Digital Twin Q and A - Part 1

Last month, we partnered with the B1M to host an online panel discussion “Here’s the Key to Net-Zero Buildings” as part of our COP26 programme of events. During the panel session, experts from across the built environment discussed the use of digital twins and their potential to create net-zero buildings. Our digital twin project with Glasgow University was used as the starting point for the debate, which then lead into a broader discussion around the power of digital twins.

During the session we had some fantastic questions coming in from the audience. Given the volume of questions, we didn’t have time to answer them all on the day so we’ve collated them here for you to read in a set of blog posts. Part 1 covers the questions we received about the Glasgow University project and questions around what is required to create a digital twin.

We hope the answers below help provide more insight on digital twins and their application in the built environment. You can find the answers to all the questions from the webinar in the full Q&A document.

Q: Will the recording be available after the webinar?
A: A recording of the Here’s the Key to Net-Zero Buildings webinar is available to view here.

University of Glasgow Project

Q: Can the public access the Glasgow University dashboard?
A: Yes, there will be a publicly available dashboard in early 2022. This will be anonymised for the campus but will allow visitors to see what the University are doing on their smart campus.

Q: Is this a case study on IES website?
A: Yes, you can ready the University of Glasgow case study here.

Q: With regards to Glasgow University, how did you manage to accumulate the building fabric data, knowing the inaccuracy and lack of data held in O&M manuals. Knowing metering data is important but this must be supported by accurate building envelopes/fabric data for existing buildings of varying ages?
A: First, we would do an energy audit of any building to identify how the building is being used, what unregulated loads there are and an assessment of the fabric and age of the building. If no data is available for the fabric, the option is to carry out a detailed assessment drilling small bore holes to identify what the make-up of the fabric is, or alternatively assessing the age of the building and what the likely make up would be based on the regulations at the time. The other option is to carry out a dynamic U-Value test on the building to achieve a high accuracy of the U-Value of the envelope. All methods can be used depending on the level of accuracy you wish to achieve.

However, we also now have an optimised calibration tool, where all ‘known’ parameters can be set and then any ‘unknown’ parameters are optimised against the given standard you are calibrating too, e.g. IPMVP or ASHRAE 14.0. This will then set a value for the unknown parameter, which could be the U-value of the envelope and then an assessment would be made by the engineer as to whether this is reasonable for the type and age of the building.

As with anything, it is not an exact science, the goal is to have a Digital Twin that as closely represents the building as it can be, given the limitations you might have with respect to data of the building.

Q: Does the university allow any of its students access to the hard data from the Digital Twin? The students could then see, where they could make changes to the buildings on campus to reduce the emissions from those buildings and also gain educational knowledge in the process?
A: The academics on the campus are using the IES technology with their undergraduate and postgraduate courses with many students creating Digital Twins of the buildings themselves. As such, the answer is yes that the students are engaging with the software and gaining education on how to reduce campus emissions as a result.

Q: What do you think are the barriers to adopting this kind of Digital Twin at other Universities? Do you think it is related to cost or lack of knowledge about the benefits?
A: Like all advancements in technology, adoption requires upskilling. For universities, not only do academics need to learn the tools, they need to be competent enough to teach it to their students. The living laboratory approach also relies on collaboration between the estates departments and academics – two parties who traditionally seldom interact.

There are also barriers with respect to accessing the data from BMS or other systems and upskilling in particular the IT departments to help to do this. There is also education needed in the early design stage of projects to ensure the correct type of equipment is specified to enable the creation of a performance Digital Twin, including sensing technology and items such as servers to enable access of building related data.

Whilst the creation of a Digital Twin requires some initial expenditure, savings tend to pay for the Digital Twin within the first year, depending on the age and condition of the built asset.

Q: In the University Project what % of the campus would you say is currently being monitored as a Digital Twin?
A: Currently approximately 10%.

What’s required to create a Digital Twin? (i.e. DT tools, training, building info/data, what goes into the model)

Q: What sort of data goes into these models? Meter readings? Live sensor data e.g. temperature/humidity?
A: Any time-series data from BMS/BEMS, automatic meter readings (AMR), sub-meters and IoT sensors can be brought into our cloud-based data analytics platform, as well as historic data (CSV, JSON, SQL, XML).

Data from utilities, sub-metering of electricity, natural gas and heat, temperature, humidity etc. can all be used, ideally hourly recordings over a 12-month period as a minimum to account for season fluctuations.

Q: How difficult / easy is it to train people to use Digital Twins? Does it take much educating?
A: IES offers basic and advanced levels of training to support users in learning to use our Digital Twin technologies, however, users are expected to have a good understanding of energy performance in the built environment and any previous experience in energy modelling, particularly with the IES Virtual Environment, will accelerate the learning process. Find out more about our training options here.

