society and end user costs. The final decisions in relation to the application and use of heating that issue from the district-specific implementation plans will be included in the RES 2.0. The parties have agreed the following: a. Municipalities will draw up a transition vision for heat in consultation with stakeholders by the end of 2021 in which they will establish the timetable for a step-by-step approach to phasing out natural gas (with insulation potentially constituting one step, provided it is part of the district-oriented approach to transitioning away from natural gas). The potential alternative energy infrastructures will be set out for districts planned for transition ahead of 2030 and municipal authorities will provide insight into the social costs and benefits and the integral costs for the end users. In the transition visions for heat, municipalities will be programming as much as possible based on the lowest social costs and costs for the end user. b. The transition visions for heat are essential to achieving a low-carbon built environment. In order to make these transition visions a reality, homes and other buildings will be insulated and rendered natural gas-free or ready to become natural gas-free in consultation with residents and building owners. In the context of the district-oriented approach, the PBL has estimated that 1.07 million homes and other buildings can be rendered natural gas-free in the period up to 2030. To ensure that sufficient savings are made, municipalities are drawing up plans to improve the sustainability of 1.5 million homes and other buildings between 2022 and 2030 with a start-up period from 2019- 2021. The parties will agree upon a step-by-step approach in which insulation and other carbon-saving measures also explicitly form a part of the district-oriented approach. The parties will collaborate on alleviating any barriers or obstacles to realising the transition visions for heat. c. Municipalities will initially be reviewing their transition vision for heat every five years. By 2022, the VNG and the government will assess whether this review and update period of five years is suitable. This will also align with the knowledge and learning programme of the Programme for Natural Gas-Free Districts (PAW). d. Municipalities, in consultation with the relevant stakeholders, will determine the schedule of the step-by-step approach to phasing out