Smart buildings is a common application for both Internet of Things (IoT) devices and cloud services. Recently cloud service providers such as Amazon, Google and Microsoft have started to offer IoT cloud platforms which consist of a class of services that provide a base for cloud applications utilized by IoT devices. However, there are many different providers of IoT cloud platforms and selecting one for an IoT solution for a smart building is difficult. In this thesis two IoT cloud platforms are evaluated in the context of smart buildings as part of an assignment given by Sigma Lundinova. To evaluate the IoT cloud platforms a common smart building scenario is realized by implementing a prototype using two different IoT cloud platforms. The development process makes it possible to evaluate how well the platforms support the development of the system that the scenario describes. The evaluation is based on information and experience from the process of developing the system using the IoT cloud platforms. The evaluation can be used as a guidance when selecting IoT cloud platform for an IoT solution intended for a smart building.