Hello BIMfans,
After undertaking a traditional survey of my home last week, this week I have finally opened up a piece of 3D software and started to do some modelling!

First thing’s first; what do I need to actually produce?  Well, after reviewing my Master Information Delivery Plan (MIDP), and the responsibility matrix within my BIM Execution Plan (BEP), I need to produce an Architectural Model which includes:  External walls, internal walls, door, windows, roof, floors, fascia, gutting and anything else associated with the external structure or internal layout.  So to do this I need some objects, but it isn’t as simple as that..

First, I need to either find the right objects, or build them myself.  Now this week I have managed to build my own (so I won’t discuss online object libraries this week) but once I had built my objects I found that picking their names was a challenge!

Now luckily for me to make sure that good consistent naming was used I specified within my Employer’s Information Requirements (EIR) that BS8541-1 should be complied with; the British Standard for object identification.  Within this standard it states that objects using the software’s associated classification (Like when you use a Wall object to represent a Walls) should use three fields.

Source:
Source is easy, I made these objects so I have used the the same organisation code I used in my EIR & BEP; BBH (BIMblog.house).  However if they are downloaded from another source, then they should be identified as the source.

Type:
Type are also fairly easy as BS8541-1 suggests the use of the corresponding IfcType which can also be found on the IFC Schema page.

Subtype:
Subtype has little guidance but states that this information should not captured within the attribute data, so with that limitation I have used this field to describe the structure of my objects. For example, a partition wall object has the subtype ‘PlasterStudPlaster’, so describe the layers used within.

Note:  All fields need to use CamelCase (no spaces) and special characters are not permitted either!

Annoyingly many of the standard objects within the software package I was using (Revit) didn’t strictly comply as hyphens ‘-‘ are only permitted in objects without associated classifications.  So, after creating a number of my own objects, I ended up with a list like this:

Now that I have a consistent naming method, it’ll be easier to identify these objects when they appear in schedules and eventually within my COBie export.  So, to the modelling!

Those of you who follow me on Twitter, may have seen my frustration at modelling my home last night.  As my home is a 1900s Victorian Terrace, it isn’t exactly built perfectly straight.  In fact, when I tried to use a photograph to check my dimensions by course counting I discovered something very interesting; my courses don’t add up!

So sticking to my internal dimensions, and modifying some of my wall thickness to take into account imperial brick dimensions, I have started to create my graphical model. Currently Work in Progress, this model currently includes:

• Generic floor objects with a depth based on my landing void;
• Wall objects based on my survey measurements, and has started to be populated with bathstone detailing and render on the rear facade; and
• Generic roof objects based on pure conjecture (to be revised!)

There you have it, after some frustration trying to make my measurements add up, this model is now starting to look like my home.  However, this model isn’t complete by a long shot, so I hopefully by next week it’ll have sufficient content so that I can answer my current Plain Language Question, PLQ2.3.

Model Generation:
2.1 What existing information is available?
2.2 Is there sufficient information to produce a BEP?
2.3 What is the layout of the house?
2.4 What assets are contained within?
2.5 What asset information can be linked to the graphical model?

Now that I have started this model, it’s time to add some further objects, to answer PLQ2.3…