d) Encouraging and supporting local community and popular initiatives that work towards the resolution of the respective housing problems and foster the formation of housing and self-building cooperatives. 3. The state shall adopt a policy that works towards the establishment of a rental system which is compatible with family incomes and provides access to individual housing. 4. The state, the autonomous regions and local authorities shall define the rules governing the occupancy, use and transformation of urban land, particularly by means of planning instruments and within the overall framework of the laws concerning town and country planning and urbanism, and shall expropriate land that proves necessary to the fulfilment of public-interest urbanisation goals. 5. The participation of the interested parties in the drawing up of urban planning instruments and any other physical town and country planning instruments is guaranteed. Article 66 (Environment and quality of life) 1. Everyone has the right to a healthy and ecologically balanced human living environment and the duty to defend it. 2. In order to ensure the right to the environment within an overall framework of sustainable development, the state, acting via appropriate bodies and with the involvement and participation of citizens, is charged with: a) Preventing and controlling pollution and its effects and the harmful forms of erosion; b) Conducting and promoting town and country planning with a view to a correct location of activities, balanced social and economic development and the enhancement of the landscape; c) Creating and developing natural and recreational reserves and parks and classifying and protecting landscapes and places, in such a way as to guarantee the conservation of nature and the preservation of cultural values and assets that are of historic or artistic interest; d) Promoting the rational use of natural resources, while safeguarding their ability to renew themselves and ecological stability, with respect for the principle of inter-generational solidarity; e) In cooperation with local authorities, promoting the environmental quality of rural settlements and urban life, particularly on the architectural level and as regards the protection of historic zones; f) Promoting the integration of environmental objectives into the various policies with a sectoral scope; g) Promoting environmental education and respect for environmental values and assets; h) Ensuring that the fiscal policy renders development compatible with the protection of the environment and the quality of life. Article 67 (Family) 1. As a fundamental element in society, the family has the right to protection by society and the state and to the effective implementation of all the conditions needed to enable family members to achieve personal fulfilment.