layer of dust thats locally attributed to the factory. I can't imagine thats good for our health!