Saturday, March 21, 2009

conTENT with CONtent?

Now that BIM has stared to become widely accepted, and viewed as a necessary component of the AEC communities, the responsibility of providing product models is starting to lie in the hands of the manufacturer. Just as a manufacturer must provide Specs and CADs today in order to be competitive, tomorrow holds the requirement of BIM models. So what does that mean, "BIM Models". Some providers may lead you to believe that simple images are all that you need, but from an expert in this field, the requirements of BIM are "expanding exponentially". Thus far, the "i" in BIM is largely unexplored by content providers and certainly treated as lower case and subordinate to the "M".

The bar has been raised by those who create "Super Families" that are not only high quality graphics without sacrificing modeling speed, but contain appropriate data and family nesting to allow for high powered scheduling and maintenance study and analysis. In my humble opinion, without appropriate descriptions, proper attributed data and takeoff abilities of a BIM product model, it's about as useful as socks on a rooster... while entertaining to watch, actually makes more work for everyone.

When looking for a content provider or creating your own, there are several things to consider. Below is what I believe to be the bare minimum tht should be contained within a BIM Object.

  • Lipstick on a pig... Graphics need to be accurate and consistent with the intent of the model without slowing down the model's performance. If you put a $5,000 paint job on a Yugo, it still will only do 55, and if Kwik-Lube tunes your Ferrari.... well, you see where I'm going here. This delecate balance needs to be managed properly. Fixtures and fittings tend to be very graphic in nature with a lot of complex curves and angles. This level of detail detail can slow down the model if not done with some care.
  • Size matters... Dimensions need to be accurate enough to consider tolerances and clash detection. Most electrical devices are created considering only the visual aspect and (Hopefully) the MEP connector, BUT, an electrical device has a box embedded in a wall thats about 2"x3"x4". Adding a simple solid behind a wall plate will allow that device to be considered a clash when a 3" DWV runs right over it inside of a wall.
  • NO IMPORTS!!! - And no, I'm not talking about outsourcing graphics to Asia or South America... Imported CAD files converted into BIM files are large, slow and cannot be modified. Sizes cannot be modified, and proper rendering of these files is not for the novice or impatient.
  • It's not you, it's me... Data needs to consider not only those persons placing the information in the model, but those using the model later. In addition to baseline information about the identity of a product, performance aspects are used for energy and structural analysis; product lifespan is used for future budgeting and sustainablility analysis.
  • Fill in the blanks... This is an enormous pet peeve of mine that I see all the time. The description parameter is used for callouts. Materials or objects that have no description or one thet's too long or too short have a worthless callout. This is really irritating to the user when they need to go back and add this during the detailing phase.
  • Tell 'em what they've won, Link - Links to useful information like code compliance, specs, product data, installation procedures and sales and marketing can really simplify the research aspect of product selection, by creating a singular point of reference to search from. NOTE - If the manufacturer cannot ensure that URLs won't change, data MUST be linked through a library that will.
Family Nesting...
  • More than a simplified processes... Nesting families allows more than resueable components like door slabs and window sashes. It allows for option selection and more accurate scheduling and data management, especially for the FM folks.
  • What are my options?... Nesting families allows multiple components of the same type to be selected as options. Doors may have hundreds of slab (or leaf) styles, but all of them come in the same sizes. The slab becomes a "Nested" component that can be "Swapped Out" by the click of a dropdown.
  • Mother always told me to share... Shared nested families allow scheduling to be made more accurate and allow for mainenance components to be their own entity with their own attributes. Lets take a light fixture... The Housing of a Recessed light is a durable product with a lifespan of 20 years. the ballast and bulb are 2 components that are both components that will not only require replacement, but have options to select from. Nesting the ballast and bulb within the light fixture allows the ballast and bulb to have independant lifespans and installation dates for every light fixture installed. The FM team can see when every bulb and ballast was installed, and when they'll need to consider replacements.


