Building Information Modeling (BM, BIM, and NBIMS)

Building Information Modeling (BIM) has been described by the American Institute of Architects (AIA) as "the most significant transformational event in our business for the past 500 years". Today, it also means different things to different people. The National BIM Standards (NBIMS) is an effort to change the entire facility design, construction, and acquisition process to catch up to best practices in other engineering and financial disciplines.

There is an unfortunate confusion in terminology I must address early on. Building Modeling refers to mathematical models of a building, including its materials, so it can be analyzed prior to construction. Using a building model, blueprints and construction documents are mere projections or reports of the underlying model. The Building Information Model comprises all of the information involved in the design, construction, and operation of a building, beginning with the earliest design intents. The Building Model is just one portion of the BIM, and the NBIMS specifies that the building model follow certain standards.

A recent article published by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), suggested that using BIM offered the following benefits:

Design:

• 20% to 50% reduction in Design Cycle Time
• 100% Accurate Procurement package

Construction:

• Time and Cost reductions 20% to 40%
• Reduced Rework

Operation:

• Life-Cycle O&M reduction 10%-40%
• Reduced Handover/Turnover time

Even these numbers represent only a part of the benefits. Last year, the International Codes Council (ICC) demonstrated automated code compliance checking of a BIM; their goal is same-day code compliance review. The latest Energy Modeling software is able to reads the BIM directly, enabling iterative modeling as the design changes. Many of the current engineering, environmental, and design initiatives start with the use of BIM as a requisite for participants. BIM is seen a key enabler for future energy systems, from the Galvin Electricity Initiative to the GridWise Architectural initiatives, to the Zero Energy Commercial Building.

The goal of NBIMS is a common framework and format for sharing BIMs across vendors and organizations. Most CAD vendors, including AutoDesk, Bentley, and ArchiCAD read and write BIM datasets. Increasingly these BIM datasets are NBIMS compliant. Using NBIMS, data developed during initial programming is transmitted with design and operation data, and all information continues to add value throughout the facility life-cycle.

BIM is so large, and so important, that it is hard to understand. Instead, like the blind men and the elephant, we can stumble toward it from a variety of perspectives. In the near future, I plan to set some of these blind men loose, and see what they grab…

Abstract the Interfaces

If we are going to build very large systems, we will need to break it into self managing units, and build systems of systems. There is too much complexity and variability to establish any type of top-down order on embedded systems. Even if we could define the “optimum system”, we could still not use it for something as large as the power grid.

Suppose we did. Suppose we picked a technology and said “This is what each building shall have!” In 20 years we would still be trying to get all systems upgraded – and we would be mandating 20 year old technology. We simply cannot make rigid decisions for anything so large, so extended, and maintained by so many people.

We can only manage such a large scale by hiding complexity. We must hide complexity by defining certain simple big picture interactions that encompass all the little decisions. We will never get support for central coordination if by doing so, we remove personal control from systems. To define these simple actions, we need to reach for commonly agreed upon semantics to describe the operations we want systems to follow.

I want to place Intelligent Buildings as fully actualized agents on an Intelligent Grid. To do that, I hope to leverage the Building Information Model (NBIMS) to discover abstract interfaces to the point-by-point complexity of the underlying control systems. Rather than create these abstract interfaces from scratch, I hope that the pre-existing interfaces between the Building Model and Energy Models could be a good starting point. I want to avoid the complexity of introducing Yet Another Acronym and Yet Another Interface, and thereby avoid increasing complexity.

Abstract interfaces that hide rather than reveal complexity are the key. Here is an example from within oBIX discussions. When we discussed abstract interfaces for scheduling, each control system developer quickly claimed that “scheduling systems algorithms are quite complex, and there nearly impossible to align.” Spirited discussions ensued about factoring how long it takes to air condition a room in advance. Should we factor in humidity. and on. and on.

But there is already a standard for scheduling. We each receive ICAL invitations to meetings scheduled on the internet. ICAL is a W3 specification, meaning it is defined by the same folks who define how we display web pages. Our personal systems know how to adjust for where we are in the world, including such local oddities as when Daylight Savings Time begins. Each of us considers whether we have to drive to the meeting, or fly, or simply be near a phone. Those details are not the concern of the interface but of each participant and of the complex systems we represent. I want to simply invite the conference room or class room to an event on a certain date, with a certain number of attendees anticipated.

If these questions are answered correctly, they expand the value of capital assets by extending their ability to provide services and amenities to the owners and tenants, not merely to avoid costs. An Energy Model consists of Envelope, Weather, and System Operations. An abstract interface that works for energy modeling could be re-usable in tuning System Operations in response to Weather Predictions to improve quality of service provided. It becomes the basis for external system analytics to enable predictive maintenance and thereby economically provide enhanced reliability.

