Design plays a central role in a range of subjects at different educational levels. Students have to acquire the knowledge necessary for the execution of tasks that enable them to construct an artefact or model that can be tested by simulation and that satisfies some requirements and verifies some constraints. They achieve this by means of a design process. In some design domains, there is a lack of teaching tools from a learner-centred perspective. Moreover, when these domains are complex, the design problems that the students have to solve during their learning process require the design activity to be carried out in group. In response to this situation, we have developed a design model and a collaborative learning method. Using this conceptual framework, we have built a collaborative environment for the learning of domotical design by means of complex problem solving, with an emphasis on synchronous collaboration for work distribution, discussion, design in shared surfaces and simulation. This environment has already been evaluated and used in real teaching experiences.