After a period where the Internet was exclusively filled with content, the present efforts are moving towards services, which handle the raw information to create value from it. Therefore labors to create a wide collection of agent-based services are being perfomed in several projects, such as Agentcities does. In this work we present an architecture for agent platforms named a-Buildings. The aim of the proposed architecture is to ease the creation, installation, search and management of agent-mediated services and the share of resources among services. To do so the a-Buildings architecture creates a new level of abstraction on top of the standard FIPA agent platform specification. Basically, an a-Building is a service-oriented platform which offers a set of low level services to the agents it hosts. We define low level services as those required services that are neccesary to create more complex high level composed services.