# Using IfcOpenShell and pythonOCC to construct new geometry

[This article contains several snippets of source code for illustration purposes, the full source code can be downloaded at the bottom]

In this short exercise we are going to build on top the IfcOpenHouse model. It is one of the first IFC models entirely built using program code. It is a nice model, but it has a few shortcomings: for example, it does not define an IfcSpace instance that describes the interior space bounded by the walls and roof. In this exercise we are going to model the geometry of this space automatically from the geometry of the bounding elements and calculate the interior volume of the model.

*The IfcOpenHouse model as imported into a regular CAD application*