Sunday, 13 November 2011

Draft Revit NBL Content – Review Part 5


Jumping into Part 5 of the Review and I’m feeling a bit like Agent Mulder out of XFiles.


But what I’m really looking for is proof (so was Mulder get the link!) that the National BIM library will ultimately prove both useful and actually worthwhile using and adopting in someway, shape or form. Only time will tell.

Lets look a the terms used in building the description of the internal walls

Blk              Blk = Block
DryLng        DryLng = Dry Lining
Cavity         Cavity = Cavity
Int …………Internal
Insul            Insul = Insulation
MF               MF = Metal Frame
PF               PF = Partial Fill
Steel           Steel
Timber        Timber
TwinFrm     Frm

Well there are only two additional terms used and those are

Int for Internal and TwinFrm which actually just has highlighted that I have been bolting the terms for steel and timber together with Frm for Frame

So Add Frm = Frame to the ultimate list.

Can someone please explain to be what a “Twin” Fame is because looking at the make up of the wall, I’m not getting it? I expected to see two skins of Stud work with an air gap – you know like a Party Wall construction.
The next thing that strikes me is that there is no description for Party Walls yes they are Internal (well most of the time, apart from the external ones as defined under the Party Wall etc Act 1996) but they are special type of internal wall in that they have unique requirements with regards to the Building Regulations in terms of density and sound transmission these walls need their own identifier.

So I would suggest they are given one.

There are an awful lot of different wall construction missing from the examples provided. The NBS have not asked for users to help them establish a catalogue of typical wall construction used from Victorian times but they should do and ultimately make a complete practical set of System Walls for Revit and if they are going the IFC route then in that format as well.

Where are Victorian Solid Brick walls, the 1950’s and onwards Brick Open 50mm (2”) Cavity and Brick Party Walls etc?

On the subject of Bricks take a look at the width of a brick 102.5mm, Engineers would say Yes, Students would say Yes, Architects would say 102, 103, or 105mm, and so would all the block manufactures in their published work on U-Values.

It's clay and baked, the likelyhood is that its all those dimensions somewhere in the wall. This points to someone not really yet in the construction industry i.e students building the data for these families.

The list of UK Wall Types applies to the UK and construction industry and not just Revit and is a list of constructions and is thus platform neutral.

Regarding the “I” in BIM in and ability to put Crap in and get Crap out, why inflate the family with COBie parameters that are of no interest and more importantly use within a family. There appears to have been no thought given to this, one expects an answer “Oh well we  were just showing that we can add parameters”, yep we know that!

As I’ve asked previously some one please look at the list provided in the NBS document nbl_WallUserGuide.pdf and actually explain which parameters are actually applicable to walls and why this information is of use, because I just can’t get the penny to drop on that one. It looks like information for information sake to me.

Taken from nbl_WallUserGuide.pdf

The following COBie parameters have been added to each wall family to be populated by
the user for producing COBie data schedules.


Carl Collins of Arups presented the Geeky Side of Revit “Accurate Calculation of Embeded Carbon and Energy” at the Inaugural Meeting of LRUG on the 17th March 2010

He took data from Inventory of Carbon & Energy (ICE) Version 1.6a by Prof Geoff Hammond & Craig Jones published by the University of Bath, created a parameter eCO2 added values to parameter for elements and showed an example of creating a column schedule and having the ability to determine the Column eCO2 in the schedule, and then framing eCO2 in a schedule, then the Slab. He then showed how that data could analysed and used.

That is truly useful information and worthy of including within the I of a BIM model and more importantly is in line with the governments ultimate aims with regards Carbon, not what is the barcode for a brick, plasterboard etc.

So as the limited time for review comes to an end...... there will be no more until the next release of material from NBS.
Strapline "The National Building Library - I Want To Believe

Cue Xfile theme music for the outro.....


Mike Lister said...

Hi Alan,

Have really enjoyed reading about your feedback on this. I only found out about the NBL yesterday and wouldn't consider myself a geek as there is still a lot I don't understand. It seems from reading the LinkedIn comments that if the very knowledgeable guys like yourself are struggling there may not be much hope for the rest of us. I will be following your further feedback with interest.

cadalot said...


Nice to hear that you enjoyed the blog. We are all on the learning curve somewhere, I just think we need to help each other up the hill.