Q: Do we need an existing building with lots of previous data to be inputted, in order to build a reliable Digital Twin for the building or maybe new buildings can also have their Digital Twins which would perform at least closely similar to the real buildings?
A: Digital Twins can be used for both existing and new buildings. The Digital Twin can also be used to support the construction and commissioning process to help close the performance gap.

Q: How does a Digital Twin software provider, e.g. IES, interact with controls vendor or BMS to gain access to data to calibrate building simulation models?
A: The data required to calibrate the Digital Twin must be brought into iSCAN, our cloud-based data analytics platform. The BMS within a building can be setup to automatically send data to iSCAN, or data can be imported manually. For additional information, please refer to the following guide.

Q: What’s the biggest hurdle to take building simulation model, “energy model”, to level of “performance” Digital Twin?
A: A performance model must reflect the actual building far more than typical energy models (i.e. compliance models, CIBSE TM54 etc.). The biggest challenge may be gathering all the as-installed building information/data, therefore sufficient time should be allowed for within the programme for creating the initial Digital Twin.

Q: Does the Digital Twin take into account non-regulated electrical energy in the building?
A: The accuracy of the Digital Twin is dependent on the accuracy and completeness of input data. Therefore, the Digital Twin should always include any non-regulated loads.

Q: With Reference to Digital Twins. As consultants how can we deploy IES software and Tools to help inform and advise clients?
A: As with our Virtual Environment software, licenses and training can be provided to enable consultants to deliver their own Digital Twins to their clients. IES’ in-house consultancy team can also support consultants with the delivery of Digital Twins, with decreasing levels of involvement.

Q: Hello! Is it possible to create digital energy twin in the IES Virtual Environment? And if it is possible, what might be the main steps to do it?
A: To create a Digital Twin of a building, the IES Virtual Environment is required, along with iSCAN, our cloud-based data analytics platform and our new Calibration Tool which will be launched in early 2022. There is a specific workflow that should be followed to create a performance Digital Twin. IES can provide training and support on this.

Q: As a structural engineer, where do we really start? Is it a case of sharing the design information of projects to a specific body? Is this something that would be enforced in the future?
A: Design or as-built information will need to be provided to the party who is creating the Digital Twin, this typically includes architectural and MEP information as well as operational information and building data.

The goal is to unite all across the building  ifecycle from early concept design to end of life to share data and enable performance Digital Twins, this will require interoperability between tools. It is coming but there is a long way to go and digitalisation of the construction sector needs to become more than just improving build time and reducing build cost or looking at sustainable materials and instead linking to the final end use of the building and ensuring the building performs as expected.

Q: Are the Digital Twins in IES able to be linked to Autodesk Revit models (or equivalent models)? My co-workers aren’t receptive to the idea unless I can show them it’s easier since there’s rarely a budget to learn this new process.
A: Revit models can be imported into the IES Virtual Environment to reduce duplication of modelling the building geometry. For more information, please visit our FAQ.

Q: I am a Ph.D. student in the power engineering field, and I have a task to make a Digital Twin. For now, it seems overwhelming, because all information I can find is very basic. What are the first steps for building a Digital Twin?
A: The first steps for creating a Digital Twin is to establish what purpose will it serve? If you are planning on creating a Digital Twin of a single building, you will require architectural floor plans, elevations and section drawings along with any documentation on the installed building services. Many buildings have Operation and Maintenance (O&M) Manuals which may include some of this documentation, however, a building survey may also be required.

You will also need to consider what data is available (what is being metered in the building and how frequently the data is being logged). Finally, you will require access to our Digital Twin technologies and
associated training.

Q: When simulated models don’t match metered readings, how do you decide what the difference is? missing equipment not modelled vs the actual building running inefficiently vs a Perfect simulation for example? Do you purposely make your model controls worse?
A: Simulated data can be compared against real data within iSCAN. Any significant deviations can be investigated and adjusted within the model. The model is also calibrated to international standards such as ASHRAE 14.0 and IPMVP.

Q: Does the Digital Twin work floor by floor, or is it customisable down to the room level? I’m wondering if specific assets are taken into account throughout a building, such as radiators, windows, room volumes, HVAC systems in each room, wall insulation, or if it’s more generic?
A: A Digital Twin of a single building can be modelled at room level, factoring all thermal and energy transactions within the room, surrounding spaces and the external environment (i.e. heat losses, internal and solar heat gains, HVAC, building fabric, air exchanges etc.)

Q: How much does Digital Twinning software cost?
A: Please email for a detailed quote for your building(s).