Terrain contour "dips" near garage stem wall


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Hello. I've been working on the terrain elevations on my home plan and am running into a bit of strange behavior around my garage. I would like for the finished ground (concrete) around the garage structure to slope up slightly (about 2-4" vs surrounding ground) within the 8-12" area closest to the wall so as to divert water flow away from the foundation and away from the door openings. But for some reason, the concrete terrain keeps "dipping" down a few inches as it nears the stem wall. In the below perspective screenshot, the read outlined area is what I don't want. The green outlined area is what I do want.





The below screenshot shows approximate intended storm water drainage flow in rough ugly blue arrows (mspaint - sorry) along with the approximate camera angle for the shot taken above. I've tried placing elevation lines, elevation regions, and raised regions a few inches higher than the surrounding ground along the wall in an attempt to force the terrain to slope up towards the wall, to no avail.




Can somebody please help me figure out why my terrain keeps "dipping" as it nears the garage walls? 


Thank you!


Home Designer Pro 2020



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Hi David. Long time. Hope you've been well. That's strange. I've found that the contours of the concrete terrain aren't super visible without messing around with the sunlight angles for the 3D perspective camera. Do you know if there's a better way to illustrate the contours in 3D perspective views? It would be nice to be able to impose a grid (like graph paper) over the terrain.


I managed to correct most of the contours of the overall yard around the garage (see below)...




But if I pull the terrain to cover the last few inches near the garage wall (under the swinging door entry), I get "the dip" again (see below)...




I attached an updated ZIP/Grading plan. If you can't open it, no worries. I think the plan is "good enough"  now. I'd love it if you could help me figure this out - It's just really bothering me. :)






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Hi David.

  1. You're hilarious while incredibly helpful. Your Texas humor made for a good morning laugh. Thank you!
  2. I should have clarified my goal. 
    1. My goal with this grading plan is to communicate to my City Building/Engineering dept how I plan to drain storm water as we re-pave the driveway and back yard.
    2. While I wish I had a flat property that drained storm water gracefully to the street (I'm supposed to avoid draining to my neighbors' properties)...
      1. My property forms a slight but very large "pit" in the back yard where the low point is about 21 inches lower than the high point next to my porch. This causes storm water to collect and flood in that area.
      2. At the rear (left/west) is a retaining wall with the neighbor's terrain about 18" higher than mine.
      3. Towards the front (right/east) of my property is a high spot where you see the flat rectangular elevation area next to the porch.
    3. The city wants to know how I plan to drain storm water, so my dad (structural engineer) proposes a sump pit which I chose to place next to the garage, away from the huge Oak tree that sits near the current low point in our property.
    4. Currently, since storm water drains near the oak tree, this seems to be encouraging it to grow its roots into our driveway, creating some ugly breaks and undulations in the existing pavement.
  3. The elevation points and colorful CAD lines (existing structures) were imported from a topographical survey I had done (see attached, Topo...plan). I used these as reference/starting points, but...
    1. I've found that the survey points don't make for a very good terrain/grading plan in Home Designer Pro.
    2. I removed many of the survey points in the rear as I planned for the new grade.
    3. But since I'm not touching the front (this project is an extension of the house towards the rear and a replacement of the garage), I made the best of it by leaving most of the points as-is.
  4. With respect to the elevation data In the plan...
    1. Where you see -24" overlapping the of +22" 
      1. The +22" is an Elevation Line (as expected) but...
      2. The -24" is a "Raised/Lowered region" which I pulled from Terrain -> Modifiers. i.e. I don't think it's an elevation region. I'm still learning to use these modifiers, but I had the impression that these are specified in relative heights, rather than absolute heights (as Elevation Lines would be).
      3. Also, I found that a narrow "Lowered Region" modifier doesn't actually modify the full specified height modification of -24... I had to set this extreme value to get the effect that I wanted, which is to mildly "dip" the pavement to route water behind (left of) the garage and towards the sump pit. 
  5. The terrain "dips" that I'm trying to address are very subtle and only show in the few inches immediately adjacent to the garage wall. 
    In your video, I do see the dips in your 3D Perspective view,
    1. ... at 15:31 ...
    2. ... at 15:39...
    3. ... you'd have to zoom way into the wall (like you're crawling on the ground carefully eyeballing where the wall meets the ground).


I appreciate your coaching and expertise. If the city notices that the elevation contours take a dip near the garage walls, I'm resolved to simply explaining verbally to them that this is not the intended design, but a software issue that I can't seem to overcome.


