Construction and operation of buildings has an important environmental impact. The most widely used construction material is concrete; which is heavy, has rather high embedded energy, strongly draws upon non-renewable resources, is challenging to re-use, and exhibits rather poor building-physical properties with regard to thermal insulation and storage capacity, acoustic insulation. Last but not least, the concrete types used today in mid-size building construction are essentially far too good from a structural point of view. Mixes of concrete with wood components, so-called wood-concrete compounds (WCC), may be one of the answers to the challenge of a more sustainable evolution of concrete-based construction. They substitute some of the non-renewable parts (gravel, sand) of the concrete composition with renewable ones. From an environmental and economic point of view, by-products of the wood utilization chain shall be used with the objective to create a light-weight, pourable, self-compacting, cheap and “greener” construction material that has further benefits with regard to building-physical properties and might even be partially recyclable. From a sustainability point of view, WCC should rather be used in composite action with timber than be reinforced with reinforcing steel. Developing such “greener” types of concrete may thus considerably contribute to a sustainable development of mid-size building construction. The challenge, however, is finding appropriate WCC composition that solves the problem of delayed hardening of concrete due to the natural sugar embedded in wood.