Given the fact that the residential sector contributes significantly (directly and indirectly) to the total emissions of greenhouse gases, the government of Mexico decided to implement the first global plan of National Appropriate Mitigation Actions (NAMA). This program promotes the design of efficient homes based on an energy comprehensive housing approach, since it is more cost-effective and allows greater reductions than other schemes whereby only specific efficiency technologies are applied in homes.

To achieve this, the quality of the construction sector had to be improved; raising energy efficiency standards for housing, meaning this would bring higher costs to social housing developers. To address this problem, the ECOCASA program ( ME-L1121 ) developed an arrangement whereby the use of architectural and construction techniques, provide greater flexibility for the implementation of energy efficiency in housing. Financing had two components. The first one US $50 mi of concessional Clean Technology Fund (CTF) resources and €80mi from the German KFW Bank, for the construction of sustainable houses. The second component financed the origination of green mortgages, adding US $50 mi from the IDB's ordinary capital.

CTF concessional resources have also funded various technical cooperation activities that have been crucial in the implementation of the program in order to i) improve the existing simulation models that determine the sustainability of each project; ii) design and implement a monitoring and evaluation tool; iii) and finally for dissemination, knowledge, management, and training.

In conclusion, the program ECOCASA allows the supply of environmentally efficient housing in an affordable way, while providing the expertise to developers so they can negotiate with suppliers and authorities, eco-technics best prices and tariff quotas.

With the results of ECOCASA there will be indicators to negotiate in the future a conversion of consumer subsidies for upfront subsidies for energetic and water eco-technologies, as well as raise awareness in society on the optimal use of resources. To date, the program has been a success. At the end of June 2015 it has financed 12,756 housing units, of the 27,600 intended in the program.

ECOCASA and its projects have won several awards at international and national level, including: