The changes in construction created by building information modelling

While building information modelling will further sustainable construction, it will also usher in a complete change in the design and construction of buildings. By Richard Ward, head of construction, Eversheds.

Building information modelling (BIM) is more than just a new type of software. It requires a different approach to design and construction processes and will substantially change the sequence of activities and responsibilities of the parties involved at each stage. What follows is a summary of the issues and risks that will need to be addressed by users of this technology if they are to avoid the potential pitfalls of embracing this paradigm shift in the approach to the design and construction of buildings.

What is BIM?

BIM is a model-based technology that uses one database for all elements and processes relating to the design, construction and use of a building. It is a digital representation of physical and functional characteristics of a facility. As such, it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life cycle from inception onward.

National Building Information Modelling Standard

In simplistic terms, it is an intelligent model containing objects which themselves have attributes and a database. Unlike traditional 2D design, the model holds all the information about the various elements and how each element relates to another. Therefore, for example, a beam will not merely be described by a set of adjoining lines, but will have all the parameters required to represent a physical object such as materials, its method of connection to adjacent elements and perhaps even cost.

Design information from all disciplines is fed into the BIM database - from architectural designs and specifications to structural and M&E systems. The database contains and connects all elements of a completed building to one main database of linked project information. Thus, for example, if a change were made to one element of the design, the sophisticated BIM database would automatically reconfigure all related elements embedded in the interrelated database. A BIM database will go well beyond the traditional use of 2-D modelling and will have the capacity to work in 3-D, 4-D (construction scheduling) and even 5-D (costflow analysis).

The database could dramatically reduce waste in construction, including time delays caused by requests for information and design changes. It would also detect design errors and omissions in the early stages of a project and would facilitate just-in-time delivery of prefabricated components and plant rooms, thereby saving time and costs and reducing health and safety risks.

Pitfalls and liabilities

Existing contract forms do not accurately contemplate the inter relationships of parties using BIM. The clearly defined boundaries between the different stages of design and construction and between the different disciplines are lost in BIM. If all designers are working on the one model and are capable of changing the model, then who is responsible if there is an error? Areas that need clarification include:

• Who owns the model?
• Who owns the copyright to the elements of the model?
• Who is responsible for managing the model?

These all need to be addressed up front if disputes are not to arise further into the project.

Copyright issues are a significant concern for all parties. BIM requires designers to collaborate and work together on the model. Therefore there is a difficulty in identifying the work of individual participants. Substantial investment is required by engineering firms rolling out BIM technology. Of great concern to these firms will be ownership issues in relation to libraries and sub models developed on an investment basis. It is important to ensure these are protected.

Similarly, if all disciplines have contributed to a model and there results an error which causes delays, cost overrun or performance issues in the final building, it may be difficult to establish who is at fault. Each discipline will continue to be responsible for its own area of work and input. However if that discipline has relied on part of the model created by another designer and the original element contained a mistake, then it is likely that the original designer is responsible, at least in part.

It is important that roles and responsibilities are clearly defined at an early stage, so that designers know the level of risk that they are being asked to accept. The legal documentation will need to be drafted to ensure that liabilities are allocated and known in advance.

This is a system in an embryonic stage of development; and the parties must be alive to the need for innovative drafting of the relevant legal documentation. In addition, it is likely that new insurance models will be created to deal with the partnering arrangements required for the successful utilisation of BIM.

Standard system

It is likely that BIM will be used on many major projects in the immediate future and may indeed become the standard system used in the design and construction of building in the longer term. It may well reduce build periods, create more certainty around the predicted performance of buildings and more opportunities to engage in sustainable design. It is a tool that would significantly assist the industry in achieving the business critical objectives identified in the recent review of the Egan agenda Never Waste a Good Crisis, which focused around value over the life-cycle of built assets.

Additional reporting from Gráinne McCormack and Mary Anne Roff