As Built for FM - How to model?

We have been approached by a museum to model their building in 3D.

Their goal is to take all drawings and consolidate them into something managable and reliable. In addition to having a coordinated set of as builts, they are hoping to leaverage BIM capabiliities for some maintainance and FM. The model will then be used for any future work reducing the need for re-surveying.

This isn't too much of a problem in theory. The reality is that the current drawings don't really give much of a clue as to what is going on vertically. They look like decent plans but when you come to trace over them, you ask yourself "what is that? and why does this wall look like it was concieved by Escher as the inside face becomes an outside face!":shock:

The size and complexity of the building is scary. They want me to make "something simple" and refine it later as we go. I like to model accurately from the ground up but it looks like I'll have to be flexible in my approach. Some walls are irregular shapes so I guess I should use in place families to mass'em out although I would hazard a guess that it's non parallel dry walling. The worse part is that columns don't line through on each level. 2D drawings are brilliant works of fiction and Revit doesn't blag!

Anyone got ideas for work flow and client approach for working up an as-built model. It's due to the lack of understanding about modelling that is hurting. I was asked to just do plans and not worry about elevations for now!

Might be an opportunity to partner with someone to scan the building with a Laser and consider the Scan to BIM tool? That would give you a very accurate point cloud model. Then Scan to BIM would convert things into a Revit format...

I have infact looked into that. I trialled the scan to BIM plugin but it doesn't run smoothly at any reasonable point count. I had to limit it to 700,000 points for a very jerky experience and it was practically unusable. I have experimented with Pointools and it is a smooth ride with 30 million points! It looks practically solid which is what you want. I wrote an email about the scan to BIM but got no response.

However, I'm ever hopeful that Revit 2012 will support point clouds since autodesk software seems to be taking it up and AU demonstrated it in a keynote. Lets hope it makes it to the next release. The issues for point clouds are two fold for us-

1. We can't wait till April :(
2. My boss doesn't want to lose the fees for the survey! ;)

I'm not sure how easy it is to model up from point clouds. I was hoping to not model at all and perhaps use a point cloud as the as built, just adding to it from there on but I'm told to forget about it :cry:

Any advice from a traditional BIM point of view. How dow I communicate to the lay person that a model needs care and attention and that shortcuts will not offer value. Should I model is stages? How should those stages be divided up in terms of the model?

My main concern is that if we start with just a room, how easy is it to expand out from it. Do I bind a link into a new project or just try adapting it?

Should I be concerned about it biting me later or will I be able to muddle through. Defining levels can be so important and not taking a holistic approach makes it very difficult.

Cheers

Laser scanning is nice, but you can just draw it IF you have access to the original drawings and any alterations made since. I am currently building a model of a 13 story building built in 1954. It's working very well, and the results will be very useful for the owner.

Also, Revit units will work very well for you. Chances are original drawings were drawn in Imperial units. You can draw in feet and inches then change the units and you will immediately have metric.

When I was in the UK I drove everyone crazy because I had a US tape measure. Things that measured 609 were an even two feet. Much of the British infrastructure is in Imperial. It will be a good workout.........:lol:

I am doing a 14 Story Hotel, that has many additions and alterations. Plan old Revit works like a charm, just need to know how and when the building additions were constructed.