The document discusses the progressive use of Building Information Modeling (BIM) for holistic energy renovations, emphasizing its benefits such as lower costs, faster delivery, and reduced emissions. It outlines a methodology for energy renovation, focusing on information requirements, decision-making data, and case studies, particularly one involving an office building in Slovenia. Key results indicate significant energy savings and improvements in project management through enhanced data collection and analysis.

1. Progressive approach using BIM for
holistic energy renovation
Gašper Stegnar1, Tomo Cerovšek2
1Jožef Stefan Institute
2Faculty of civil and geodetic engineering, University of Ljubljana
Ljubljana, SLOVENIA

2. Why BIM?
• 33% LOWER COSTS: reduction in the initial costs of construction
and the whole life cost of built assets
• 50% FASTER DELIVERY: reduction in the overall time, from
inception to completion, for newbuild and refurbished assets
• 50% LOWER EMISSIONS: reduction in greenhouse gas
emissions in the built environment
• 50% IMPROVEMENTS IN EXPORTS: reduction in the trade
gap between total exports and total imports for construction products and
materials

3. What is BIM? Hint: It‘s not a 3D model.
The process of generating and managing building data during
its life cycle. Typically it uses three‐dimensional, real‐time,
dynamic building modeling software to increase productivity in
building design and construction.
The process produces the Building Information Model, which
encompasses building geometry, spatial relationships,
geographic information, and quantities as well as properties of
building components.
BIM as lifecycle BIM Maturity Level And Processes

4. Focus of work
• Energy renovation of office buildings.
• Inefficient building design that result in increase of
investment costs, design and planning errors and
construction delays.
• Prediction of energy consumption after the energy
renovation.
• Sustainability assessment of building with already
acquired data.

5. Multidisciplinary field of work
• Building design
• Sustainability assessment
• BIM
• Energy performance calculation
Source: https://csengineermag.com/article/what-does-bim-mean-for-civil-engineers/

6. The aim of the work
The focus is on the information requirements for progressive BIM
methodology in holistic energy renovations.
Holistic energy renovation could address problems that stem from
unsatisfactory building design standards, construction materials and
methods, or their improper use, operation or maintenance, but
information is needed about the building history, its environment and
usage are needed to act accordingly.
The main goal of progressive BIM methodology is to ensure sufficient
information is available for informed decision making in energy
renovation.

7. Methodology
1. Selection of a case study.
2. Definition of Employer Information Requirements for
energy renovation: existing and missing.
3. Specification of information needs in energy renovation
and evaluation of effort/impact.
4. Building model and boundary conditions for
performance evaluation.
5. Critical information for key decision points for
renovation design options.
6. Development of progressive methodology for energy
renovation of buildings.
7. Evaluation of each aspect.

8. Case study – Office building Brda
• Built in 1945, represents the typology of public office
buildings and is applicable for Directive 2012/27/EU.
• Considered as a Slovenian best practice with ESCO
financing model.
• Renovated in 2015, detailed measured and calculated
data on energy consumption before and after renovation
were obtained.

9. The EIR energy renovation
Technical Management Commercial
Software platforms
Data Exchange Format
Coordinates
Level of geometrical detail
Level of alphanumeric
information
Training
Standards
Roles and Responsibilities
Planning the work and data segregation
Security
Coordination and clash detection
Collaboration process
Health and safety management
System performance
Compliance plan
Delivery strategy and asset information
Data drops and project deliverables
Client strategic purpose
Defined BIM/Project deliverables
BIM-specific competence
assessment
Missing information needs for energy renovation
Historical data
Building’s snapshot
Strategy
Costs
Facility management impact on refurbishment
Asset management
1
Information
category
Effort for
preparation
Impact
Economic Simulation Accuracy
Historical building data
Energy bills All + - +++++ +++++
Repairs All + - +++++ +++++
Previous works (renovation) All + - +++++ +++++
Maintenance All + - +++++ +++++
Building's snapshot
Energy audit All +++++ +++ +++++ ++++
Photogrammetry Geometry +++++ +++++ + +++++
Existing CAD plans Geometry - - +++++ +++++
Manual measurement Geometry + + +++++ +++
Laser scanning Geometry +++++ +++++ +++++ +++++
In situ measurements Materials +++++ +++++ +++++ +++++
Thermography Materials +++ +++ + +
Heat flux measurements Materials +++ +++ + +++
Existing HVAC plans HVAC - - +++++ +++++
Air tightness HVAC +++ + +++++ +++++
Existing lighting inventory list Lighting - - +++++ +++++
Lighting inventory list Lighting + + +++++ +++++
Questionnaire Occupancy +++++ + +++++ +++++
Measurements from national agencies Calibration + - +++++ +++++
Data logger with measurement data Calibration +++ +++ + +
Temperatures and humidity sensory data Calibration +++ +++ + +
Temperature probes Calibration +++ +++ + +++
Thermomanometer Calibration +++ +++ + +++
Probe for measuring CO2 concentration Calibration +++ +++ + +++
Thermography Calibration +++ +++ + +
Energy audit Calibration +++++ +++ +++++ +++++
1
Specification of information needs in energy
renovation (Effort/impact: + low, +++ medium,
+++++ high) – right and Standard high level
structure and contents of EIR - below.

10. Model and boundary conditions
• A BIM model of the office building at Brda was created on the basis
of pre-existing 2D drawings.
• The simulation tool IDA ICE was used for the building energy model
(BEM) and simulation of the holistic energy performance.
• Five different zones were modelled to obtain their impact in view of
the proposed profiles, in building energy efficiency, envelope
properties, set temperature points, occupant density, equipment
and lighting load and building operational hours.

