Urban heritage policies are rarely assessed on a regular or continuous basis. Formal indicator guidelines and scholarly work address some possible evaluation methods for urban heritage policies, but a gap exists between the generalized work and limited on-site implementation. Spatial and non-spatial datasets should contribute to our understanding and refinement of such policies. Yet, in practice, data and the proper assessment mechanisms are often lacking. This research presents Tel Aviv’s 2650b preservation plan as a case study to explore possible assessment methods of policy effectiveness. Tel Aviv is the second-largest city in Israel. In 2003 UNESCO declared the White City of Tel Aviv, the center-city area, a World Heritage Site (WHS). UNESCO based the designation on an outstanding synthesis of the Modern architecture movement and an outstanding example of new town planning of the 20th century. Municipal plan 2650b was enacted in 2008 and is linked to the WHS, protecting modern architecture and mainly focusing on the center-city area. The Plan classifies properties into two preservation levels and three architectural styles. The city’s online building archive facilitates analysis and evaluation of plan 2650b. The Plan has been in place for over a decade, during which no data-driven comprehensive evaluation or monitoring processes occurred. Relying upon Kitchin’s definition of effectiveness, in the context of urban indicators, as “whether goals and objectives are being met – doing the right things,” this research asks: what factors correlate with the effectiveness of Tel Aviv’s preservation plan? Three sub-questions lead the research: Are the Plan’s goals being met? Are they being met in the same way throughout the Plan area? And, how, if at all, are pre-existing characteristics of the properties addressed by the Plan? The study assesses the outlined goals and presents a roadmap for constructing indicators and spatial analysis for a specific policy. The study approach uses an author-created property-level database to assess proposed customized indicators and run spatial analysis. It finds that the prevalence of preservation varies across space, among architectural types, and between the two preservation-restriction levels. In particular, the Plan is relatively less effective at preserving Modernist buildings. These findings reveal the inconsistency of the Plan at protecting the Modernist architecture at the core of the global designation. The results stress the need for data collection, setting numeric objectives, monitoring plan outcomes, and potential future research to realign incentives with preservation goals.