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How do you BIM an existing building?

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Presentation on theme: "How do you BIM an existing building?"— Presentation transcript:

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

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

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