UCL DEPARTMENT OF CIVIL, ENVIRONMENTAL & GEOMATIC ENGINEERING
GREEN BIM
FOR UCL’S CHADWICK BUILDING
UCL DEPARTMENT OF CIVIL, ENVIRONMENTAL & GEOMATIC ENGINEERING
The 10-week work involved:
The Green BIM project has 3D reality capture, surveying, 3D
initiated the analysis of UCL’s modelling, comfort analysis and
Chadwick Building, a Grade I thermal modelling.
listed building, in terms of
environmental performance and 3D REALITY CAPTURE
sustainability. In summer 2012 Using a 3D laser scanner
an initial 3D BIM (Building the spatial geometry of the
Information
Model)
was Chadwick’s rooms, staircases
created and issues such as space and corridors was captured in
utilisation and user comfort were the form of point clouds. These
investigated. Once completed, were used as a guide to draw
the 3D digital model can act as the building elements in the
a ‘living lab’ allowing members model. Point clouds are also a
of the multi-disciplinary CEGE visual aid for thermal modelling,
department to carry out further which requires knowledge of
research and use the model for the locations and dimensions of
windows and lights. Scanning the
simulations.
The initial phase of this project whole department took 3 weeks
included gathering information, and produced nearly 350 point
collecting metering data and clouds!
engaging
personnel
to
understand the listed building SURVEYING
Accuracy was a very imporbuilt in 1894. It also aimed to
integrate the knowledge of tant factor when producing the
CEGE and other areas of model. The point clouds are
UCL to provide work experi- accurate within themselves but
ence for UCL students whilst their locations relative to each
exploring new technologies and other need to be defined. These
locations were obtained through
methodologies.
surveying using a robotic total
station. The total station used
provided visuals of points
captured on its interface.
The survey data provides a
framework that places point
clouds in the correct positions,
providing reliability to the geometry of the full data set.
Top: Using the total station and laser scanner
Right: Combined point clouds for staircase
Top: Sensor data from room 217 on light
intensity temperature and relative humidity
A ‘LIVING LAB’
3D MODELLING
Once the set of data was
obtained,
AutoDesk
Revit
software was used to process the data and create the BIM
model of the Chadwick Building.
Walls, windows, doors, floors,
ceilings, lighting and equipment
such as computers were drawn in
REVIT as parametric objects
using the 3D reality capture as
a guide. Data was attributed
to these elements turning the
3D drawing into an intelligent
model. Some examples of attributes are material properties
of the building envelope, energy
consumption
of
electrical
equipment or type of lighting.
GREEN BIM FOR UCL’S CHADWICK BUILDING
COMFORT ANALYSIS
Sensors
monitoring
the
temperature, light intensity and
relative humidity were placed
in 20 rooms, with an aim to
represent the variation in
working
conditions
across
a range of room types. The
sensors provided a reliable and
accurate data set which was used
to validate thermal modelling
software. This data set can later
be integrated into the complete
Chadwick Green BIM. A thermal
imaging camera was used in the
20 rooms to assess hot and cold
spots. The validity of the camera
was confirmed by the sensor’s
data.
Furthermore, an anemometer
was used to provide information on the speed, volumetric
flow rate and temperature of air
entering and exiting the vents. In
the 20 rooms monitored, only 3
vents provided enough air at a
suitable temperature.
Top: Thermal image and photograph of a vent
in room GM16.
Right: Final BIM Model of room 223
THERMAL MODELLING
The BIM was used in
conjunction with building energy
analysis tools, such as AutoDesk
Ecotect , to simulate air and
temperature flow. Simulations
were run on a stand-alone model
of classroom G08 and a model
of G08 within the ground floor
to see how surrounding rooms
affect the results. The second
m¬odel most closely matched
the sensor data recorded for
G08. The whole building should
be constructed and modelled
for maximum reliability and
accuracy.
INITIAL FINDINGS
The user comfort and thermal modelling confirmed the
poor conditions in Chadwick and besides the temperature and ventilation findings,
these are other initial findings:
• The project found that the
current CAD drawings are
incorrect in terms of scale and
some room locations when compared with the actual state of the
building. There were also differences between room labels in the
CAD and in reality. When building the 3D model, the structural
elements such door frames and
windows were completely inconsistent across adjacent rooms.
• Investigations into equipment
and appliances that were used
and space utilisation across the
department were conducted. A
brief analysis yielded results such
as: 44 % of personal offices have
kettles or coffee machines; there
is a lower density of kettles on
the second floor due to presence
of a communal coffee making
area. The data on user behaviour
suggests there is still work to do
regarding behaviour change and
user awareness in the department.
Top: Basic model of room G08 in AutoDesk
Ecotect ready for thermal modeling
UCL DEPARTMENT OF CIVIL, ENVIRONMENTAL & GEOMATIC ENGINEERING
NEXT STEPS
The next step is to complete and refine the structural and MEP systems in the Chadwick BIM. The
model can then be used for whole-building simulations as a basis for recommendations on how to
improve sustainability in the Chadwick Building.
POSSIBLE APPLICATIONS
* Further comfort analysis and thermal modelling
* Facilities Management- The BIM could be used to improve health and safety, fire safety and
security systems. Ideally the 3D visual model will be able
to be integrated with maintenance database
systems so they are more user friendly. Asset
management
* Accessibility modelling- producing
software in BIM that can identify accessibility routes
* Investigating and simulating ways to improve
sustainability and reduce energy consumption:
* Implementation of passive cooling and heating systems to reduce need for mechanical ventilation
* Embedding energy use and total heat generated to
equipment and lighting and testing the effects of
retrofitting these
* Optimising use of daylight in the building
* Structural Modelling
* Acoustic Modelling
* Modelling water management
For more informattion on
the Green BIM please contact
Dietmar Backes
d.backes@ucl.ac.uk