Abstract interfaces are the first step to defining services. Services are the key to continental-scale integration. Services allow for internal intelligence to support local imperatives. We can call that local intelligence an Agent. Agents are the key to large scale interaction, because they can assume responsibility for local operating details. Semantics are important, because we must have some common vocabulary to communicate with the local agents.

It almost goes without saying that any agent would be offended if you tried to communicate past its semantic surface. Even your kids will get in trouble if, instead of asking for money on a Saturday night, or perhaps even volunteering for chores, they reach directly right into your wallet. The surfaces of services must be inviolate.

And that is how we will handle the complexity of integrating a continental-scale power grid with its end nodes.

Thinking about what I want

Yesterday, the FIATECH focus group met to review the Capital Projects Technology Roadmap. I sat in as representative for the roadmap’s Element 5. Element 5 is titled The Intelligent Self Maintaining Self Repairing Facility. In case you were wondering, last night’s post was a summary of Element 9 from the roadmap. On the way, I stopped in the Frederick, Maryland, IHOP, fueling up and planning what I would say if they asked me what I, or the 5^th Element, required as top priorities.

BIM for Control Systems

No one is using BIM to define control systems. Just as chip design was the last part of electronics fabrication to be computerized, the most technical part of construction is the last to be designed. As the Director of Buildings at UNC once said, “Control systems are designed by a man standing on a bucket.”

BIM for control systems will codify standards for design and develop formal semantics for the services provided by each control system. These system semantics will be linked to the formal performance metrics to measure explicit performance goals. Retro-commissioners know that the problem restoring systems to their original design is that, in many cases, the design does not work. If these systems were fully designed, they would.

Life Cycle Commissioning

Design intents should indicate goals for building performance. When a building model is developed, the energy model should be run directly out of the building model. The energy model should then be compared to the design intents. The energy model, then, becomes a means of commissioning the design against the design intents. The process should be repeated as the design is changed, particularly after value engineering. These energy models then become the basis for traditional commissioning.

The performance goals and metrics developed early in the process are then available to the traditional commissioning agent. The commissioning information should be entered into the building information store to be readily available to service personnel or retro-commissioners.

Since many of the measurements are based upon designed control system metrics, there is no reason not to take those measurements every day – and analyze them as well. Instead of waiting for system components to fail, this would allow regular review of how each system is performing as a system.

Service Oriented Building Systems

One we have the building semantics and building metrics defined during design, then we have the core pieces we need expose control system interfaces as services. No one other than maintenance personnel ever has a reason to issue instructions to a building system except through a service interface. Services hide complex processes and expose only those interactions that are appropriate for the tenant, the landlord, or the enterprise system.

Security definitions of standard roles.

We need standard role definitions to control access to the service oriented building systems. Based upon design intents, the designer can assign particular functions to roles known to the building system. A first pass might be, in order decreasing privilege, Operator, Landlord, Tenant, Visitor, Guest. Maintenance would not be restricted to working through the service interface, and so needs no special role.

Along with roles, we need standards for defining building zones. Zones might be rooms or groups of rooms. They might be determined by cooling system or by security needs.

The job of the building systems integrator then becomes matching control functions and sensor points to zones and assigning internal operations to roles. With identity determined by a third party, the intersection of zones and roles as assigned to each identity provides the basis for secure interoperable building operations.

So that’s my wish list. Too bad I had to leave after one day to go to Grid-Interop…they never got to ask.

Lifecycle Data Management and Information Integration

(This post was prepared during a FIATECH workshop on capital project priorities)

Do you find capital projects seem to ask the same questions again and again. Promises made in programming are lost in delivery. Contractors are unable to guess what the designers wanted. It can be hard to discover if you got what you asked for, and if everything works as promised. Do you wonder if your staff will be able to maintain a new facility in the right way, with the right parts, so you are unsure you will get full value from your investment?

Background:

A 2005 NIST study of the costs of poor interoperability estimated that $16 billion was lost each year in the capital industry.

Vision:

All information associated with the design, construction, and operation of a building is captured and maintained for the life of the asset. Standard interfaces let any authorized person access the information they need using the tool they want. All design information and choices are available to the contractor during construction. During building handover, the commissioning agent compares results to the goals and promises made during design. Maintenance personnel have direct access to all information they need for best results.

Challenges:

The most significant challenges are cultural and organizational rather than technical. Contracts must demand delivery and sharing of all information in existing standard formats. Business processes need to be recast to reflect new responsibilities and liabilities; contract language must be adjusted.

Benefits:

Eliminating the costs of re-creating data and improving operations through appropriate access to information will reduce costs of acquisition and preserve asset value. Common data formats will improve interoperability at every stage of the facility life-cycle, increasing accuracy. Interoperability will increase competition and drive innovation while increasing accountability.

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