1. How do you BIM an existing building?
South West BIM Hub
Ben Rouncefield-Swales
URS – Sustainable Design & Construction 1

2. CONFIDENTIAL PRIVATE INFORMATION
URS - Overview
One of the world’s leading engineering, construction and technical services firms.
Focuses on four key markets:
Infrastructure
Governments
Power
Industrial & Commercial
Fully integrated services support full project lifecycle.
Serves federal, national, state and local government agencies, FORTUNE 500 companies and other multinational corporations.
Approximately 57,000 employees in more than 50 countries worldwide.
Here’s some information about URS – sure you’ve heard of us – one of the larger multidisciplinary engineering consultancies
I think it’s important to say that we also work with a lot of small clients too
Who am I then? 2

3. Who cares about existing buildings?
Buildings are responsible for 40% of global energy demand
So a figure that is regularly wheeled out is that buildings are responsible for 40% of global energy demand – personally I think it’s the humans inside the buildings that are the problem but we’ll put that aside for the time being.
So we know buildings use a lot of energy and that is one of the things that better design and modelling is targeted to tackle. That is one of the aims of BIM – to make better buildings – more energy efficient buildings
Not wanting to teach granny to suck eggs, I’m sure you know these numbers already but I’m going to say them anyway - we have all these targets for CO2 reduction and 70% of the buildings that will be in existence in 2050 are already built.
Yet seemingly 99% of output to do with BIM and building modelling seems to be about new buildings – when as you all know BIM can be an extremely powerful tool yet we’re only really trying to use it on a small percentage of the building stock – the stuff that is actually being built now!
But 70% of all buildings in 2050 are already built

4. What are the Drivers for Change?
Energy costs drive landlords to improve the thermal efficiency of their existing building stock
The EPBD - net-zero energy by 2019 for all new buildings, and carbon neutrality by 2019 for all new commercial buildings
Unable to let E rated buildings from April 2018
Rising energy costs will force occupiers to adopt sustainable operations and improve the efficiency of M&E equipment
Research shows higher rental income secured for buildings with sustainability credentials
The Green Deal intended to stimulate the improvement of energy efficiency in existing buildings
Carbon Liability: schemes like the CRC require private and public energy users to pay a tax on their energy bill
So we know that we need to improve our existing building stock but what are the drivers for encouraging building owners to make improvements;
None of this is new;
More efficient buildings cost less to run – hardly a revelation but interestingly research shows that more sustainable buildings secure a higher rental yield
Coupled with all of this are the legislative drivers which are making it expensive to emit carbon and in the future more difficult to let buildings that are inefficient – From April 2018 you will no longer be able to let out an E rated building – according to some research is 20% of all commercial building stock

5. What is happening now? Traditional energy audits
Cost can vary depending upon level of output required
Some modelling may be done for high investment items – usually at design stage
More involved AM&T contracting
High cost and long contract periods
Creates good data but still need to work up into opportunities
Typically outputs are data not models
Energy Performance Contracting
Investment grade energy audit
Detailed modelling to underpin finance
No initial cost to client but pays through savings
Do It Yourself
Success varies depending upon in-house skills
Unlikely that any modelling would be done
So how do we currently assess and work with existing buildings to improve their efficiency?
I’m not saying this list is exhaustive but I think it captures the main approaches
First thing that I notice about all of these perhaps the exception of the traditional energy audit take a long time to develop with mixed results and can also be expensive. – and then even the traditional audit can take a long time to develop robust opportunities and savings beyond just recommendations.
In addition I think it is fair to say that generally there is a poor understanding of the performance of existing buildings and the interrelationships of the different elements that influence the efficiency of a building.

6. Wouldn’t it be nice….
If we could determine energy savings for existing buildings using a method that is…
Comprehensive
Quick
Accurate
Inexpensive
Able to leave a legacy that is useful in the future
Wouldn’t it be nice if we had a tool to determine energy savings for existing buildings that was as effective as some of the best established methods but was quick and cheap to deploy yet accurate and provided a useful legacy that could be referred to an altered in the future.
Ideally something which takes the best bits from each of the services described on the previous slide.
I also think the key in this day and age is the 4th bullet in that list – inexpensive because at the end of the day – as shown on the previous slide there are all manner of methods established to work with existing buildings but each has their limitations and combining a number of techniques becomes expensive.

