Labelling offers a fantastic opportunity to make building energy and CO₂ performance visible. Although initially for information only, raising awareness and disclosure is only the start. Given our addiction to high carbon lifestyles stoked by our growth-dependent economy, altruism or even fashion are unlikely to be enough to initiate sufficient actions to reduce emissions by the 60% from current levels by 2050 target IPCC scientists say is necessary to stabilise CO₂ levels in the atmosphere (let alone by the 85% necessary if the 'Contraction and Convergence' plan is adopted). Politicians hope for a new age of low carbon energy supplies and ultra efficient end use, implying hardly a murmur on the global economy as we undergo the transition. Other commentators forecast a need for draconian carbon rations. At the very least, unless energy prices rise considerably, it seems inevitable that labelling buildings will need to be followed up by some tangible reward for better performance, such as reduced rates of Property Tax. This could in turn provide the drivers - or even the 'tipping point' - for a radical improvement of the energy efficiency of existing and new buildings; and help to transform markets - as has already been demonstrated for electrical appliances.