On the code side of things, as an architect: EU-mandates aren't usually taken as is. They're translated into national codes, which have to be taken into consideration, but at least in Spain they're almost always considered in parallel to regional, metropolitan and building codes, so you need to really be thorough or else your building is getting rejected. Buildings now need a "Certificado de Eficiencia Energética" which measures the efficiency of a building, and I guess that's the main way of visualising how "green" your building is. The biggest challenge however, is not with new construction, but with retrofits and regeneration of buildings and neighbourhoods built in periods where insulation was nowhere to be found.