7. That’s why URS developed REM
Rapid Energy Modelling
A tool developed by URS in partnership with AutoDesk
Uses innovative means to quickly construct a 3D model of the building
Physical Audit feeds information into the model
ReVit models the building and tests improvement measures
Ouptut leaves a legacy model for the building
MANAGE
BUILD
DESIGN
PLAN
Precisely why URS developed REM
It’s been a work in progress for a couple of years really, developed in partnership with AutoDesk – features required to undertake REM are now included within revit.
Part of what makes REM so innovative is the means by which it constructs a 3D model of the building which I’ll show you in a minute.
Also critical to REM is the physical audit – basically a traditional energy audit which feeds information into the model such as HVAC, lighting, building fabric etc
Revit then combines the 3D model and the information from the audit to build an energy model of the building which can be used to test improvement measures and can evolve with the building so that it stays as a useful resource

8. Improvement simulation
The REM process
Information capture
Physical audit of building
3D geometry capture (multiple approaches)
Computer model
3D geometry defined
Building characteristics identified: fabric, services and systems
Location, climate and occupancy profiles
Building performance
Modelling engine produces simulation
Energy required for heating, cooling, lighting, hot water etc.
Improvement simulation
Model is modified to represent improvements
Results illustrate benefits in energy reduction and emissions
A bit more of a detailed look at the – 4 key steps
Data capture: photogrammetry, satellite imaging, laser scanning, 3D sketching, energy audit data - Why Smart? Three dimensional geometry model which is embedded with properties relating to building fabric performance, occupancy zones and energy plant, together with orientation and aspect, local weather trends etc.
A Rapid Energy Modelling engine calculates the baseline energy and CO2 emissions – Cloud computing power delivers the results in seconds
Users identify priority areas where the biggest improvements could be made – for this particular building, heat gains, causing cooling are one of the largest demands
Simulate the impact of improvement scenarios on energy demand and CO2 emissions, but also on the internal spaces, looking at quality of daylight and environment for the occupants
We use this data to model life cycle cost of the improvement scenarios to demonstrate savings and payback, enabling investment decisions to be made.

9. Data Capture
Some examples of the sort of information that is captured – as I said – a traditional energy audit really
Once you’ve gathered this information you need to build your 3D model of the building – there are many ways to do this

10. Laser scanning
Laser scanning creates a very detailed model of the building automatically, but is relatively time-consuming and unobscured views are required.
This is our Basingstoke Office

11. Photogrammetry
Anybody with a camera and ten minutes of tuition can take the pictures to feed this software which derives 3D wire-frame model
URS have successfully used this technique for a number of REM projects

12. Photogrammetry
Even if site access is unavailable, we’ve successfully made a model from satellite imaging tools

13. 3D sketching
OR – if you have a 2D plan of the building a quick method is to use Autodesk’s 3D model authoring tool to extrude the building from the two-dimensional ground floor plan.
We specify percentage glazing and orientation, and the model is ready
Message – we can model any building through one of the approaches

14. Rapid Response From a floor plan – in 30 minutes
Generated from 2D plans & elevations using AutoCAD, Revit, Vasari, Google Sketchup etc.
From the laser scan – in 2 hours
No drawings required – photogrammetry builds a 3D model
This is one of URS’ offices
Innovative data capture really speeds up the process - the quickest method in this instance was to use Autodesk’s 3D model authoring tool to extrude a 5 story building from the two-dimensional ground floor plan. We specified percentage glazing and orientation, and the model was ready
Message – we can model any building through one of the approaches

15. Immediate decision making
Provisional model and scoping some options to workshop after 1 day of site survey, data capture and initial modelling.
Unlike a new building we know what the energy use is because we have many years of billing – this means we can test the model! For every REM project we build the model, run it and then compare against actual billing to see how good the model is
Output helps users to identify priority areas where the biggest improvements could be made – for this particular building, heat gains (via the windows), causing cooling systems to kick in, are one of the largest energy demands
Depending on scope of work this almost immediate diagnostic support translates into lower capital outlay to determine initial prognosis - where to spend for maximum energy impact

16. Option & Sensitivity Studies - Readily Undertaken
Unimproved
With external shading
Alter key building elements and observe impact on energy & CO2 outputs and also quality of internal space
Occupancy comfort – good example of impacts of investment decisions on the overall building environment.
Here we are simulating daylight levels inside the URS Basingstoke hub - red in these images shows high daylight levels, tending towards glare at the most extreme.
The left hand image is the standard building and the right hand shows a type of shading which we modelled. You can see it cuts down the high intensity day lighting in the bottom left hand corner, but day lighting levels across the floor are largely unchanged.
The tools can be used to look at internal temperatures, thermal comfort, views out and all kinds of quick, useful quantified visualisations to clearly demonstrate how the changes will work

