The document discusses national programs in the Netherlands to upgrade energy efficiency in existing buildings. It outlines the Dutch energy transition plan to achieve sustainable energy by 2050 through seven themes, including energy in the built environment. The target for buildings is energy neutrality for new buildings by 2020 and halving the primary energy demand of the existing building stock by 2030. Key programs discussed are "More With Less" to reduce energy demand in 3 million homes/buildings by 30% and innovation projects to demonstrate 45% energy efficiency improvements in apartment renovations. The biggest challenges are faster adoption of proven innovations and boosting collaboration across the building sector.