Composite wall skin volume calculation

[Anonymous]

Hi,

I'm trying to find a way to calculate accurately the individual skin volumes of a composite wall for listing. I want to calculate quantities of say, bricks, through individual skin volume.

I'm very new to the calculation features of ArchiCAD, so I might be missing something here. I've found out that you can list the accurate skin volumes, but this skin volume data doesn't seem to be available for further calculation. I also haven't yet found a way to bind a COMPONENT quantity into these skin volumes.

So, now I'm using a property object bound to the wall i want to calculate. I've tried to make up formulas for calculating the volumes myself. I'm up to a point where i have the accurate skin volumes through WALL_SKINS_PARAMS (skin thickness etc.) and WALL_LENGTH_A and B (corrections for angled ends of wall). This method works for at least straight, non slanted, non curved wall.

I cannot however find a way to calculate the subtraction of possible niches and openings from individual skin volumes. Niches should be subtracted from only some skin volumes, and full openings should be subtracted from all skin volumes. So I would need a way to separate the full openings, niches on the A side and niches on the B side.

For now, I have a method for separating full openings and niches, if the niches are on one side only. This can be done by comparing WALL_SURFACE_A and B. This is not perfect however, as it doesn't take in consideration the depth of the niches. While I could live with this problem, the method is unfortunately open to errors because of the limitation to place niches on one side only.

I guess my questions are:

1.Is there a way to pull info from the windows attached to a wall with a property object. I would probably need the ID, name or something to separate niches from full openings, and the side of the possible niches?

2.Can you think of another, simpler and better way to accomplish what I'm trying to do? I have a feeling that I'm trying to do this in a too complex way.

[Rick Thompson]

You really need to achieve this through List Scheme functions, which is very time consuming to set up, but once done it's done. There are many threads on the "calculate" functions, so do a search. Also read the Calculation Guild under AC's help menu.

You'll need to define property objects and attach to your composites. The property object will pull linked data base components that will calculate the quantities.

The Interactive Schedule is worthless for this, as all it generates are volumes. If you could link to property objects then we would have more options, but now as it stands now.

There is also a good book on the subject, but I can't think of the name. It's on many threads though.

[Anonymous]

Thanks for the reply, Rick.
I've gazed through the manual, and I understand the basics of calculation, and List Schemes. I've defined a property object, and I can do calculations based on the TOTAL volume of the wall. I'm just trying to do the same for individual skins of a composite.

I'll try to attach an image. In the image there are three openings; one window and two niches. The window opening volume should be subtracted from all the quantities (face concrete, thermal insulation and core concrete in this example). First niche volume should be subtracted from the two first skin volumes (face concrete and insulation). And the last niche volume should be subtracted only from the last skin volume (core concrete).

The only way I can imagine that this can be done, is to have the individual skin volumes available for calculation, and this is what I'm trying to achieve. If I set the core concrete volume to be proportional to the total volume of the wall, the results will not be accurate. I'm starting to feel that ArchiCAD cannot reach total accuracy with composite structure calculations.

I think this is funny, though, because I can LIST the skin volumes through list scheme setup, and these skin volumes seem to be 100% accurate, including all the niches and probably even SEOs (haven't tried though). I just cannot use that skin volume data for calculating the amount of cement needed (for instance).

[Anonymous]

For anyone interested, I've found a partial solution for this. I can now do accurate volume calculations using a modified niche window object.

The skin volumes can be extracted by a wall property object using the mentioned skin thickness, wall surface length and wall height parameters. All opening volumes will be subtracted from the total volume, and full openings will produce accurate results on their own. Niche volumes will cause errors for skin volume data with the wall property object alone, but these errors are very specific and can be corrected by the niche object's property script. In short; the niche object will add volume for the skins that should not be affected, and subtract volume from the ones the niche actually is hosted in.

It's a bit complicated, but AFAIK it's the only way to get accurate skin volume data for quantity calculation. It's limiting because neither will produce accurate data on their own, but need to be listed together. The quantity calculations will also need to be exactly matching in both property scripts.

For now, I'll settle for this, and will try to develop it a bit further on a project I'm working on. If anyone knows how to get the actual skin volumes of a composite structure available for calculation, I would like to know... This seems like a clumsy workaround.

[Rick Thompson]

I think you this with a property object, but your is is a bit complex. You can reduce for openings. You really don't have to be specific to the skin, but design a database component that has the right "quantity" and "reference quantity" included in that property object. As an example.. see attached property object. It has nothing to do with an individual skin, yet pulls info from the walls length and height.. or volume if I want that info, and quantifies each skin of the wall, as well as what is applied to that wall (paint, DW mud, DW tape etc). I made 2 database components for base. This wall is an exterior wall, so the formula is length x 1. For the database component for baseboard for an interior wall the formula is length x 2 (both sides). It is very flexible and you can do pretty much what you want as long as you know the right multiplier and what proportion to use.

You probably know all this, and more, but I thought it was worth mentioning.

This chanrt will give you that info... http://www.archicadwiki.com/TechNotes/Referenced%20Component%20Quantities

[Anonymous]

Sampaa,

If you have acquired solution at this date kindly communicate here as well as on my mail kanishkaagroup@gmail.com

Regards,

Naraindrra Surryavanshi
Archicad 17.Windows. Int.