Another beginner question: Ground level?

[Nicinus]

I can't seem to figure out how to set the building in relation to the ground level, i.e. how much the stem wall sticks up? It does not seem to be in the structure tab, and I can't find it in the defaults settings, nor in the terrain dbx.

 

 

[buildology]

I think your looking for

Terrain Specification - Building Pad - Pad Elevation

[Electromen]

I think your looking for

Terrain Specification - Building Pad - Pad Elevation

Good answer, I only have one detail to add.  

You would expect Pad Elevation of the Terrain to be referenced to first floor elevation.  The height of all components of the building, such as ceilings, floors, roof planes, etc. are referenced to the height of the first floor, with the floor being zero.  The terrain pad elevation is different, it's measured relative to sea level.

CA automatically finds the center of the first floor and adds 6", (150mm)  plus the thickness of the floor platform and sill plate.  This is the pad elevation of the terrain.

[dshall]

Good answer, I only have one detail to add.  

You would expect Pad Elevation of the Terrain to be referenced to first floor elevation.  The height of all components of the building, such as ceilings, floors, roof planes, etc. are referenced to the height of the first floor, with the floor being zero.  The terrain pad elevation is different, it's measured relative to sea level.

CA automatically finds the center of the first floor and adds 6", (150mm)  plus the thickness of the floor platform and sill plate.  This is the pad elevation of the terrain.

Don't get me started on this. Okay, you got me started. Been asking for this for 4 years.

We should be able to toggle back and forth defining the topo elevations either with respect to the f.f. Or with respect to sea level.

I just did a job where I was doing mental mathematical gymnastics relating retaining wall heights relative to f.f. But having to work off of sea level numbers.

Seriously CA, there should be some simple subroutine you can throw into the program that would allow us the option.

[lbuttery]

do a search on sea level on the old forum

 

plenty of prior discussion and videos about this issue

 

Lew

[glennw]

The pad elevation is very flexible and can be used in 3 ways, but you need to pick a method before you start:

1. All levels relative to sea level (or absolute elevations).

2. All levels relative to zero floor level

3. All levels relative to an assumed datum.

 

I think what d dot is asking for is an automatic conversion between the various methods.

[GerryT]

The system works very well on auto as mentioned above, if you have a SINGLE, square or fairly regular shaped building on a reasonably contoured lot.

 

Everything quickly breaks down if you have multiple buildings or out-buildings, irregular long shapes or bad contours. The reason is basically in how Chief calculates the Terrain height at the center point of the building (which building? – usually the first, but not always).

 

Chief will state that it uses the Terrain elevation at the center point of the building and adjusts from that. But what are they using as the center point of an irregular shaped structure? Is it the centroid, the bounding box center, intersection of dimensions?  Are they indeed using a selected Terrain point or some area average? Even most of Chief’s employees do not know. Just check the archived posts or sent a request into Tech support – you’ll get back nonsense – guarantied. Most likely this area has a bug.

 

So if Chief does not know how this feature actually works – only how it’s supposed to work, any usage is certain to fail as you cannot predict any outcome. Fortunately, on a reasonable contour, offset errors are usually minor.

 

The only solution is the obvious one. Put the building elevation on manual and adjust the pad elevation up/down until you get the effect you need. At least until Chief decides to “Man-Up” on this issue. No squeaky wheel here – just hundreds of complaints and misunderstandings over the years – guess it’s all in the definition of squeaky?

 

In Chief’s defense, using the building elev on manual is not a real burden; the calcs are simple math for any of Glenn’s approaches.  AFAIK, levels within residential buildings are always referenced to ground level, anyway. Construction does generally need a reference to a on-site marker but only for the largest of projects. Only manufacturing uses internal sea-level references – so internal conversions are not needed. An authority may ask for a sea-level elevation at the peak – but come on? There’s more confusion and irritation then a problem here.
 

[lbuttery]

Everything quickly breaks down if you have multiple buildings or out-buildings

 

this is one reason why I put all other buildings in separate plans

then make symbols to be placed in the main plan

 

roofs is another reason for separate plans

 

Lew

[glennw]

 There’s more confusion and irritation then a problem here.

 

 

Gerry,

 

I gotta agree with that.

I can't see the problem with Chief's handling of the building pad.

It allows flexibility.

I know d dot gripes about the lack of auto conversion between the methods, but I find that once you decide which method to use, I never need to convert to another method.

 

The auto pad option is just a down and dirty method of relating the structure to the terrain so that the structure isn't buried underground or floating in the stratosphere.

Does it really matter where on the structure height is calculated - it is an approximation only - if you want more accuracy, don't use auto pad elevation.

It only takes a few seconds to add a manual pad elevation and an elevation height.

 

FYI in Oz, all levels are related to AHD (Australian Height Data) which is mean sea level in 1996.

