Many of the best builders use ephemeral models today. Contractors generate their own building models. They create these models are created prior to the bid, to address the inadequacies planning using he traditional building system drawings. When he wins the project, the contractor will use this model throughout the construction process. This model is then discarded, as it is not specified as part of the project deliverables, and could create additional liability. It would be far better, and far more efficient, is these models were based upon the designer’s models, and were included as project deliverables at building turn-over.
Without a design process that actually includes the mechanical systems and their controls, there is no underlying operational model for the building. Without an underlying model, ongoing system maintenance is based upon guesses. Without live performance metrics, including instant access to energy metering, linked to that model, than building system operations are based upon experience and guesswork. When the system is green and non-traditional, you can eliminate experience, leaving only guesswork to operate the building, and to tell if the building is being tuned into or falling out of control.
The solution to these problems is an integrated data model for the building whose life extends as long as the life of the building. The data model starts with the capture of the design intents. Building designs should be models, not drawings, and should be standards-based. The energy model, for example, should run directly off the building model and could be compared to the design goals. Changes to the design, especially during value engineering when many innovative features are eliminated, could be automatically reflected in updated energy models.
This building model should be available electronically to each bidder and used throughout the construction process. The increased accuracy of the bid package and reduction in change orders during construction would reduce costs and result in as-built models that match the initial design. These accurate designs, would include full identification of the internal systems, their components, and their performance expectations.
With delivery of the as-built models, using system identifications consistent with the initial design documents, then building commissioning becomes validation of performance to the design. In the case of energy systems, commissioning becomes validation to and alignment with the energy model. This, at last, becomes a significant improvement over the traditional standard, described only half in humour, as “no sparks”.
This persistent design model would become the basis of maintenance and operations decisions. Maintenance staff would have ready access to design and commissioning documents keyed with the same systems identifications. Field notes and best practices discovered for one system could be made automatically available to all similar systems using the information model. acts necessary to support innovative systems would be available to maintenance and operations throughout the life of the building.