topic Re: LOD 400 and more - what to expect? how to model? in Project data & BIM

LOD 400 and more - what to expect? how to model?

stefan — Mon, 30 Dec 2024 16:08:27 GMT

I am reading a bit on Levels of Development. So far, the two best interpretations of the "official guidelines" I read are:

bimfix.blogspot.com/2013/07/developing-lod-level-of-development.html

practicalbim.blogspot.com/2013/03/what-is-this-thing-called-lod.html

I mostly get it. I'm still looking at the best way to assess a model to see what the LOD is for Elements based on their geometry & properties (apart from having a manual attribute LOD with a number). However, I'm concerned about the following type of pictures:

Source: www.dynamicsofmasonry.com/content/level-development

Here, for LOD 400, it seems to imply that all individual parts, accessories, profiles, sheeting, etc... are to be included in the model. Is this what is to be expected from an LOD 400 model? I don't see it feasible in real-world projects above the size of a single-family dwelling and I don't see the need for it.

How do you manage this in projects? I can imagine ways to model it with ArchiCAD, but it doesn't sound like a smart way to model a design for as-built purposes nor does the owner will have much use of this.

Re: LOD 400 and more - what to expect? how to model?

Laszlo Nagy — Tue, 17 Nov 2015 22:20:12 GMT

I just came across another LOD specification source:

https://bimforum.org/lod/

They have just released their 2015 LOD Specification, which has a lot of tables and images in it. I found it useful:

http://bimforum.org/wp-content/uploads/2015/11/Files-1.zip

Re: LOD 400 and more - what to expect? how to model?

stefan — Wed, 18 Nov 2015 11:18:10 GMT

I have read this specification, but I'm wondering how far LOD 400 or even 500 assume you to embed in your model. E.g. would it be OK to have a plain ArchiCAD Wall with a Composite Structure with exact materials & thicknesses? Or will that not be accepted for this level.

In our region (Belgium), there aren't any national guidelines (we are helping preparing them, though), so it is mostly ad-hoc arrangements in construction projects.

Looking at the amount of elements and objects, it seems to indicate quite some detail that you may never model or have direct use for. E.g. the wall anchors are only indicated in principal construction details (2D often) and mentioned in the Bill of Materials, but not part of the model.

Re: LOD 400 and more - what to expect? how to model?

Laszlo Nagy — Wed, 18 Nov 2015 21:28:25 GMT

Unfortunately I am not that familiar with the process or what clients usually require in this regard.
I just thought that PDF could help you so I provided its link. I looked at it and found it would be useful for me if I had to do something like this in the future.
But other than that I cannot be of much help about this topic.

Re: LOD 400 and more - what to expect? how to model?

Steve Jepson — Thu, 19 Nov 2015 09:53:08 GMT

stefan wrote:
I am reading a bit on Levels of Development. So far, the two best interpretations of the "official guidelines" I read are:

bimfix.blogspot.com/2013/07/developing-lod-level-of-development.html

practicalbim.blogspot.com/2013/03/what-is-this-thing-called-lod.html

I mostly get it. I'm still looking at the best way to assess a model to see what the LOD is for Elements based on their geometry & properties (apart from having a manual attribute LOD with a number). However, I'm concerned about the following type of pictures:

Source: www.dynamicsofmasonry.com/content/level-development

Here, for LOD 400, it seems to imply that all individual parts, accessories, profiles, sheeting, etc... are to be included in the model. Is this what is to be expected from an LOD 400 model? I don't see it feasible in real-world projects above the size of a single-family dwelling and I don't see the need for it.

How do you manage this in projects? I can imagine ways to model it with ArchiCAD, but it doesn't sound like a smart way to model a design for as-built purposes nor does the owner will have much use of this.

I would love it if someone would pay me to design their project to LOD 300 or 400. I don't have any clients that would be willing to pay for it. Perhaps it is for Government projects where the cost of making the plans is easy to pass along to the tax payers. I do model to match this level of development quite often, but only for parts of the Building Information Model which need to show that level of detail in the drawings and details.

The data that needs to be extracted from the Building Information Model is not inextricably linked to the geometry in the model. We can extract it from 2D content as well so there is no reason for modeling to this level of development/detail that is necessary in a Building Information Model.

The thing is, BIM is a Process to the people who are finding a need to invent LOD Specifications. However, the Building Information Model does not need to be used in a BIM process to be of great value in producing the construction documents necessary to construct the building.

To me the BIM "process" is adding many unnecessary levels of complication and encumbrance like LOD Specs to the project for no good reason.

Re: LOD 400 and more - what to expect? how to model?

Laszlo Nagy — Thu, 19 Nov 2015 15:07:26 GMT

To me LOD 400 modeling is in the realm of Construction modeling so I would suppose for contractors/subcontractors/fabricators this would be feasible and profitable to do.

Re: LOD 400 and more - what to expect? how to model?

Steve Jepson — Thu, 07 Jan 2016 21:04:03 GMT

laszlonagy wrote:
To me LOD 400 modeling is in the realm of Construction modeling so I would suppose for contractors/subcontractors/fabricators this would be feasible and profitable to do.

And if it is not profitable - it will be government mandated soon enough anyway. I think we better get prepared for it.

https://bimforum.org/lod/
http://bimforum.org/wp-content/uploads/2015/11/Files-1.zip

I have a question about this - does meeting these LOD requirements mean modeling the entire project to a certain level, or only the parts of it that would be shown in a detail? The reasons I ask that is because there are more ways than modeling every brick to extract the total amount of brick needed from the model. Theoretically, there is no direct relationship between the data you can extract from the model and the LOD.

A much better solution than all of that UK government mandated IFC-IFD-COBie-OpenBIM-IDB-ISO-bSDD-CPS-BRE-CRAP would be to simply require that the construction documents be made as hyper-linked PDF's that contain all of the necessary information they want to evaluate.

PFD is already as close to a universal file format as you can get.
I am not talking about the kind of dumbed down pseudo .pdf's you can generate with ArchiCAD.

The kind of PDF I am talking about is like ones you can make with the Adobe Acrobat XI Pro for example. http://trials2.adobe.com/AdobeProducts/APRO/11/win32/AcrobatPro_11_Web_WWMUI.exe

Re: LOD 400 and more - what to expect? how to model?

Steve Jepson — Thu, 07 Jan 2016 22:55:58 GMT

stefan wrote:
...E.g. the wall anchors are only indicated in principal construction details (2D often) and mentioned in the Bill of Materials, but not part of the model.

I do put them in the model for the sake extracting quantities into an Interactive Schedule.