11. Critical information for key decisions
The objective of identifying critical information for decision-
making is to identify key parameters to ensure the suitability of
BIM.
Sensitivity analysis tries to answer the following questions:
1) which parameters have the biggest impact on model
response;
2) which parameters are insignificant and can be eliminated
without notable loss;
3) which inputs contribute the most to output variability;
4) which parameters are highly correlated; and
5) which parameters most affect the FM stage.
The Morris method was used to test 12 uncertain parameters in
the IDA ICE model.

12. Progressive methodology
The progressive BIM approach puts an emphasis on timely data
collection. More information is available, better design in energy
renovation can be made, more advanced and accurate analysis
can be used, and different design options can be evaluated in
more efficient and informed way.
Progressive BIM approach for design goal: optimal energy saving measure.

13. RESULTS

14. Energy performance evaluation
• The dynamic calculation is significantly more accurate
compared to the traditional, stationary calculation.
• Knowing the EP is key factor for Public-Private-
Partnership projects, where the goal is/was to shift all
the risks of not achieving energy savings to the
contractor.
Observation stage
Energy use for heating [kWh]
Measured
Calculated
(monthly method)
Calculated
(dynamic method)
Before 77,318 107,693 71,312
After 15,695 36,86 16,404
Savings 66,623 70,733 54,912
Actual Predicted Proposed

15. Key design parameters
Key parameters that have the highest impact are set
temperature points, thermal capacitance, boiler efficiency,
lighting, and appliances parameters.
Setpoint
temperature
Infiltration rate
Wind reduction factor
Occupant –
activity level
Appliances – emmited
heat per unit
Lighting – luminous efficacy
Lighting – rated input per unit
Lighting – convective fraction
Boiler efficiency
Ventilation – Supply air
Ventilation – Return air
Thermal capacitance
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 2000 4000 6000 8000 10000 12000 14000 16000 18000
σ
µ*
σ/µ* = 1.0
σ/µ* = 0.5
σ/µ* = 0.1
linear
almost
monotonic monotonic
non-linear
and/or non-
monotonic
Influence of design parameters on the total energy use.

16. Sustainability evaluation
• The sensitivity analysis identified key parameters that
require additional research.
• It was found that 9 indicators could be calculated
without acquiring any additional data under the
Functionality category (deriving from BREEAM, DGNB,
LEED and OpenHouse methods).

17. Case study design review
Energy consumption
The reduction of energy consumption and related costs fell from
€ 90,62 to € 40,520, which represents € 49,641 savings.
Time frame
The original plan for implementing the energy renovation case
study was from 30.09.2014 to 31.12.2014, while the actual work
took place between 05.01.2015 and 12.04.2015 – a 3 month
delay.
Additional costs
Additional costs arising from additional, unforeseen works in
design were € 49,800 and comprise of removal of trees and
shrubs, implementation of the electric power-earth connection,
connection and operation on the sewerage network, sanitising
sanitary facilities, energy renovation of the roof, and
rehabilitation of warehouse spaces.

18. Case study design review
• Compared to the initial investment projections, this was an
increase of 18% for unplanned, additional work that could be
avoided with the progressive use of BIM.
• The cost of additional work on the municipal building was
practically the same as the yearly savings achieved on the
three buildings, which means that one year was lost at the
expense of traditional design, although, the Brda case study
was considered an example of best practice.
The improvement of
information collection for
improvement of energy
renovation.

19. References
R. Volk, J. Stengel, and F. Schultmann, ‘Building Information Modeling (BIM) for
existing buildings — Literature review and future needs’, Autom. Constr., vol. 38, pp.
109–127, Mar. 2014.
T. Liebich, K. Stuhlmacher, M. Weise, R. Guruz, P. Katranuschkov, and R. J. Scherer,
‘Information Delivery Manual Work within HESMOS’, p. 19, 2011.
S. Pinheiro et al., ‘MVD based information exchange between BIM and building
energy performance simulation’, Autom. Constr., vol. 90, pp. 91–103, Jun. 2018.
Becerik-Gerber Burcin, Jazizadeh Farrokh, Li Nan, and Calis Gulben, ‘Application
Areas and Data Requirements for BIM-Enabled Facilities Management’, J. Constr.
Eng. Manag., vol. 138, no. 3, pp. 431–442, Mar. 2012.
Kamari, R. Corrao, and P. H. Kirkegaard, ‘Sustainability focused decision-making in
building renovation’, Int. J. Sustain. Built Environ., May 2017.
A. Gökgür, ‘Current and future use of BIM in renovation projects’, Chalmers Univ.
Technol., 2015.

20. References
E. H. Borgstein, R. Lamberts, and J. L. M. Hensen, ‘Evaluating energy performance in
non-domestic buildings: A review’, Energy Build., vol. 128, pp. 734–755, Sep. 2016.
M. D. Morris, ‘Factorial Sampling Plans for Preliminary Computational Experiment’,
Technometrics, vol. 33, no. 2, pp. 161–174, 1991.
M. H. Kristensen and S. Petersen, ‘Choosing the appropriate sensitivity analysis
method for building energy model-based investigations’, Energy Build., vol. 130, pp.
166–176, Oct. 2016.
P. Antoniadou and A. M. Papadopoulos, ‘Occupants’ thermal comfort: State of the
art and the prospects of personalized assessment in office buildings’, Energy Build.,
vol. 153, pp. 136–149, Oct. 2017.
T. Cerovsek, BIM Cube: Information management for digital construction. 2019.
MacLeamy, ‘Collaboration, Integrated Information and the Project Lifecycle in
Building Design, Construction and Operation’. 2004.

21. https://timepac2019.blogspot.com
If you would like to have more information
about this presentation, please contact
gasper.stegnar@ijs.si