National BIM Library generic content release II - part two

BIM objects are as much about the embedded data and information as they are about the spaces and dimensions that they represent graphically. In the follow-up to his earlier article in Monthly Briefing Stefan Mordue, NBS technical author and architect, continues to look at the thought process behind the National BIM Library's next phase of generic content.

Consistent maintained data

We have added a rich set of properties for construction and facilities management that are presented in a consistent and structured manner. When considering the properties behind each object we included the following:

1. The IFC international standard property sets for that type of object.
2. The COBie UK 2012 properties that have been defined by the UK Government's BIM Task Group for Facilities Management.
3. Our own standard NBL properties as defined by our technical teams in association with trade groups.

IFC International property sets

Each National BIM Library objeEach National BIM Library object has IFC parameters embedded within it, the definitions of which have been obtained from the BuildingSmart IFC2x3 website. In the case of a shower object, for example, information includes data such as drain size, tray and shower type.

COBie UK 2012

Each component will at some time need maintenance, replacement or upgrade, and so attributes such as lifespan and replacement costs become beneficial when planning scheduled maintenance. Examples of this type of data includes details of warranties, start date, production year and replacement costs. The objects also include COBie parameters for which we have sought guidance from BuildingSmart. Through their work on COBie UK 2012, the objects will be updated in this and future releases, for example our Phase 2 content now incorporates parameters for accessibility, Code and sustainability performance.

When we consider installation information it may not be practical or necessary to add step-by-step instructions regarding the installation of a component. In many cases installation information is a reference to NBS workmanship clauses or the manufacturer's installation guide. Clearly this is not an ideal situation and highlights the importance of the depth of information contained within the specification.

Information to consider

NBL Properties

In addition to the IFC and COBie properties we have added our own NBL parameters. Data must be categorised and arranged so that it can be easily retrieved otherwise it is difficult to use - it is standard formats that drive the ability to use the data outside the BIM project file. In order for the information to be meaningfully re-used it requires a consistent set of parameters and attributes, with consistent naming conventions. As a bare minimum, a product can be identified by a trade name or model number. However, the NBL parameters provide a consistent set of attributes across all objects, giving information such as version number, issue date, NBS Uniclass title, section and clause number, and system outline reference. This work is backed up by a team of technical authors comprising architects, structural engineer, landscape architect and services engineers.

Relevant to the UK construction industry

As these objects are intended for the UK market, we have incorporated sizes, e.g. for door openings, that are typical of UK and British standards. We have added commonly available optional items that would often be associated with sanitaryware, such as enclosures to showers, screens to baths and gratings to cleaner's sinks. We have also looked at rationalization of how components are structured. In the past, objects have used the parametric nature of the components to have several sizes within one component, where others will have multiple components to pick up the different sizes. For example, multiply sizes for signage can be selected from one object. We have started to develop our signage objects with the inclusion of fire and safety signage. In determining signage sizes and taking into consideration observation distance we have referred to BS ISO 3864-1 and BS 5499-4.

Signage objects in a range of typical standard sizes

Mind the gap

Integration of specification into the building information model fulfils one of the greatest promises of BIM. Information contained within the model is not always relevant to the specification, and information within the specification sometimes has no bearing on the model. We do not wish to duplicate information and therefore what we really need is a bidirectional association between the specification and model to ensure consistency and enrich the objects. If we take our new floor finishes for example, the user may define the dimensions in their chosen BIM platform. However when we compare this to the specification we can begin to appreciate the level of detail that is missing, such as adhesives, fasteners, accessories, and that is before we have even begun to discuss workmanship, execution and system completion.

We can increase the overall data content without over burdening the original database, and it ensures that all project parties have access to the same core project data at the same time. We might not be there just yet, but watch this space!

And finally...

We will shortly be releasing curtain walling objects and adding more content to the landscaping objects. We have also taken comments on board from users and will be looking at good quality generic M&E objects.

Useful links:

nationalBIMlibrary.com
NBS Create
What does Building Information Modelling (BIM) mean for specifications?

 

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