Preserving enough? A randomised controlled trial approach to determine relevant urban planning regulations for small touristic towns – A case of Chiloé, Chile

Rapid tourism growth in small towns of unique cultural heritage often leads to sudden building renovation and infrastructure expansion, which can compromise their attractiveness. The typically under-resourced urban planning departments of the Global South face a complicated task in establishing planning regulations that can preserve a town's identity while accommodating these rapid transformations. This requires a delicate regulatory equilibrium – too restrictive an urban plan could hinder investment and local growth, while a less restricted approach risks destroying a town's heritage, identity, and touristic appeal. This study presents a randomised controlled trial in which residents and tourists rate a town's visual identity using photo simulations of 27 different planning regulation scenarios, drawing from a real-life conservation plan on the island of Chiloé (Chile). We test the effectiveness of this method for identifying which building regulations are relevant for preserving a town's identity. This low-cost and rapidly implemented method may complement the work of urban planners in setting the regulatory framework for conservation.