Do rooftop home gardens regulate temperature? Insights on indoor heat regulation and thermal comfort in Bangalore

Urban Farm DB summary

As urban heat increasingly affects liveability, labour productivity and human health, nature-based solutions such as green roofs, increased urban tree cover and dedicated park space have been proposed to adapt to rising urban heat, but the literature has paid relatively little attention to how smaller urban green spaces — fragmented urban greenery and rooftop home gardens — contribute to hyperlocal temperature regulation. This study examined whether rooftop home gardens in Bangalore, India, regulate indoor temperature and provide thermal comfort, drawing on perception-based data from household surveys and in-depth interviews alongside modelled scenario data covering different types of rooftop home gardens. People generally perceived thermal comfort in rooms directly below rooftop farms/gardens, and reported air-conditioner use declined after starting rooftop gardening. Modelling across seven scenarios, from no green cover to complete (100%) soil-bed cover, showed heat reduction benefits ranging from 1.5°C to 14°C depending on foliage type, density and extent of green cover; because most rooftops serve multiple purposes, the study identifies a more realistic temperature reduction of 1.5°C to 3°C, corresponding to a scenario with 50% of the roof covered in dense foliage.