ill have a LOD500 model thanks

Further to my blog post the other week on questioning the value of Digital Twins I thought I would continue to put out some further concepts I have been questioning for some time and the excess waste that we as an industry are now creating, thinking it is for the greater good.

At the completion of construction now, clients are beginning to ask for LOD400, LOD500 as built models to be delivered as part of their information requirements. To achieve this outcome contractors and BIM authors are needing to allow in the price or fees the additional costs to produce this millimeter accurate virtual models. The process required to achieve this deliverable requires a party to laser scan the whole built asset at the completion, and depending on how strict the model requirements are, laser scans would also be required throughout the construction process to pick up services and structure that would be concealed by the time an as constructed laser scan is undertaken. Once the scans are completed the BIM authors would then perform a verification process to determine which elements have been constructed in accordance with the design intent models, and to edit the elements that have moved compared to the original model. Now these 2 x steps are not a small task and depending on the size of the project can cost a lot of money.

Why do I claim this to be a waste, so hastily? Well, most of the energy and effort in producing these models will be wasted, never touched, or used ever again. Maybe they will be used to create these fabulous interfaces to our BMS to turn things into Digital Twins!

Honestly, though these models are created and stored by the asset owner ready for the time when they want to renovate their asset in say 7 – 15 years’ time. There are two things I question with this type of asset owner, and their need for models. Firstly, will you be able to open the model in 10 years’ time? And secondly when you engage consultants to produce the design of your renovation, will you certify or take ownership that the models provided by you are going to be an accurate representation of the as-built asset, and you can save time and money in that engagement because accurate information is readily available. Sadly, I don’t think asset owners will certify that the information is correct, and the newly engaged consultant will need to allow in their fee to validate that the information is correct. Now people could argue that would be easy, you would perform a couple of checks against a few critical items rather than perform a full check. The problem with this method is that it will be the one thing you don’t check that creates a potentially big problem and cost the project significantly.

Why this huge push to produce accurate as-built models? The reason I think that this is being pushed so hard is because of the really poor quality of as-constructed drawings that have been provided by the sub-contractors and issued by the contractor to the asset owner at the completion of projects. The asset owner finds out how poor they are a few years into owning the asset when they rely on that information to only find out that they break open a wall and take out a whole electrical supply line when it isn’t where it was shown on the as constructed documentation.

So instead of sub-contractors doing their job and accurately documenting as constructed, we think we need to go to the extreme and ask for everything in a model. I think this is complete overkill and should be addressed with what is truly needed rather than going over the top and asking for everything.

“It is like going into a restaurant and rather than ordering a meal that will satisfy your hunger for the evening, you decide to order the whole menu!”

In the end, you won’t be able to eat all the food, and it would go to complete waste, and you would have to pay for all that waste. Doesn’t make sense does it? Now I am not against models being delivered. I am against models for models’ sake. Request only the information that you need to operate and maintain your asset. Depending on the asset type and the frequencies of change occurring to the asset, all the above is not excessive and 100% smart. But for asset owners that are not going to make significant changes to their asset for say 15 years, then why bother having a model delivery at all, when you will require the renovation consultant to capture accurate existing conditions anyway? Think about the financial savings you can make if you don’t pay for excessive scanning. Every $100 you save today (at 3% inflation) in 15 years’ time you would have saved $157. Taking into consideration the costs of capturing information is only getting cheaper you may find this economic outcome even better, maybe the costs of scanning will be say, 75% of the cost it is now. I do think it will be exponentially cheaper than this but let’s be conservative. So, $100 worth of laser scanning costs $75 in the future, and your $100 not spent converts to $157. You end up with an additional $82 in your pocket in 15 years than you would have had had you spent your money scanning now. And with people probably scanning now and in 15 years because they don’t trust the data, they will be $175 out of pocket rather than having the $82 in their pocket.

Closing this out, as stated I am not against laser scanning and models for as constructed. I just think that you need to be thoughtful in your menu order. Order only what you need, don’t order things just because you can, it means you are paying for waste, and not paying for a better quality built asset. 


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