This document provides guidance for the development and use of the Reference Architecture within the Human Exposome Assessment Platform (HEAP). This document describes the technical architecture, data and metadata flow and means for accessing data in the platform. It informs of the tools required, the nature of work to be carried out and the required set of components or contributors to be involved in developing the platform. The architecture presented in this document and its implementation are coordinated within the Secure Infrastructure for Big Data Work Package (WP10) and its aim is to develop an IaaS (Infrastructure as a Service) platform for the HEAP Information Commons with the main features storing and managing sensitive data. The platform will provide secure data storage in a cloud environment and allow streaming of remote data for processing through a secure data access mechanism.