When selecting a good efficency intervention, people is often obliged to respect very complex rules and costs. Simple effective solutions are often considered illegal, while other more complex are heavily subsidized. Examples: here to insulate a building you are obliged to about 14cm of insulation thickness plus the wall. Simple and natural materials (wood,etc.) may require certifications even if their properties are intrinsinc. Open the market! Increase the professional's role and authority.