MaltbyDesign Posted December 20, 2020 Share Posted December 20, 2020 Hi folks, I'm preparing a model of an existing house which will have an addition added to and it has a saltbox style roof (asymmetric gable). I've attached some images of a building section, roof plan and elevation for reference. The second floor steps back and is about half the width of the main floor, resulting in a roof that spans from the top of the wall at the second floor to the top of the wall at the first floor, forming a double height volume resulting in the asymmetric gable. What is the best way to model this roof that allows me to add the gables and skylights easily? I don't need a lot of detail in the roof object, as the existing house will be treated as a simple white object in 3-D. Quote Link to comment
Jeff Prince Posted December 21, 2020 Share Posted December 21, 2020 I'm not sure of the best way, but this can be achieved using Clip Object to shape the roof. Trace the roof plan, roof lines and footprint. Basically construct the main roof with the differing bearing heights first as an imaginary roof that extends beyond the cut plane such that your ridge lands in the correct place. Set your gables on this roof. Next, use rectangles to clip the roof on the east side to the desired eave location. You now have a roof as depicted in your section. Use the same technique to cut out where the other intersecting roofs will exist on this main roof. It should be looking nice and complicated now. Then add those smaller roofs one at a time, stick then on a separate design layer from your main roof for the next step. Use your building footprint to generate walls. Select all the walls that should extend to the main roof and use "fit walls to object", selecting the main roof's design layer Repeat this process for the walls that should extend to the secondary roofs, making minor adjustments to the walls as necessary. The attached file kind of graphically breaks it down into steps to compliment the cutting description above. I tried to use classes and design layers that are self explanatory, but I may have mixed a few thing up in my haste. I also noticed that I missed trimming a piece of roof in this example. Anyhow, hope it helps. Should be pretty easy for you using this technique. The longest part of the job was tracing the roof plan 😉 saltbox roof.vwx 2 Quote Link to comment
CipesDesign Posted December 21, 2020 Share Posted December 21, 2020 Old School: Start with Create Roof(s) then Ungroup which will produce various Roof Faces. These can be easily Clipped/Added... 3 Quote Link to comment
Jeff Prince Posted December 21, 2020 Share Posted December 21, 2020 @CipesDesign why would ungroup them for this example? Simple roofs are easy enough to clip with the object intact, curious if I'm missing something. Quote Link to comment
MaltbyDesign Posted December 22, 2020 Author Share Posted December 22, 2020 Thanks very much for the info. @jeff prince I'm not sure I follow your process. I'm going to have to spend some time studying your drawing to see if I can't figure it out. I appreciate the time you spent on this. 1 Quote Link to comment
Jeff Prince Posted December 22, 2020 Share Posted December 22, 2020 @MaltbyDesign No problem, not my finest moment in explaining 🙂 Here's an updated file with a little more information and steps, including the evolution of the roof forms with each editing operation. It's pretty fast when approached systematically, especially if you are starting with 2D drawings. Maybe one of the talented architects here on the forum will spill the beans on how they do roofs. saltbox roof2.vwx 1 Quote Link to comment
bcd Posted December 22, 2020 Share Posted December 22, 2020 An easy way - because the bearing heights and rafter lengths are different front and back is to use roof faces: Plan View - draw a rectangles representing the front roof AEC>Roof Face Axis 0 Set the correct slope Two clicks to draw the the 'bearing line' along the ridge line and a third click to denote the up-slope repeat for the back roof Move the roofs a hair apart and connect them at the ridge using the Connect/Combine tool. Lift the roofs to the correct elevation 1 Quote Link to comment
Kevin K Posted December 22, 2020 Share Posted December 22, 2020 Yeah, I second the approach using individual roof faces. These roofs are not a good candidate for using the roof tool. No real mystery in creating them really. Just one step at a time. Really good you have the existing drawings of the house. That helps. 1 Quote Link to comment
Kevin K Posted December 22, 2020 Share Posted December 22, 2020 That said, it is unfortunate that the person who drew these fairly ancient plans didn’t bother to note the roof pitches on the roof plan sheet. That makes things a bit more difficult in that you have to refer to the sections for that info....which in looking at your image of the section, those pitches are not even noted there, from what I see. Quote Link to comment
taoist Posted December 22, 2020 Share Posted December 22, 2020 Another reason for Roof Tool upgrade. We should be able to have a Multi Story Roof Option. Also, more choices in roof styles, even profiles. FWIW 2 Quote Link to comment
Tom W. Posted December 22, 2020 Share Posted December 22, 2020 I would be great to be able to create a roof based on bearing height + ridge height as well as bearing height + roof pitch, for circumstances such as this where you have the former information but not the latter. This was a Wishlist item I made about the Massing Model tool where I have site surveys with eaves heights + ridge heights of buildings but in order to create massing models of them I have to separately work out what the roof angle equates to for each one. 2 Quote Link to comment
MaltbyDesign Posted December 22, 2020 Author Share Posted December 22, 2020 Thanks again for the tips, all. I think I've got the roof figured out but got bogged down again with Storeys and trying to model an existing home and figuring out existing and new construction. Back to 2D drawing in AutoCAD for this project. I think I'll reserve 3D for new builds only, for the time being. Quote Link to comment
taoist Posted December 22, 2020 Share Posted December 22, 2020 9 minutes ago, MaltbyDesign said: Thanks again for the tips, all. I think I've got the roof figured out but got bogged down again with Storeys and trying to model an existing home and figuring out existing and new construction. Back to 2D drawing in AutoCAD for this project. I think I'll reserve 3D for new builds only, for the time being. Just curious. Why AutoCad for 2d? Why not Vectorworks Quote Link to comment
MaltbyDesign Posted December 22, 2020 Author Share Posted December 22, 2020 @taoist Because I know it backwards and inside out. I've been using it since release 10. It's required software for most of my work. I've been using VW for a few jobs here and there but haven't reached the skill level where it's not a struggle. I'm hoping to move to it completely, eventually but this project won't be it. Quote Link to comment
CipesDesign Posted December 22, 2020 Share Posted December 22, 2020 A note regarding Stories... I never use them! IMO they only made the whole user experience more confusing. That said, I *think* (someone could correct me or verify) that Stories were added to facilitate BIM/ICF capabilities. As a small one-person operation specializing in one-off residential design I don't need those capabilities. Also, IMO all the "automated" drawing/file setup tools are dangerous as they prevent the user from learning the basics of Layers and Classes and how to set up a file manually, which is really easy in most cases. Again speaking from my experience and needs. Large projects with multiple users are a different story (pun??). Quote Link to comment
taoist Posted December 22, 2020 Share Posted December 22, 2020 I do not find it Automated. One still needs to Manually enter Layers, Classes, Levels. Then, one is able to use what they have setup. I still have drawings when I used layers, classes only. Still had to manually enter all those. This is all part of good Design. I recall from years ago when were going to frame a house we would layout a Story Pole of the house. Floor Joists (1st Story) Shoe Plate Cripple Studs Window Sill plate(s) Headers Top Plates Floor Joist (2nd Story) Cripple Studs Shoe Plate Window Sill plate(s) Headers Top Plates Etc... Quote Link to comment
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