The use of thermoelectricity in buildings represents a significant alternative for indoor thermal comfort necessities avoiding the use of refrigerants. One of the possible application options of this technology is the integration of thermoelectric modules in a building facade. Even though several studies have examined the technology for this application during the last years, the consideration of the system as a constructive element of a building has been a secondary issue so far. In this study, a detailed description of the design and construction of a Ventilated Active Thermoelectric Envelope (VATE) module is presented. A VATE is an industrial-scale modular prototype designed to be installed in the building facade and thought to be an alternative solution for heating and cooling in Net Zero Energy Buildings. Moreover, the prototype module has been tested to assess its heat power and performance in heating mode. The results show that the heating power varies between 66.8 and 273.6 W, depending on the input voltage tested, and the COP of the whole system decreases from 2.1 to 1.0 as the voltage increases. The design of this module prototype can be considered as a first approach towards the solution of designing VATEs that can be replicated. This is a required step for the possible industrialization and implementation of the system in the future. (C) 2018 Elsevier B.V. All rights reserved.