  • No do-overs... This one's a no brainer, but I always find myself needing to say it... If I can't modify dimensions without going into the graphics, there is something wrong. Appropriate dimensions need to be made parametric so when updates need to be made, it's not back at the drawing board.
  • More than dimensions and materials... can be parametric. Equations can allow results based on other attributes. Calculations that determine if and where in the country a window meets ENERGYSTAR are created based solely on the input of a U-Factor and Solar Heat Gain.

I hope this has been an informative post and can give some insight as to what you should expect... no, demand... from your content provider. Content is being treated as something like BIMs read-headed stepchild, but the bar is raising on the level of detail required in the model. The needs of the architect are beginning to demand that content developers step up to the plate and take their BIM content seriously. The main difference between man and other mammals is the opposable thumb, and most of us choose to use it. The difference between CAD and BIM is the data... Let's use it... Don't settle for less, and don't just be conTENT with CONtent.

Monday, March 2, 2009

The Devil is in the Details

So you have this great BIM Project that has solid graphics, a respectable level of data and attributes, and all-in-all has saved you time in design. What about the drawing sheets? How much detailing work are you doing manually, and how many of your termination, intersection and other construction details are from the ACTUAL MODEL? Seems like dumping dwgs of manufacturer details onto a drawing sheet is a common practice, rather than creating the sections and drawing in the linework. Why is this? Likely it's because of the lack of detailing that is done in Families and Objects, as well as the lack of attention to materials, which ultimately drive the callouts.

The Details...

This is another issue for my style guide. Detailing associated with families should be a part of the family, so that when it is placed within a wall, the linework in section views will show up appropriately. This in itself has its pitfalls and limitations. The window goes into a wall, and has no knowledge of the type of wall, so how can the detailing be done? There are detail families which can be imported into the project file, and plunked down on the Drawing Sheets which are a good idea, since the detailing really is only important on the drawings not in the model itself... Right???... Not so fast. Yes, the detailing is only viewed on drawing sheets, but the detail should be dependant of the window, not of the wall, since the window is inserted in the wall, the wall is not placed around the window. What happens if someone wants to make a new wall section at a window... You'd need to drop in a new detail family with it as well. An instance parameter of Type - Detail Family could be nested to allow different wall type connections (Wood, Metal Concrete, CMU) to be swapped out on the fly.
I'd love to create hosted families that are more intelligent, like opening family attributes which apply to all openings of Host Type (Wall, Floor, Ceiling, Roof), so if you punch a hole in a roof, it will intuitively place base flashings, or flashing tape associated with a window. These can all be created as "Families of Type" or "Material" Instance Parameters to allow products to be swapped out without swapping out the entire family.

For instance, a window manufacturer requires that Flashing Tape be installed around their windows. If a Material Parameter named "Flashing Tape" is created within the Window Family, you can swap out the type of material by updating the material name, or importing the material from a manufacturer of Flashing tape. This works well, gets the window specified, its installation specified, and opens the door for other manufacturers to be specified alongside the window. Taking it a step further, instead of a material parameter, a Family of Type Parameter can be added to insert an entire piece of graphics and layer of information which applies to the flashing tape. Basically, create a detail family for the Flashing tape, but add the attributes and values for the product itself. Let the detail family carry information as well as graphics for a product. This allows not only a Material to be specified alongside a window, but a Product to be specified. If a competitive product wants to be specified as an equivalent, their detail family can be loaded in the window family, and voila... new options to choose from.

Now this Brings me to Materials...

Materials are the Readheaded stepchild of BIM, and it irritates me to no end. Materials are the common ground of everything built, and every material has it's specific properties that make it what it is... nobody specified "Gypsum" or "Wood". They'll specify [5/8" Type X Gypsum Wallboard meeting or exceeding ASTM Somethingorother] or [3/4" FAS American Cherry S4S] even the finish on the wood or the paint on the gypsum needs to be called out, because Someone makes that product and there are more than one set of performace characteristics for a given product. That's where inferior and superior products come from. a BIM can't calculate the VOC levels of paint if they're not listed in the material... why would anyone want the BIM to calculate VOC's of Paint??? Because it can!