What is this BIM thing anyway?
Building Information Modelling (BIM) has been around for a while, at least 15 years or longer in the US and over here for a few years. BIM brings with it lots of new phrases such as BIM Model, Revit Model and Scan to BIM. The UK is technologically under the advancement curve from one perspective and partly dysfunctional in our holistic appreciation and approach to economically and sensitively designing, constructing and managing buildings and their wider infrastructure. In an age of increasingly sophisticated 3D survey data capture and visualisations there is still a huge downgrading of data to traditional simplistic 2D formats in order to satisfy historical requirements and preserve the status quo.
The current UK Government Initiative is driving wider industry professionals from across the board to comply with its suggestions/demands on a steep “BIM” learning curve of enlightenment. This will require investment by all those involved in terms of both capital and time to take-up in order to reap the benefits later. Paul Morrell, the UK Government’s former Chief Construction Officer, has several times publically told the wider construction industry to use technology to the full and “collaborate”- something we British are a little bit reticent to do most of the time. BIM is therefore becoming a euphemism for construction efficiency and green credentials through the vehicle of sharing information.
Of course it’s a fairly big enticement to take-up BIM since all Public sector projects coming in at £5m+ will be required to use the standardised BIM structure methodology which its Task Group has helped to construct- with carrot and stick in perhaps not equal measures. More enlightened private companies however, are already making the connection and leap of faith and making the move over to BIM as their mainstream focus. .
BIM: Son of CAD & GIS (Kalinkski 08)
BIM is greater than the sum of its parts and has traditionally, or currently in the UK, been wrongly thought of as a method for ensuring all design data is delivered in 3D with a building model. Whilst this sounds logically truthful, BIM is in fact a new way of working and more importantly of thinking. It’s a holistic, collaborative process of collecting and Managing Intelligently Modelled Information (MIMI) using the vehicle of various software suites.
There is a real infrastructure or building model, or realistically models, at the heart of the process but it is fundamentally database driven and “intelligent”; combining the best capabilities of both the GIS world and CAD software in a 3D environment. As Art Kalinkski (August, 2008; Geospatial Solutions) calls it “BIM, Son of CAD & GIS”. He cites CAD as dealing with points, lines, polygons and the quality of data and often focusing on the inert and visual. Whereas GIS is a topological model that’s linked to a database where each feature can be attributed and “knows” what is next to it and where and so on and so forth.
Internal Scan Data
The benefit here is that within the model, features can be quantified, measured and globally changed within the greater model as a whole. So for example a new type of door or window can be replaced with another type of different dimensions and characteristics and the model will update all occurrences and their associated structural openings etc. This of course makes model iteration, or trial and error, a whole lot easier and quicker.
So what is BIM used for?
The current government envisages that the vast majority of its projects will be BIM based in order to drive through their efficiency targets. But of course the likelihood is that this will easily spill over into a high proportion of private initiatives as two-tier multi-method working is something that none of us like doing. The pitch we are given is “think global, act local” and start with our own small BIM and aim towards being a part of Big Bim. This means working on projects in a “BIM format” which form part of a greater whole programme which considers infrastructure and continual joined-up thinking. You can see the worth in principal, but I think the move to the Goldilocks state of just right will be painful because of entrenched ideas, new methodology uptake issues and legacy methods and data.
3D land & Building Model
What Value does it add?
The bottom line is that BIM is supposed to generate transparent and tangible mid to long term benefits, any short term gains I would suggest being cancelled by the steep learning curve and investment needed for uptake. So what are these value-added benefits?
The value for design teams and beyond into facilities management is the database driven model which intelligently quantifies attributes and features allowing a wide variety of useful manipulations and quantifications by different professionals working on the project. For example “iterative virtual design” methods are made possible and can be employed which are highly cost effective. This method ensures a greater degree of fit between trial design models being balanced with practical construction considerations and also the reality of building management through these designs being road-tested for bugs by a collaborative team in the virtual environment before groundwork on site even commences.
One quick way of efficiently standardising the “model” content is to adopt the “scan-to-BIM” methodology of laser scanning existing features and buildings and producing point cloud data- thus ensuring that an accurate and robust data set is used at source to add to or create any BIM model. The benefit of this method is that a high degree of detailed subject data and also peripheral scan data is quickly collected in one go. This data may not necessarily be utilised immediately but once collected it can be used at a later date for other aspects of design or iteration or simply visualisation.
External Scan Data
Internal Scan Data
Since BIM as a process has a detailed model at its heart, the visualisation aspects of the methodology are wide ranging; from teams being able to easily appreciate a particular complex construction design in a video digital form as opposed to 2D plan drawings through to experimenting with landscaping aesthetics and building views and building outlook visualisations. These later points are vital for project approval in terms of getting stakeholders buy-in and also for stalling possible protests against the “non-sensitive fit” of certain buildings or architecture within an existing area. Right of Light issues can also be addressed at this early painless stage of development in a proactive manner, thereby removing the need for post construction back-tracking on any discovered legal position.
In addition to this “collect-once-use-many-times” benefit of scan data, the additional project value of as-built scan data being added to existing data sets is a relatively simple and highly effective process. Thus as a development progresses, for instance, it is easy to use the BIM model as a vehicle for on-going and updated programme management. This can be thought of in terms of comparing the design model at a particular stage of development with the “actual development” as analysed in the as-built data model. This method is currently being effectively employed on some very high profile works at a London airport for example.
What are the drivers?
Firstly the key driver is the public sector mandate for projects to be undertaken using BIM methodology. There is also the strong likelihood of overspill of BIM into private sector operations, which means that in order to continue to supply data to the vast majority of projects (over time) there will be an element of having to keep up with the Joneses in order to stand still as a data provider.
Cut away model
BIM has been used since the early to mid-nineties in the US to reasonable effect if you believe the posts. The software companies, albeit somewhat altruistically, seem to be trying to also grasp the nettle of development by focusing on BIM software development and the whole scan-to-BIM environment. Some of the key players such as Bentley, Autodesk and ArchiCAD are all keen to keep up with their new releases and show good willing to their growing “captive” audiences. I guess that this could at the very least suggest that software companies think this isn’t just a passing fad but actually worth the long term investment it appears to be making.
So What is the Next step?
Well, given that unless there is a serious government and construction U-turn in the coming couple of years then BIM is here to stay-though even without government intervention there is still arguably sufficient impetus already to probably counter any official tap being turned off. With the advancement in the scan-to-BIM process and methodology and its apparent worth and benefit then this is highly likely to be the preferred way of working and receiving information in the near to mid future. At the same time the whole holistic BIM methodology and the data capture process will both begin to percolate down the user tree to reach the majority of development projects and design and construction users. As the geospatial data becomes more transparent to all users then wider “BIM”, as a work method, will no-doubt become our mainstream business process?
Thus it’s probably time to try it out and also consider what long term investments are needed now in order to facilitate future use considering how steep and long that the effective take-up process will take time, along with the necessary investment- in these cash scarce times.
At Technics Group we are collaborating with a number of our clients to help each other through the implementation of BIM. We recognise that for our clients to effectively run a project using BIM the survey data has to be compatible from the start.
We are more than happy to be used as a sounding board and to be involved with our clients on their BIM journey so please do contact our Survey Director Martin Penney to discuss how we can work together.
BIM using Revit