All my building pads and height information relate to AHD - this allows seamless comparison with situations like adjoining sites, etc.

 

Everything quickly breaks down if you have multiple buildings or out-buildings

 

this is one reason why I put all other buildings in separate plans

then make symbols to be placed in the main plan

 

It would be easier to use manual heights in stead of auto pad height than to use multiple plans and symbols. 

 

roofs is another reason for separate plans

 

I don't get the logic in that one.

[lbuttery]

Glenn:

 

maybe a master of terrain can keep everything straight in a single plan

 

the rest of us mere mortals find it easier to have separate plans

 

same thing with roofs for multiple buildings when using the roof auto-gen

 

if all the roofs are being done manually then it wouldn't matter

 

Lew

[Kbird1]

quote name="Nicinus" post="7357" timestamp="1399778449"]

I can't seem to figure out how to set the building in relation to the ground level, i.e. how much the stem wall sticks up? It does not seem to be in the structure tab, and I can't find it in the defaults settings, nor in the terrain dbx.

note this maybe diff in X6 but without getting into the sea level aspects Nicinus if you leave Auto elevation on for a Stem Wall Foundation Chief adds 6" (old code?... here now 8") plus the thickness of the Floor Structure eg 12 5/8 by default with IJoists so the Terrain will be 18 5/8 below the top of the plywood subfloor.

However you may need to alter that as the 6" takes into account the 1 1/2" treated plate on top of the Stemwall, so the bottom of the Siding will be only 4 1/2 " off finished grade, if like me you need siding to be 8" above grade you need to add 3 3/8 to what ever size is displayed in the Auto Elevation Box. you can check these heights easily with a Backclipped Elevation view thru the wall and use the Tape Measure tool for a quick check....(Note the sill plate doesn't show in this view ,for me anyway, the tape measure will show 1' 1 1/2" to top of floor though not 12" off the stem wall assuming 12" floor structure of 11 1/4 Fir and 3/4 ply).

Siding automatically stops at the bottom of the floor structure whatever it is, which isn't how it is really built but not sure it is worth messing with in Chief to fudge it, but you may need to alter cross section views to be right for planning approval.

The number in the elevation height box is assumed to be negative by chief you don't need a - sign , if you do use one the effect is opposite,it goes up... also the default "ADD" amount is different for different types of Foundations too eg slabs uses +8"

If you are setting contours lines after getting you pad correct above, make sure you are in decimal feet mode ( for N.Amer.), as that is how Surveyors shoot their heights.

M.

aarrrrghhhh.....I hate how this forum now times out when you type a long reply and wont let you post

[Nicinus]

Good feedback, thanks to all. Manual it is then, unless the lot is flat.

 

Kbird1, in my case it does show the automatic as 20 1/8" so it does considers the sill plate, with the mentioned 6". What confused me most was that it didn't seem logical to set the pad elevation in the terrain, I felt that setting belonged to the individual building. As discussed above, it becomes messy with several buildings. Since 'automatic' was checked I assumed there was a default setting somewhere that I couldn't locate.

 

It's funny how it takes a while to understand the 'thought process' of different software packages. One of the concepts I find most different to what I'm used to in Chief must be the way it handles floor levels. I don't mind it and am starting to get used to it, but it seems as if it must be simpler to define the different levels, than having this done on a room by room basis.

[DRAWZILLA]

Siding automatically stops at the bottom of the floor structure whatever it is, which isn't how it is really built but not sure it is worth messing with in Chief to fudge it, but you may need to alter cross section views to be right for planning approval.

 

The is fully adjustable in the wall definitions DBX, It also works for drywall, siding whatever. 

 

 

 

[Kbird1]

Thx P. I would/have never considered that setting to adjust that cos it ain't a brick ledge , this is where CA's terminology throws me sometimes esp. as a Contractor as I use and know the "real terms" for stuff everyday. I see a setting for a brick ledge ...not want I want so ,move on and never looked further into it as I don't remember the last time I did "brick"...

On your image you have interior railings as the wall type so esp. in that case I would of assumed Chief would ignore a brick ledge setting or not even show it ,so thx. again. learning something each time I am here.

M.

[DRAWZILLA]

Thx P. I would/have never considered that setting to adjust that cos it ain't a brick ledge , this is where CA's terminology throws me sometimes esp. as a Contractor as I use and know the "real terms" for stuff everyday. I see a setting for a brick ledge ...not want I want so ,move on and never looked further into it as I don't remember the last time I did "brick"...

On your image you have interior railings as the wall type so esp. in that case I would of assumed Chief would ignore a brick ledge setting or not even show it ,so thx. again. learning something each time I am here.

M.

Yes I wasn't concerned about wall type, just wanted to show where you could adjust this. Thanks