In the past decade, research in Internet of Things and related technologies such as Ubiquitous Computing has fueled the development of Smart Spaces. Smart space does not just mean interconnection of different devices in our surroundings but an environment where the devices respond to human behavior and needs. To achieve this vision, services that are based on user’s intents and their high-level goals should be provided. However, existing works mostly focus on providing context-awareness based services. In the past, smart space developers focused on providing technology-centric solutions but this approach failed to achieve wider market adoption of products as users either did not want the solutions at first place or they just could not understand how it worked. Therefore, researchers and smart space developers have now shifted towards the user-centric approach for developing smart spaces. It is non-trivial to develop user-centric smart spaces as developers have to consider factors such as user requirements, behavior etc. apart from usual technical challenges. In this work, we take a comprehensive look at the challenges in developing user-centric smart spaces for two different smart space scenarios: Smart Home and Smart Shopping. We give four user-centric criteria to compare these two smart spaces. At the end, we also provide some future research directions for developing Smart Spaces.