Exposed Rooftop AC Systems

[unterbau]

Does anyone know what the explanation is for the exposed rooftop AC systems we see on a lot of modern buildings? I continually notice buildings built with those eyesores, and I have no idea why this is. I can respect that in some cases like the ICA, it's a stylistic choice, but is there any reason why it's still so common on other buildings (particularly low & mid rise bldgs)? Do the developers simply not want to pay for the facade to continue above the AC system? Are the architects lazy/dumb/high? Or is there a less sinister reason (energy saving, etc)?

Below I have photo the new LISE building at Harvard, designed by Pritzker Prize winner Rafael Moneo, that, too, suffers this incredibly lame fate.

[czsz]

Afterthoughts? Maybe new/different systems were ordered after the design was complete and too late to modify, or over the course of construction.

I know that these things tend to clutter rooftops more over time as systems get amplified/updated, but it does seem odd that they're present from the beginning.

Interesting example of the Moneo building though - maybe it's just that angle that doesn't cover the ventilation systems? I can see it from my apartment and never really took notice before.

[unterbau]

I suppose having it on top beats the alternative....

[vanshnookenraggen]

Visual clutter, which is something modernists detest, adds character.

[kz1000ps]

I always understood it as being a cost-saving measure... "value engineering," if you will.

[riserise]

In most municipalities, mechanical 'penthouses' do not count towards height limits, whereas if they are located in the body of the building, they push up the highest floors and add to the overall height. Some systems are put in basements, but it's more expensive. Others have to have access to natural ventilation.

[unterbau]

Originally Posted by riserise

In most municipalities, mechanical 'penthouses' do not count towards height limits, whereas if they are located in the body of the building, they push up the highest floors and add to the overall height. Some systems are put in basements, but it's more expensive. Others have to have access to natural ventilation.

So it's essentially a loophole in the building code?

[riserise]

I think it generally has to do with the 'highest occupiable floor'. You can put certain mech. penthouses (usually with their own height restrictions), antennas, etc up there without adding to the defined height of the building. As a side note, this is also why there's debate about how to calculate the height of the tallest skyscrapers. They've shifted the definition from highest occupiable floor, to highest point of structural importance - that's why spires count, but antennas do not.

[unterbau]

Originally Posted by unterbau

Does anyone know what the explanation is for the exposed rooftop AC systems we see on a lot of modern buildings? I continually notice buildings built with those eyesores, and I have no idea why this is. I can respect that in some cases like the ICA, it's a stylistic choice, but is there any reason why it's still so common on other buildings (particularly low & mid rise bldgs)? Do the developers simply not want to pay for the facade to continue above the AC system? Are the architects lazy/dumb/high? Or is there a less sinister reason (energy saving, etc)?

Below I have photo the new LISE building at Harvard, designed by Pritzker Prize winner Rafael Moneo, that, too, suffers this incredibly lame fate.

So apparently I wasn't the only person who disapproved of the AC system on top of the LISE...I just walked by it today and noticed that a visual barrier being put up around it (or at least I assume that's what it is). It doesn't really get to the heart of what I was talking about though...