This paper analyzes the degree of climate policy integration (CPI) in Germany’s building policy. The basic assumption of CPI is that the cross-sectoral and multi-level challenge of climate change necessitates the integration of climate concerns into non-environmental policy fields (horizontally) and across different levels of governance (vertically). There are at least three dimensions in which CPI can be analyzed, namely a conceptual, a procedural, and an output/outcome dimension. We use this distinction and analyze the current status of CPI in Germany’s building policy, an area highly relevant for climate change mitigation. In all three dimensions, CPI appears to be at a fairly low level, leaving much room for improvement in terms of prioritization, coordination, and coherence. It seems as if political commitment to climate change mitigation has a rather low impact on everyday policymaking, i.e. when decisions on trade-offs, resources, and reallocations have to be made. In the absence of a comprehensive strategy, current German building policy does not reflect the need for coherent and long-term climate policymaking. What is the role of federalism in this regard? In section 2, we outline that federalism might impact both positively and negatively on the prospects of CPI, and that there is no uniform relationship between the two. In the specific case of building policy, a number of negative effects of federalism – incoherence, veto players, enforcement deficits – seem to materialize. Even though coordination between federal and Länder level is deemed necessary, reality shows that it happens only to a very limited extent. The Länder partly opposing more ambitious policies, a stronger integration and are varying considerably regarding the implementation of federal policies. On the other hand, potential advantages from federalism for CPI are limited in the field of building policy. Baden-Wuerttemberg’s pioneering role in setting standards for renewable heating systems certainly inspired federal legislation, but so far that is mainly restricted to new constructions. The lacking horizontal CPI across departments in particular as well as the lack of coordination across levels of decision making leads to an argument for more and better coordination between all actors involved, be they federal or state actors. Coordination needs to be firmly embedded in the whole policy cycle, starting with joint target-setting, continuing with agreement on adequate policy instruments, and concluding with an evaluation of effects. Strategic capacities, e.g. dedicated institutions or budgets would be needed to maintain the topic on the agenda as an issue of high priority even after changes in government. The finding however, indicates that the low hanging fruits of energy demand and efficiency have not received similar attention as the supply of (renewable) energy.