A long-standing goal of the Zero Carbon Hub is to work with experts across the house building sector to recommend energy and carbon standards for Zero Carbon new homes which are both stretching and cost-effective. For obvious reasons, understanding the costs associated with building Zero Carbon homes has been, and remains, a critical issue for stakeholders. It therefore continues to be a core part of the Hub’s programme of work. The analysis contained in this report, produced for the Hub by Sweett Group, provides an updated assessment of these costs. It reflects, for example, the significant reductions in installed solar PV costs seen in recent years. What the new analysis shows is that, in many of the scenarios considered, the cost of building to the proposed Zero Carbon Standard has roughly halved since we last published cost estimates in 2011. Furthermore, our projections suggest that costs may continue to fall between 2014 and 2020.