Thursday, June 14, 2012

House Framing, the Digital way

Framing is rolling along well. We've got all the main walls up and the interior partitions went in the other day. We've got second floor materials being delivered tomorrow and then up we go!
Carrie framing out one of the big windows

Jason working on the interior of the double-stud walls

While I have lots of good photos of framing I'd love to post, I thought I'd take some time and talk about the digital design process we used while designing the framing a bit first though. We used a digital 'Building Information Modeling' (BIM) software package to design and document the house and we are trying to use this software to manage our information as much as possible. 

The full BIM model of our little cabin

While I like working in the BIM world and there are a lot of nice documentation tools in the product we're working with, I'm especially interested in the capacities of the tools to streamline and manage the crazy amounts of information in a project (even one as small as a little cabin). In parallel with large-scale design decisions, we used the software to sort of 'pre-build' the structure - allowing us to make all (we hope!) our mistakes in the digital model first and streamline the building process.

Column and Beam 3D model

As part of this - we developed a comprehensive framing model of every piece of the house. While this is overkill for most projects and not exactly 'built-in' to the software - we were able to turn it into a pretty good  framing management tool. 

(Disclaimer - some of the following is going to be a bit nerdy) We started by creating our own suite of families within the structural discipline for all our framing members, including columns, LVL and steel beams, studs, headers, sills, etc. These families were created to allow us to manage information like count, cut length, ordered unit length, placement and phase, etc. The main structure includes lots of engineered-lumber columns and beams - we set up special filters to allow us to isolate elements within the software to facilitate viewing and management. 

The full framing model with all the studs, rafters, joists, etc.

The above image is of the full framing model. We modeled as much as we could - the colors correspond to different 'phases' of the build so we can easily see what's going on and where. By going through the process of digitally framing the house we were definitely able to work out some of the more complicated areas. This model then feeds directly into the framing plans we have been using on-site to build the project. Below is a screen-grab of the framing plan and you can see we've worked out corners, Rough-Openings and all the relevant dimensions ahead of time. This is super useful to us since we knew we'd be the ones building this thing so it made sense to try and work out as as much as possible ahead of time. By also fully modeling the plumbing and HVAC system as well we are able to identify conflicts and modify the structure way before anybody is down in the basement hacking out chunks of important beams so they can run their ducts (Yes - that does happen!)

Close up of the first floor framing plan

While all this visualization and modeling is great and fun - its not really anything that can't be done with good-ol' pen and paper. The real exciting thing is the shot below!

Yes - I know, it looks like a spreadsheet - and it is. But to those of us in the construction management world this is gold. Because of how we built the framing-member families we are able to itemize and record all the material that goes into the final building. There is all sorts of good stuff here: Counts (of course), where and for what the member is used for (Headers, sills, studs, etc), and best of all cut-lengths and ordered unit length. The category for 'Is Nested' allows us to take the small pieces (short cripples, sills) and nest them in large pieces of lumber. This way we can be super efficient with our material ordering (especially important for us cus' we're out on a special project and don't have a shop to store extra material or anything like that). This info is accessible on-site so when someone asks: "Why are there so many 2x6's" we know exactly what they are for. 

Close up of framing keys and schedules

All the members have unique identifiers as well and so we have a series of 'Key-plans' showing locations and schedule info of every piece of wood that goes into the building. While I know there are lots of wood-framing specific programs out there that can kind of do this for us - I really like the flexibility and control allowed by building our own system. And, of course, control is what its all about. 

I hope that wasn't too wonky for you - and for those of you who just want to see pictures of us building stuff, don't worry - there's lots more to come soon.