Thanks again David for your generosity, expertise, and humor!




Edited by jplee123
Adding screenshots of David's video
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Here's my guess ... I've been having the same nit-noid problems for 3 years and 3 versions of Home Designer Pro ... which apparently isn't any where near as functional as Premier X12 which the program people who have been trying to help you are using to view your plans. 


I'm doing a full walk-out basement house and for the first two years I just figured I sucked at using this tool and had the dipping at the foundation error, failed to importing the actual terrain files, can't get the roof over to where I need it, and on and on ... then I watch the videos that make all of this look so easy and realized ... these helpful souls and the company aren't using the 1+done tool us owner builders thought we purchased (I use HD Architectural 2021) but they are using the professional version X12.  We simply have a teaser tool which I was okay with me as my engineers will clean up and redraw all of it with their tools.  Sure would have been nice if the company made clear "this tool is for visualization only" at the onset so I wouldn't have wasted so much time. As far as I know there is zero engineering calculations for load bearing etc in this software. 


I seriously doubt I'll ever be able to generate stamp-able plans that get approved by my simple county with this software and I'm not sure I would pay another $2k to upgrade only to find out that Premier X12 won't be acceptable either.   Would be curious to know if any architects use Premier X12 and if they have produced plans that have been approved and built?

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11 minutes ago, Jo_Ann said:

Instead of trying to fashion a complicated elevation detain around the garage, maybe you should consider using french drains?

Thanks Jo_Ann. Where would you put the french drains? Would you use more than one in the location of the sump pit I've got on my plan? See bottom of the below screenshot.image.png.618cb8bfd2ebff8f13cb3743a750df54.png


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@ResQav8r - I love your use of the term nit-noid. That is exactly what this problem is for me. The terrain "dip" near the walls is probably inconsequential. And I tend to waste time trying to answer all the possible questions the viewer(s) (city engineers) might ask. I need to move on to the other layouts (floor, elevations, etc). 


Having said that, my father (structural engineer) does work with a development firm that has no architects - only draftsmen. He signs off on their A-sheet (Architectural) plans. All the structural detail and calculations he does in AutoCAD.


We're taking a similar approach on this project (my home extension + new garage) with me using my amateur HD Pro 2020 skills to create A-sheets and my dad (SE) creating structural details in AutoCAD and calcs on good old fashions paper. He will stamp and sign my A-sheets. If the city starts asking for more architectural detail, I may rent Chief Premier for a month or two ($199/mo) to get them what they want. Visualizations is all I need for the A-sheets, but I do wish I had Layout Sets, the ability to create multiple layouts from one plan and symbol Legends. With HD Pro, I'm having to copy and modify a plan file per layout since I can only show 1 set of layers within a given .plan file.


I did start my work with a professional architect who uses Chief Architect, but I got burned and ended up parting ways him - unfortunately after I had already made 80% of the scheduled payments. The .plan files posted here are entirely mine. This architect made copies and modified them, but added very little value in terms of design and planning with the City. He never even visited my site nor did he communicate with the City effectively.


Like you, I'm envious of the Professionals here that use Chief Architect rather than Home Designer. But I can't justify spending thousands more in software for my one project. It has been fun to learn this software though, especially with folks like @DavidJPotter helping me with the difficult stuff! Thanks David! 



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5 hours ago, ResQav8r said:

Would be curious to know if any architects use Premier X12 and if they have produced plans that have been approved and built?


Architects and Engineers use Chief but when it comes to drainage systems, which only perhaps Landscape Architects and Engineers would legally do. Most of them use text and arrows as has been done by you and others. Chief is not used by Surveyors, they have their own dedicated software for that and their software is really expensive compared to Premier.


My advice is to model the terrain as close as is possible but then in plan view show your intentions to the city with text and arrows showing highs, lows and flow channels as you have done here in this forum. In other words, keep it simple.



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On 7/13/2020 at 3:29 AM, ResQav8r said:

Would be curious to know if any architects use Premier X12 and if they have produced plans that have been approved and built?

An Interesting forum post I must say - thanks.

Hi - I have used HDPro (since 2015) for various Local Planning/Council Approval drawings/applications - no worries at all;

Can't seem to get the ultimate resolve about moving to CA - anywhere or from anyone. Lots of opinions.

It depends on drafting capabilities and personal experience in this field I add.

HDPro is a most adequate and useable application for my select works.

When I need to prepare site management or drainage management schematics (like you have) I would use a more focused software.


PS - What is a 'french drain'? ( I'm not french btw.) Pardon.

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