I have two houses with tado products and one e-mail address how should I set up?
You need one tado account per home, multiples homes are not supported yet. You can find this development suggestion in our Suggestions, Ideas and Improvements section, were some other users proposed it, please vote for it if you are interested.
If you are an iOS user, HomeKit allows having several Homes in the Home app. You can have each one of your tadoº systems linked to each one of these homes in the same Home app. Bear in mind that HomeKit requires the presence of an Apple TV in the system to allow remote access.
Don't hold your breath. It was on their upcoming features list in 2017..