One of the main benefits of designing in a BIM environment is the use of object libraries, which allow for standard items to be re-used and repeated across the building. As with a ‘traditional’ library, each item in an object library must be easy to identify, so everything’s coded and classified into “families” and “sub-families” (such as “furniture” leading to “bedroom furniture” and “lounge furniture” or “doors” leading to “external doors” and “internal doors”) to further improve selection. This also covers items like the electrical cabling, mechanical ducting, windows and so on – it doesn’t have to just be stuff which can be taken with you when you move! These items can then be selected by the architects and engineers when they’re designing the building. Each item’s embedded information will also stay with it, containing details such as item size, material make-up, whether each bit is recyclable and/ or potentially hazardous to health and, of course, cost.
While this is all very interesting to those of us who like that kind of thing, this means that those interested in the price of windows, for example, will have a better idea how much glass will be used and roughly how that compares to the budget. Similarly, the architect can easily work out how much bricks would cost instead of a plastered frontage, wood cladding or pebble dash for our little block of flats. It also means that the architect can work out if the high-end self-cleaning glass in that massive feature atrium is within budget (it probably isn’t) or if some standard windows would do the job just as well for a fraction of the price (they probably will)
Using the data in the virtual model, the designers are able to work out how much carpet or how many floor tiles were needed for each room. Not only that, they could work out how long it would take to clean each type (so it could take 10 minutes to mop a floor or five minutes to hoover a carpet) which would help them work out how much the flooring would cost to maintain. So far, so good. But there’s more…
- If a carpet has an expected life of say five years and costs about £15 per square metre, the building owner will know that in five years they’ll need to budget about £240 to replace a carpet for a room that’s four square metres
- Similarly floor tiles might have an expected life of say ten years and cost £20 per square metre so our building owner will know that in ten years they’ll need to budget about £320 to replace the floor tiles in the same size room
- Taking these two prices (or more if you think about other options such as carpet tiles, wood floorboards, a more expensive carpet, vinyl or laminate, for example) will help the building’s owner work out the best lifecycle cost of the flooring
- And as if that wasn’t enough, the guarantee and even the receipt can be embedded in the virtual model, along with the all-important instructions on how to clean it properly and remove grass or ink stains. And if it’s guaranteed to last for five years and only lasts three, it’s easier for the owner to go back to the carpet supplier and tell them there’s something wrong
And it’s not just flooring. Think of the fan units in the kitchen and bathrooms, the oven, the fridge, the boiler, the TV… even how much the paint costs on the walls. And speaking as someone who’s just moved house, blinds and curtains, I wish I had this information (and that I knew why none of the windows in my house seem to be standard sizes!).
Creating the virtual model isn’t just about making sure all the pipes, wires, windows, walls and floors are all in the right places or to track costs and check whether things are recyclable or how to replace them; these models allow the designers to embed documents to items inside the model, which can then be accessed by those using (and crucially, maintaining) the building in the future.
This also means the building’s end-user can open the virtual model and the instructions for the fridge or the cooker will be embedded in the model and associated with the item, alongside the installation information, the guarantee and all those other important things that are in a ring binder in the loft, or stuffed into “that drawer” in the kitchen (or under the sofa). And of course this doesn’t just cover the fridge and the oven. It’s the same for the central heating system, the extractor fan, the hot water cylinder, the microwave, the television and any other things which need instructions.
Designing in a BIM environment also allows the designers, builders and end-users to capture and analyse performance data to drive more efficient operations and feed back into future designs. Yes, this might sound like overkill for a house, but think of managing all this information for equipment and other gubbins somewhere like a school. Or a hospital. Or a library. Or… again, the list is endless.
Of course there’s more to these models. They’re not just intended for the designers and the end-users or owners. They can also help the construction teams to work out if everything’s in the right place. The model can be input into an augmented reality model, meaning those on site can check that what they’ve built complies with what the designers intended – this can not only reduce errors on site, but can also help ensure compliance with building regulations and the like. For example, on some building sites today it’s not unusual to see construction workers wandering around carrying tablets rather than drawings. It’s also possible to put data from these models into virtual reality models, meaning those using the building in the future would be able to have a full virtual tour before any work has even started on site – in February last year, for example, Network Rail launched a ‘virtual’ version of Waterloo station showing how it will look once the old Eurostar platforms are converted to use by domestic train services. And just a few weeks ago, a virtual version of this year’s Serpentine Pavilion, designed by Mexican architect Frida Escobedo, was released by the structural engineers working on the project so the public can walk around it without leaving home. One of my team pointed out that it’s a bit like a Kindle, but for buildings.
last time: Part One — When, What and Why
next time: Part Three — Not Just Buildings