Abstract:
Computerised systems have been developed to simulate the
dynamic thermal performance of a building over a period of
time, against a given weather pattern, with the aim of
predicting the environmental and energy performance of the
building. The usage of these systems has been limited, however
due to the difficulty in describing the problem to be simulated to
the system, and in interacting with the system. In particular
the geometrical form of a building can be very tedious to input.
This thesis considers the graphical creation of a building model
for environmental analysis, such that the necessary
geometrical data can be automatically derived and input into the
analysis. Current geometrical modelling techniques and the use
of CAD in building design are considered. The geometrical and
topological modelling requirements for the building model are
established, and a data structure is derived and checked for
sufficiency.
A possible modelling method is described for simple 21/2
dimensional buildings, and uses the property that the floor plan
of a building can be represented by a planar graph. The
necessary extensions to the modelling method are considered to
allow more complex 3 dimensional forms to be created. The
assignment of attributes to the model, necessary for the thermal
analysis, is also included.
Details arc given of the functionality of a user interface, using
an implementation of this modelling method. This includes a
description of the interaction to create the model, and the
graphical displays that are generated. This modelling method
has also been used in the development of an interface to an
architectural CAD system, such that the necessary building data
can be transferred for analysis.