Tutorials for modelling an existing house

[eddymyers]

Hi there, the guys that have replied to me in the past have been so super helpful. As i am trying to teach myself, i was hoping there might be a tutorial somewhere for modelling an existing house. All ther tutorials seem to be for a new build and therefore things seem a bit less....."this needs to be here" and a bit more "you can put that where you like" - do you know what i mean? How can i translate my site sketched to the model.

For instance - at the moment, i an trying to model the existing roof. I am using a generic roof which has 38mm tile, 38mm batten and a 60mm timber base. I have not measured the ground to eaves level becasue at the time of measuring i didnt know i was going to be using this for revit!

I have certain heights of things and i have the pitch of the roof - but i don't know how to get it positioned correctly... Or how to add the purlins/king post truss or ridge beam!

What is the best way to model the existing ceiling joists and ceiling? I have seen the ceiling button, or do i just add a floor?

Thanks in advance

Eddy

[mhiserZFHXS]

Modeling an existing building isn't inherently different than modeling a new building (mostly, other than using phasing if you're doing an addition). So is this an issue of learning how to model elements you haven't modeled before, or a matter of analyzing an existing structure?

[eddymyers]

Thanks for the response, it was mainly to learn how to measure a property to easily then model it. What level of detail to go into - IE do i model each ceiling joist and rafter along with the king post truss? How do i measure to know what level to model the roof at?

[mhiserZFHXS]

There's no correct answer to those things. We don't usually model any of that, whether its new construction or existing. We just model roofs/ceilings/floors with the appropriate tools and add the various material layers, but other firms, especially single family residential firms, might model some or all of those elements. Regarding the roof level, you'll need to measure it and model it at the correct level.

Sometimes you'll just need to estimate some things, especially if there are conditions you can't see or access, and cover your butt with some "verify in field" notes.

[barthbradley]

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@eddymyers wrote:

I have not measured the ground to eaves level becasue at the time of measuring i didnt know i was going to be using this for revit!

What does Revit have to do with it? Even if you are hand drafting the plans, you still need measurements.  And, those  measurements are NOT taken from ground - and nor is eave height even necessary.  Roof pitch/span, plate height and overhang are the only measurements you need to model the roof.  Sounds like you already know its construction, so you know its thickness.  Is it Trusses or Rafters? This information is important as well.   

[eddymyers]

it is a roof with a king post truss, purlins and rafters.

How do you measure the plate height of a house?

I have realised that there is a king post truss family in the folder so i loaded that but then had trouble trying to make it look like the one in the house! I am sure it is all easy....once you get used to it! hahahaha

[barthbradley]

Honestly, you are getting way, way too deep into the weeds if you are modeling individual trusses, purlins and rafters. What's the point?        

[eddymyers]

I don't know - to be honest! I am new to this and in CAD i would be drawing all of these things. Do you just model the overall roof depth and leave it at that?

I have realised that the plate height is effectively 20mm above first floor ceiling height. It is still difficult to get my head around the way of modelling and therefore the bits of information needed on a site survey

[ToanDN]

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@eddymyers wrote:
Thanks for the response, it was mainly to learn how to measure a property to easily then model it. What level of detail to go into - IE do i model each ceiling joist and rafter along with the king post truss? How do i measure to know what level to model the roof at?

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Keep it simple.  

You don't need to invest time in modelling stuff that will be demolished with great details.  Further down the road, you can add modelling details to the existing portion that matters so that they can interface with the new construction properly.

[Caed9]

Remember Revit Stands for "Revise isntantly". And sometimes it frustrating when you want to have everything in the model to be placed  as it is supposed to be right away, I say it cause I've been there and I'm still learning. So, my advice will be: create the model with the measurements you know you have, Place all of the family elements you think might be crucial to have, like placing generic Beams, Joists, Columns Etc. 

Create the model, and make it similar as your house, with the same amount of elements(Columns. Joist, Beams, Purlins, Etc.). Once you have all of the elements assembled in a similar way as your house. Check one by one, " Revise", and check which real measurements you are missing and then Edit the model to match the real world dimensions. But first create the rough Model then polish it by revising what you need to change.