Vertical Position of the Building

[RossThompson87]

Hi,

I tend to use Google SketchUp for building my geometry. I often find it preferable to use the Architect's datum (generally sea level) as my vertical origin.

This makes checking floor levels etc. very easy.

However when these models are imported into IES, the building may sit say 70m above the ground plane. To be on the safe side I always move it down again.

Is this really necessary? Does the height of a zone above the origin effect wind speed etc?

Ross

[PCully]

I think for completeness and to keep yourself right you should look to position your model treating Z=0 as the ground plane but really it will have no impact on the performance of your project, z-0 is not "ground level", it's just a position in space.

Phil

[JohnLloyd]

I think it'll only have an impact if you've got basement levels.

From memory, Suncast will treat any surface which site below IES's zero plane as being completely shaded. Therefore, unless you manually draw in a large ground floor level your basement walls will receive solar energy.

I suppose it could also impact daylight calcs (and Radiance linked lighting dimming calcs) because reflections from the ground plane will not be correctly calculated??

Probably best to continue moving the building down to Z=0 to be sure.