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01 / Introduction

There is very little, if any, useful published data on the true cost of building information modelling (BIM) on a construction project, covering all the relevant costs of using BIM and comparing them to the monetised benefits.

As long as a project is set up in a manner that allows the benefits of BIM to be realised, the cost of the investment should be at least met 鈥� and probably exceeded.

Project teams are certainly becoming more adept at using BIM, with efficient working practices that should negate upfront costs and therefore not make a material difference to overall fees (other than the fee profile).

The creation of a clear, developed, coordinated design that reduces latent risks represents an over-riding commercial benefit.

The likelihood of these gains being realised will no doubt increase in the future, as teams continue to navigate their way through the teething pains of a new technology and a new way of working.

The latest NBS National BIM Survey revealed there was still much work to be done to increase adoption of BIM: less than 50% of UK respondents use BIM, and nearly 70% said the industry is not even clear enough on what BIM is.

Here, we compare the likely relative levels of costs and benefits of using BIM, based on the knowledge Alinea has gained over the past few years, and through talking to a selection of design team members.

02 / Costs vs benefits

There are a number of direct costs associated with BIM, which can affect all members of the design and project teams.

These include:

• Investment in upgraded hardware (`which can be mitigated by the use of cloud services and 鈥渟lave鈥� computers)
• Software licensing, with individual software subscriptions costing upwards of 拢4,000 each per year
• The salary premium of employing personnel trained in BIM software
• The training of existing personnel
• The scale of record keeping required 鈥� memory, storage facilities and processes that have to cover all models.

Many of these costs are incurred at the start of the project, but this is also the point at which many of the benefits can be realised.

It is important that the entire technical BIM team 鈥� members from each discipline, including the cost consultant 鈥� invest time in planning, shaping and reviewing the modelling methodology.

BIM requires a lot of data, and it needs a robust framework to make it useable and avoid abortive work.

Therefore, a model development plan should be created: this is an agreed roadmap for how usable data should be structured in the model, including project specific requirements, the software chosen for drafting and harvesting data, and the file format exchange.

Clear, early planning from the whole team can help to realise the following benefits of BIM:

• Quality is controlled and assured. Much more is recorded 鈥� including earlier client decisions on design
• Components, detailing, coordination and the 鈥渂asics鈥� of design are handled more efficiently
• The process itself is designed, mapping what is needed and when, and prompting thought about content
• Greater information is included earlier (such as the performance criteria of components) and can be more easily amended
• Greater client involvement should enable faster, better decisions
• The technology brings people together: the process encourages each discipline to consider the needs of others and who else should be contributing
• Complex situations can be presented with clarity, enabling a better understanding.
• 鈥淏efore and after鈥� analyses can be undertaken easily.

For clients

Earlier design development and coordination means there are more upfront costs for the client in terms of fees. This, in turn, means there will be higher abortive costs if the project needs to be redesigned or abandoned. The client also needs to invest more of its own time in the early stages 鈥� to determine the brief, set up the project for BIM and make design decisions.

For these reasons, the client has to be convinced that the earlier inputs will drive cost, procurement and programme benefits.

Here, the fact that BIM is a powerful communication tool, with enhanced visualisation, becomes an important factor.

They may also need to employ a separate 鈥淏IM manager鈥�. This is a contentious issue, as it is sometimes argued that this should not be a separately defined role, but simply the designer鈥檚 coordination responsibility under the BIM process.

For designers and engineers

Designers will face initial legal and professional costs when they adopt BIM, not only to ensure that appointments are satisfactorily worded, but also in terms of insurance provisions. There is also the perceived 鈥減rofessional cost鈥� that comes with the fear of designers becoming subservient to the software.

However, speed of output and coordination results in a greatly reduced number of hours being spent on drawings. One architect suggested it could produce a detailed planning application for a 100-unit residential development in just three weeks.

For cost consultants

The benefits to the project of the cost consultant鈥檚 early involvement in modelling methodology can be measured in terms of both time and productivity, from the ease of preparation and agreement of area schedules, through to quantity take-off. It can also allow reporting on the consequences of design development in days rather than weeks, including the commercial implications of design changes or clash detection resolutions.

The project profits from aligned quantities, mitigated risk and the added benefit of genuine whole team working. The time advantage to the cost consultant allows more focus to be placed on 鈥渉igher value鈥� activities, such as advising on key implications of design decisions.

In terms of costs, cost consultants face many of the same upfront investments as designers 鈥� for example, they need practical BIM skills to produce visual information to demonstrate the cost plan and its basis, and to carry out detailed interrogation of models.

03 / Procurement

Tenderers need the model for a different purpose to the design team 鈥� for example, to enable them to commit to a lump-sum fixed-price offer within a short timescale.

In our experience, a project that uses BIM is attractive to tendering contractors and their supply chains.

On one complex scheme of above 拢50m construction value last year, high-quality BIM enabled the team to secure a robust and competitive single-stage design-and-build proposal (at a time when the market was, almost without exception, refusing such contracts), with the winning contractor stating that it would not have bid without this model.

Benefits that contractors derive from the model during the tender period include:

• Quicker understanding: ability to get under the skin of a project much more quickly within a limited tender period
• Scope capture: reduced risk of missed items and consequential difficulties post-contract
• Planning logistics: ability to plan works within a 3D environment, de-risking methodology and programme, especially for complex projects
• Communicating proposals: improved ways of demonstrating their proposals to the supply chain or back to the client and its team.

Contractors鈥� expectations around the content and data richness of the model must be managed. It is essential to build up trust ahead of the tender being released, and that this is maintained through regular dialogue throughout the period.

The above points will need to be considered in the context of different procurement strategies. For instance, with management forms, the management contractor or construction manager will have far more ability to influence the development of the model and could therefore generate a greater degree of trust in the model.

The BIM team at Alinea Consulting is headed by Richard Bates, Paul Zuccherelli, Richard Powell and Steve Watts