Seperate phase for Demo - Why?

[jwinkler8A6WX]

Can someone help me understand why so many firms insist on creating a separate phase called demolition?  I have always understood this to be a mistake/mis-use of Revit, but maybe there are good reasons that I just don't know about.  Does anyone do this - or understand why?

I know for a fact that rooms in past phases cannot be shown in the current phase - causing the need to make multiple copies of existing rooms.  Design options, temporary infills become a nightmare etc.

[RobDraw]

I totally agree that demo is a separate and distinct phase. Just because a program suggests it should take place in a phase doesn't mean it happens in the same phase as new work. The construction process has had a demolition phase since before Revit. Some people don't use Revit's demolition tool for a variety of reasons and opt for a demo phase.

[jwinkler8A6WX]

I see your point.  And in CAD it always warranted a separate layer.  So maybe in good practice then, one should not manually name a phase "Demo,"  because "Demo" is actually a sub-phase automatically built-in to every Revit phase, and it cannot be re-named.  It causes great confusion when using the View Phase Filters which say "Show Existing and Demo" or "Show Demo and New."  Those built-in filters are not actually talking about manually named phases, but inherent "sub-phases."  Therefore, maybe it should be an unwritten rule to never name a phase "Demo" but call it something else like "Construction Enabling" or "Pre-Construction."

[RSomppi]

That's a matter of opinion and would vary from place to place. When I use a demolition phase, the demolition tool is not used. Phase filters are set-up accordingly and all users are aware of the proper workflow. No need to stray from established norms just because a program has something else with the same name.

BTW, unwritten rules don't get followed consistently. Especially, by lower level users. It's sometimes hard enough to get them to use the written ones.

[ToanDN]

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@jwinkler8A6WX wrote:

I see your point.  And in CAD it always warranted a separate layer.  So maybe in good practice then, one should not manually name a phase "Demo,"  because "Demo" is actually a sub-phase automatically built-in to every Revit phase, and it cannot be re-named.  It causes great confusion when using the View Phase Filters which say "Show Existing and Demo" or "Show Demo and New."  Those built-in filters are not actually talking about manually named phases, but inherent "sub-phases."  Therefore, maybe it should be an unwritten rule to never name a phase "Demo" but call it something else like "Construction Enabling" or "Pre-Construction."

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That is not a good practice for Architecture and Structure (additional coordination efforts since existing and new are now disconnected).  I can't speak for MEP.

[jwinkler8A6WX]

Either way, the confusion is coming from the word "Demo." "Demo" in the View Phase and "Demo" in the View Phase Filter mean 2 entirely different things.  This is coming from 15 years of trying to explain to users, MEP and architect alike, how to fix the graphics settings for a demo plan.  I've worked at 6 different companies, and nobody ever seemed to understand it.

I am setting up a linked background today where the architect created 3 phases....."Existing", "New Construction", and "Phase 2."   Views are set up as follows:

View Name :                       Phase:                                  Phase Filter:

Demo Plan                          New Construction              Show Previous + Demo (most demo'd walls are here)

New Work Plan                  Phase 2                                Show Previous + New  (there are also demo'd walls in this phase)

I apologize if I gave anyone a headache, but..........do you see what I mean?   It's confusing enough!!!!  Let's stop using "Demo" or "Demolition" as the name of a phase.

[ToanDN]

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@jwinkler8A6WX wrote:

Either way, the confusion is coming from the word "Demo." "Demo" in the View Phase and "Demo" in the View Phase Filter mean 2 entirely different things.  This is coming from 15 years of trying to explain to users, MEP and architect alike, how to fix the graphics settings for a demo plan.  I've worked at 6 different companies, and nobody ever seemed to understand it.

I am setting up a linked background today where the architect created 3 phases....."Existing", "New Construction", and "Phase 2."   Views are set up as follows:

View Name :                       Phase:                                  Phase Filter:

Demo Plan                          New Construction              Show Previous + Demo (most demo'd walls are here)

New Work Plan                  Phase 2                                Show Previous + New  (there are also demo'd walls in this phase)

I apologize if I gave anyone a headache, but..........do you see what I mean?   It's confusing enough!!!!  Let's stop using "Demo" or "Demolition" as the name of a phase.

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As I already said I can't speak for MEP but since you are giving an example of Architecture, allow me to comment that it is only confusing to users because you deviated from the OOTB phasing system of Revit.

From the architectural modeling standpoint, what benefits would you get from the additional 'demo' phase?

[jwinkler8A6WX]

You're preaching to the choir.  I never believed in demo as a phase, because I started in Architecture and saw the nightmares caused by that.  But that's why I asked my original question.  but I'm hearing that there are very good MEP reasons to keep demolition work on it's own phase.  I am trying to understand and learn them.  I'm  just saying don't name the phase "Demo" or "Demolition."  -too much unnecessary confusion.

[RobDraw]

No, Revit has deviated from established norms. In Revit, demolition is state of being that happens during a phase while we have always considered demolition a phase in itself. Forget about the terminology ever getting "fixed". Just use more words. Revit demolition and demolition phase should do the trick. If you're using demolition phases, it's probably not necessary to use Revit demolition. If you use Revit demolition, you don't need a demolition phase.