17. Example output - recommendations
Short Term
Medium Term
Strategic 1
Space set points on heating system 17
Solar Thermal 20
Upgrade lighting to LED 3
Time clock on water heaters 16
Thermal performance – Ext. Walls 22
Draft lobby at main entrance 5
Replace boilers 14
Energy heat meters 24
Thermal performance-windows 4
Upgrade time clock system 19
Photo Voltaics 15
Slave Terminals 7
Daylight dimming system 18
Thermostat & time control 6
Install PIR control 23
Occupancy sensing on cooling 2
Variable Speed Drives 21
Thermal performance - Roof 8
Repair Damaged windows 12
Lighting zoning and control system 13
TRVs 9
Reduce door air leakage 10
Adapt T8 to T5 light fittings
Then once you’ve modelled all of the relevant improvements and prioritised them in terms of payback and impact to can choose whichever output best serves the end use for the data;
you can put them in a MACC curve to form part of an energy management plan, use the outputs for CAPEX justification, or use the data for any other process which requires

18. Case Study 18

19. City of London office - introduction
Late-Victorian office
Multi-tenanted
Circa 3,500 m2
7 stories
Energy spend c. £50k p.a.

20. City of London office – REM
Site visit circa 3 hours
Photogrammetry model
Rapid Energy Model created
Accuracy <10% difference
We spent about half a day on site gathering all of the data
The model was built using photogrammetry
Once the model was created we were able to check the output against the actual billing data which revealed that it was within 10% of the real data. At this point you can try to tweak the model to bring it closer to the real data if necessary but actually we regard within 10% as good enough – accepted by our EPP organisations *
*includes small power, computers, communications equipment, printers etc

21. City of London office – Improvement Recommendations
Low Cost, Quick Wins
Medium Cost
Strategic
Energy cost saving (p.a.)
£ 10,260
£ 9,570
£7,550
Carbon emissions saving (p.a.)
21%
19%
15%
Specific improvement measures
Review and implement Good Practice recommendations (behaviour & operation)
Install Voltage Optimisation Unit
Upgrade lighting to LED lamps in appropriate areas
Install time clock on water heaters
Install lighting PIR occupancy control
Install occupancy sensing on cooling systems within meeting rooms
Interconnect existing control systems
Install daylight dimming system
Install thermostat and time control on electric panel heaters within communal parts
Adapt T8s to T5s in main office
Replace laptops / docking stations / terminals with "mainframe" and slave monitor and keyboard terminals
Implement energy metering strategy
Replace centralised hot water with point of use hot water supplies
So once we’re happy with the model we can test the benefits of all of the identified improvement measures and then rank them in terms of cost, impact and ease of deployment.
It should be noted that at the moment these savings are for individual measures as the model isn’t yet able to distinguish between those that are mutually exclusive and those that aren’t

22. City of London office – Improvement Recommendations
Here’s a graph

23. REM experience across the Built Environment
REM studies undertaken since March 2011
Accuracy consistently <±10%
Average CO2 and energy savings identified circa 40%
Oxford University
Student Accom.
URS Basingstoke
Office
AB InBev Belgium
Manchester Council
Office (Nat vent)
URS Nottingham
Office and Labs
AB InBev Bremen
Major Property Man.
Office (Period)
Gateshead
Housing Block
Above all, this can be done quickly

24. Summary 24

25. Key issues Lots of buildings – most already built
Poor understanding of building performance
Traditional audit / survey take a long time
Need to act now to meet commercial imperatives:
Delivering cost savings
Improving energy performance
Enhancing working environment
Reducing carbon emissions

26. What benefits will REM bring?
It helps reduce a building’s energy running costs and CO2 emissions
It provides a rapid focus on building improvement options
It is a Building Information Modelling (BIM) process, creating a legacy model that can be retained and refined
Improves building user environment
Above all, this can be done quickly

27. What about the nitty gritty?
Cost for one-off single building REM study – circa £5k
Scalable for with economies building portfolio
Turnaround time – 3 weeks (from site visit and info received)
Process loads and unusual buildings add complexity!
Step 1 in “Energy Management” offer
The future – UAV surveys

28. Thank You Ben Rouncefield-Swales Associate
URS – Sustainable Design & Construction 28