Demolition / Remodel techniques

[Anonymous]

I am fairly new to ArchiCAD. I am wondering how most people approach the problem of a remodel. Working in 2D it is very easy with 3D it seems that you would end up with a very confusing model. Any and all tips are appreciated.

Best regards - Chris

[TomWaltz]

The big keys are layers, intersection settings, and layer combinations.

If you model everything on corresponding Existing, Demo, and New layers, you can keep everything straight.

My personal ideal is that if something only shows up in one drawing, draw it in 2D. If something shows up in multiple drawings, model it.

[Anonymous]

I have done a lot of work on that area.
At first, I found it took a LOT of effort to put everything into 3D. Sometimes I was building stuff that would not be used, or would not be altered, like ironworks and stuff.
I doubted that it was worth the effort.
But this is what I found out:
Before we had computer aid, the classic approach to do some renovation project was first to go to the building, and spend a lot of time sketching its details. Not only taking photos, but actually drawing the various components, allowed you to integrate the building into your mind, to become very familiar with all its visual and structural characteristics.
Now, building it into the computer has the same results. You become intimate with everything about the building. This is great, because when you go to the next stage, which is trying out some solutions, you already have them pretty much nailed down.
To give you an example:
This building was not so great looking. It was very old and in an apparently bad condition, and just by looking at it you could not discern its intrinsic value. The client wanted some major work done, with much demolition, and I was inclined to agree.
After I modeled the building, we both found out that, taking away all the vegetation, grime and alterations, this was indeed a jewel. Therefore, the intervention was minimal, as we tried to maintain as much as possible.

So, now I always transfer the building into the computer prior to starting to look for solutions. And I found out that doing so is fun (yeah, I know, architecture - especially CAD - isn't supposed to be fun...).

[Anonymous]

This is what the computer gave us...

[Anonymous]

TomWaltz wrote:
My personal ideal is that if something only shows up in one drawing, draw it in 2D. If something shows up in multiple drawings, model it.

While it's hard to argue with this statement, one must really consider the project as a whole and everything from the desired result to its complexity. So...

Krippahl wrote:
Now, building it into the computer... You become intimate with everything about the building. This is great, because when you go to the next stage, which is trying out some solutions, you already have them pretty much nailed down.

Since you will be using ArchiCAD to communicate your intent as well as for problem solving sometimes having the existing building modeled can help the client understand what you are proposing and sometimes it can help a contractor as well. An example might be the picture attached which can be used to compare existing and new space or to let a contractor have a clearer idea of what needs to be removed. (demolition layer is set to show as wireframe in 3D)

Woody

[Steve Jepson]

cgorgas wrote:
I am fairly new to ArchiCAD. I am wondering how most people approach the problem of a remodel. Working in 2D it is very easy with 3D it seems that you would end up with a very confusing model. Any and all tips are appreciated.

Best regards - Chris

You probably don't need any tips on 2D methods for showning demo work but attached is a drawing with a squiggled custom line type used for the walls to be removed. This can also be used when you would like other parts of the drawing to look more hand-sketched.
Sometimes it's more convenient to just replace the line types of a quick 3D hidden line drawing than to render it in sketch mode.

[Anonymous]

I would agree that it is best to model the existing building in 3D, (it doesn't have to be very detailed, but walls, roofs, windows/doors.) You never know how much info you will need to provide to various jurisdictions; in the SF Bay Area most building/planning departments want either complete plans and elevations of the existing building or demo/existing areas shown on new plans and elevations.

We use the NCS layer standards, with ArchiCAD extensions of D, E or N. Using the layer extension allows you to sort in the layer list so it's easy to turn off and on the layers you need. You do end up with a very long layer list, but it can be very powerful with the layer combinations. YOu can easily show Demo walls in the floor plan view, but have them turned off in elevations and sections.

For remodels I put everything on the existing layer, then as we develop the plan split walls and then use the syringe to give removed portions a demo look and layer (probably possible with the favorites palette too.)

Hope this helps,

[Anonymous]

Good morning -

Thanks to all of you for the informative reply's. I am putting them to use now.

Best regards - Chris

[Anonymous]

I am working currently on a large project which is also as your americans call it "a remodel".
I was curious how you would best move the hand drawn existing building plans to CAD? Scan it in and trace over the existing drawings? Measure and draw? I am tring to establish 'best practice'.

[Anonymous]

patricprz wrote:
I am working currently on a large project which is also as your americans call it "a remodel".
I was curious how you would best move the hand drawn existing building plans to CAD? Scan it in and trace over the existing drawings? Measure and draw? I am tring to establish 'best practice'.

I would usually measure and build the model from my measurements. If the existing drawings are the construction set, then input your building model from the actual dimensions. I have found it useful to start my input from the structural drawings and then add the architectural walls. Closer to the way it would have been constructed and you can find and discrepancies from the architectural to the structural plans. If there are any you can be sure that the builder probably didn't find them until the structure was already in place.