Optional property construction for ThermalBoundary

Created by: JoachimBenner

While developping an interface of the Energy ADE to the commercial Energy Simulation System we are using, we got a problem. Our system needs the material/construction properties and the area of the complete Thermal Boundary (i.e. the area including windows), and directly related with the Thermal Boundary the material properties and areas of the corresponding Openings (windows or doors), The area of Openings is always regarded as difference areas, which need to be subtracted from the total area of the Thermal Boundary.

Because gxXML models openings in a similar way, I expect the other simulation systems implement a similar logics. However, the actual version 0.7.0. of the Energy ADE is not very good suited to represent a hierarcy of Thermal Boundaries and corresponding Openings, because all ThermalComponents are on the same level, regardless whether they represent opaque or transparent parts of the Thermal Boundary.

I therefore propose to allow a Thermal Boundary optionally to be related with a Construction. This would introduce much more flexibility into our data model.