This research project is about parametric design in architecture. More specifically, it focuses on the integration of expert information and digital simulation into a parametric modelling system for digitally fabricated wood constructions. While its practical applications are very specific, the underlying issues it proposes to work on are of a fundamental nature and have larger implications. This research project takes on the main shortcomings of today's parametric design systems, which can be summarized as a general lack of successful methods for design decision-support. These shortcomings have become especially pertinent in light of the recent implementation of the directive 2010/31/EU, which was adopted in order to strengthen the energy performance requirements on buildings. Tools that would allow designers to deal creatively with these more complex requirements as part of a normal design process are simply not available today. Current Building Information Modeling (BIM) systems not only use simple physical simulation models, they also lack some fundamental capabilities for design decision support. One main unsolved problem is that the integration of simulation systems is so far done in a purely one-directional way. We propose to develop an augmented parametric modelling environment with an open, modular structure that can provide real-time design feedback and suggestions for improvements and optimizations based on a variety of design criteria that define a building's performance. To that end we will also explore ways in which more accurate simulation methods can be integrated in a bidirectional way into the parametric system. To investigate these issues in depth we will concentrate on just one particularly interesting type of wood construction: cross-laminated timber (CLT). CLT is a material with very positive characteristics in terms of energy-efficiency and sustainability and - as we have already seen in an earlier FWF project conducted at our institute (FWF grant L695), - it has large potential for customization through digital fabrication. The project proposes to develop what we refer to as "Augmented Parametrics": a new type of parametric program that supports performance-based modelling based on detailed physical simulation modules. By focusing just on one single construction material we can also take construction issues such as jointing into account, while also providing easy access to high level optimization approaches (e.g. genetic algorithms). The project's ambition is to lay the conceptual and methodological groundwork for such augmented parametric systems and to test it with practical applications for a particular type of construction and simulation in a proof-of-concept manner.