All new and renovated buildings in Spain must now have solar panels, Reuters reports.  The code will come into force fully next March but the energy saving element was implemented on Sept. 29.

New homes have to be equipped with solar panels to provide between 30 and 70 percent of their hot water and commercial buildings have to have photovoltaic panels to generate electricity.

“The new standards will bring energy savings of 30 to 40 percent for each building and a reduction of carbon dioxide (CO2) emissions from energy consumption of 40 to 55 percent,” the Environment and Housing Ministries said in a joint statement.

The construction lobby Asprima estimates that the new requirements will increase building costs by between 8 and 12 percent. Proponents say that the extra cost was 1 percent, which would be offset by the energy savings achieved.