[ToanDN]

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@RobDraw wrote:

No, Revit has deviated from established norms. In Revit, demolition is state of being that happens during a phase while we have always considered demolition a phase in itself. Forget about the terminology ever getting "fixed". Just use more words. Revit demolition and demolition phase should do the trick. If you're using demolition phases, it's probably not necessary to use Revit demolition. If you use Revit demolition, you don't need a demolition phase.

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Blue statement is correct.  Red is not.  You can't avoid Revit demolition whether or not you are using demolition phases.  If a wall needs to be demolished then its Phase Demolished must be assigned to a Phase, you just move that value from one phase (New Construction) to another phase (Demolition).

[iainsavage]

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@jwinkler8A6WX wrote:

 "Demo" is actually a sub-phase automatically built-in to every Revit phase, and it cannot be re-named.  It causes great confusion when using the View Phase Filters which say "Show Existing and Demo" or "Show Demo and New."  Those built-in filters are not actually talking about manually named phases, but inherent "sub-phases.

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They are not sub-phases, they are states.

Existing means existed before the current view’s phase - doesn’t matter which phase they were created in, if they existed before the current phase then they are Existing (as long as they’re not demolished). You could have ten phases, anything created in any of 1 to 9 would be classed as Existing in phase 10.

Similarly Demo means the item is in the demolished state.

New means the item is created in the current phase, regardless of what that phase is called.

The key is the order in which the phases occur in the phase management dialogue - the names affect nothing at all they are just identifiers chosen by the user. 

The question of whether to have a separate demolition phase is a personal choice, the software works with or without that.

On some projects there may be a separate demolition phase in the real world, therefore it would maybe make sense to have that as a separate phase, call it anything you like the name doesn’t matter.

On most of my projects there is no distinct demolition phase on site, demolition and construction occur simultaneously in different areas, so I don’t generally use a separate demolition phase in the model and the Show Previous + Demo filter works fine for me. I have however also used the separate demolition phase method on certain projects where it was merited.

So for me I think you can choose to do it either way, your choice.

[RobDraw]

When I started MEP, we had projects where demolition could be bid out to different contractors than the ones doing construction. We treated every project like this just so we didn't have to switch back and forth. Our demolition drawings had system information. WE DIDN'T USE THE OLD DEMOLITION TOOL. One of my first Revit projects was multiple construction phases with multiple demolition phases. It wasn't easy and was a bit messy but it did go out successfully. 

Apparently, I accomplished something that's not possible? Yay me!

[ToanDN]

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@RobDraw wrote:

When I started MEP, we had projects where demolition could be bid out to different contractors than the ones doing construction. We treated every project like this just so we didn't have to switch back and forth. Our demolition drawings had system information. WE DIDN'T USE THE OLD DEMOLITION TOOL. One of my first Revit projects was multiple construction phases with multiple demolition phases. It wasn't easy and was a bit messy but it did go out successfully. 

Apparently, I accomplished something that's not possible? Yay me!

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Yay you!  How did you demolish, say an existing AHU, in Revit?

[RobDraw]

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@ToanDN wrote:

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Yay you!  How did you demolish, say an existing AHU, in Revit?

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I'm pretty sure I would have assigned it to a demolition phase. I thought that was clear.

How did you do it?

[ToanDN]

Does it's Phase Demolished say None?

Bet you will be dodging to answer for at least 3 posts in.

[RobDraw]

What do you think it would say if I was not using the demolition tool?

These questions seem trivial. 

[ToanDN]

Can't even answer a simple yes or no question? Just as I expected.

[RobDraw]

You seem to be challenging me with questions that you should already know the answers to. 

I usually expect knowledgeable answers from you but when you address me you seem to lose that insight and even make it personal at times. Grow up.

[bmaldonado6X2W5 · Accepted solution]

For MEP at our firm we use the demolition Phase, and the phase filter always remains on "Show All". To me personally it seems to be the easiest way to do Demo and the biggest benefit is that its easy to teach to new Revit users. We have Existing, Demolition, New Construction. If its an existing element it goes in existing, if it will be demo it gets demo'd in Demolition and new goes to new construction. Simple from the MEP perspective. But I understand how other ways make sense too. I guess my biggest frustration is that I can't work in a Demo view to place elements because of the phase filter. I have to create and existing view to place everything that is existing. That issues doesn't happen if we have the demo phase. I place all elements there and once done just grab them all and set them to existing. 

[iainsavage]

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@bmaldonado6X2W5 wrote:

I guess my biggest frustration is that I can't work in a Demo view to place elements because of the phase filter. I have to create and existing view to place everything that is existing. That issues doesn't happen if we have the demo phase. I place all elements there and once done just grab them all and set them to existing. 

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Create views with phase set to Existing (or whatever you want to call it). Create all of the existing elements in these views until you have your "as existing" model built up. Then use that as the starting point for demolishing and creating new objects - just like it would be in the real world.

"I have to create and existing view to place everything that is existing" - yes, that is the correct process. Objects adopt the phase of the view in which they are created. It's far easier to create them in a view of the correct phase rather than having to capture them and change their phase later.

You'll also need those Existing views if you want to include a set of "As Existing" sheets in your construction documents. I don't see why that would be a problem.

"That issues doesn't happen if we have the demo phase. " - with your method it doesn't happen without the demo phase either because you could still place all of your existing objects in the New Construction phase then grab them and change their phase to existing just the same as you are doing in the demo phase.

"I place all elements there and once done just grab them all and set them to existing" - you could do that in any phase/view but its not the best workflow in my opinion.