# Snow drifting



## Pais (May 27, 2014)

Second story addition on existing building at zero setback to property line.  The addition effects the next door neighbors building with respect to drifting of snow.  Who is responsible to ensure the neighbors existing building is not effected by the additional snow drifting caused by the addition next door?  Should the property owner that is constructing the addition pay for a structural design and possible repair of the adjoining building?  2012 IEBC section 1103.4 Any structural element of an existing building subjected to addition loads from the effects of snow drift as a result of an addition shall comply with the International Building Code.  Does this mean if the addition effects the adjoining building then the adjoining building has to meet additional snow drifting requirements? Who pays for this?


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## steveray (May 27, 2014)

Yes.....person authorizing the work (property owner) is responsible...


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## Darren Emery (May 28, 2014)

Interesting concept.  Haven't read enough to speak to the accuracy of Steve's answer.  But... how do you enforce code required improvements upon another property?

Let's say the addition on property A does create a problem for a building on property B.  And, to make it interesting, lets say owner A is willing and able to pay for structural modifications to building on property B.  What happens when Owner B says "no thanks, I like my home exactly the way it is".

What then?


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## steveray (May 28, 2014)

At least quickly...This...

SECTION 3307 PROTECTION OF ADJOINING PROPERTY

3307.1 Protection required.

Adjoining public and private property shall be protected from damage during construction, remodeling and demolition work. Protection shall be provided for footings, foundations, party walls, chimneys, skylights and roofs. Provisions shall be made to control water runoff and erosion during construction or demolition activities. The person making or causing an excavation to be made shall provide written notice to the owners of adjoining buildings advising them that the excavation is to be made and that the adjoining buildings should be protected. Said notification shall be delivered not less than 10 days prior to the scheduled starting date of the excavation.


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## steveray (May 28, 2014)

I agree it is a great question.....Hopefully I wouldn't have approved the permit for building A yet....It is a defacto alteration to building B by changing the loading...It would at least need to be analyzed to see if would work. Same thing we do here when we reroof a flat roof, insulation needs to be upgraded, then it has to be determined if a reduction in roof loading was taken for lack of insulation, and wether or not the structure still works....A little different because it is one owner, but you can't let one building negatively affect a safety feature of another building...

I think the OP with the 1103.4 has all of the code section that would be required...


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## Msradell (May 28, 2014)

Very interesting question but that I know of there isn't any software available to model snow drifting especially that caused by wind currents around buildings.  It's just anyone's guess if the building addition will even change snow drifting.  From my interpretation 3307.1 only deals with the protection of adjoining property during the construction process.  It doesn't reference how what is being constructed affects the adjoining property after it is completed.


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## Phil (May 28, 2014)

Msradell,

Code requirements for drifting snow loads are in ASCE 7. The drift loads on low roofs can be brutal. Pais poses a good question, I wonder how this it typically handled.


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## Mark K (May 28, 2014)

This is a situation where what may make sense technically is at odds with the legal requirements.

While the new building, on a separate property, may impact the snow loading on an existing adjacent property there is no requirement that the existing property be upgraded nor is there a requirement that the cost of any upgrade be paid for by the owner of the new building.  If both buildings were on the same property then the owner of the property would be required to consider this issue.  The code is applied to each property ignoring what is on the adjacent property.

Any building official who attempts to impose a requirement that the new building be reinforced for the new snow loads should have a  good lawyer and the support of his local jurisdiction.

When there is a building built right up to the property line we do not require that the subsequent new building be designed to accommodate the  drift from the original building.

Another case would be if the wind loads were calculated assuming that the adjacent properties were covered with trees and these trees were subsequently cut down.

Do you  want to require that all buildings built under a previous code have their lateral system strengthened when the current code would require significantly higher design forces or would prohibit the lateral system that was used?


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## tmurray (May 28, 2014)

Mark K said:
			
		

> The code is applied to each property ignoring what is on the adjacent property.


I think this statement says it all. You might want to inform the applicant of the potential negative impact their building could have on the adjacent property owner so they can mitigate liability, but there is nothing required.


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## JBI (May 28, 2014)

For the case at hand, I too agree that the Code does not apply to the adjoining property as opined.

However I do not agree completely with Mark K's posit... Fire Separation Distance is clearly a place where the Code is applied to each property with full regard for adjoining properties.

That said, the misapplication of a provision designed to insure that an addition does not compromise the integrity of the building being added on to should ne be encouraged. The section quoted has nothing to do with buildings other than the building being added on to.


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## steveray (May 28, 2014)

I am not going to argue this one too vigorously, but I agree with JBI to some extent. Code clearly has examples of crossing property lines. Example:  Similar situation to OP, zero property line, firewall, any expansion has to be considered for both buildings. Open perimeter, fire seperation,loading all may be issues and others.....

How about this code section....SECTION 114 VIOLATIONS

[A] 114.1 Unlawful acts.

It shall be unlawful for any person, firm or corporation to erect, construct, alter, extend, repair, move, remove, demolish or occupy any building, structure or equipment regulated by this code, or cause same to be done, in conflict with or in violation of any of the provisions of this code.

You are altering the drift loading on the roof...causing the building to not meet code...good enough for me.....


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## fireguy (May 28, 2014)

Next subject.  My neighbor adds another story to his house.  His actions cause my house and property to be the shadow of his new addition.  His action causes a change in my enjoyment of the rays of the sun.  Does he have to build me a new deck?   Or now the snow in my drive does not melt off as quickly.  Does he have to pay someone to remove the snow from my driveway? The plow driver is not properly insured and damages my house.  Where does it stop?


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## Frank (May 28, 2014)

Such is the subject of many fights to limit rezoning or planning approvals for work on neighboring property.


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## Mark K (May 28, 2014)

There has been considerable litigation over blocking of views and while there may be liability it is not a building code issue.  More recently I have heard about zoning regulations, not building code, that would prevent new construction from blocking the solar panels on an existing building on adjacent property.

Issues such as fire walls or zero property lines are applied without consideration of what is actually built on the adjacent property.

If the zoning regulations effectively prevented you from building on a property based on what was already constructed on adjacent properties this might be considered a "regulatory taking" thus requiring you to be paid by the City for the loss of economic value to the property.  As I said before if you want to regulate based on what was actually built on adjacent property, get a good attorney.


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## steveray (May 28, 2014)

FG....Building safety is what we are talking about and dealing with...SFD egress and authority for us ends at the steps or ramp to grade. Unless the IPMC covers icy driveways...N/A....If it were a commercial property and egress, there might be something under keeping them free of snow and ice that one could or should enforce.... It's there for stairs and ramps, but not all walking surfaces I believe...


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## ICE (May 28, 2014)

fireguy said:
			
		

> Next subject.  My neighbor adds another story to his house.  His actions cause my house and property to be the shadow of his new addition.  His action causes a change in my enjoyment of the rays of the sun.


Can we add a PV system to the scenario?


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## ICE (May 28, 2014)

The Disney Concert Hall in Los Angeles has a shiny metal skin. Parabolic portions focused sunlight on an adjacent building and raised the indoor temperature to unbearable levels. That had to be remedied.  Google it for more on the story.


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## steveray (May 28, 2014)

Frikin' laser beams..... 



			
				ICE said:
			
		

> The Disney Concert Hall in Los Angeles has a shiny metal skin. Parabolic portions focused sunlight on an adjacent building and raised the indoor temperature to unbearable levels. That had to be remedied.  Google it for more on the story.


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## Wayne (May 29, 2014)

Re: Snow drifting



			
				ICE said:
			
		

> The Disney Concert Hall in Los Angeles has a shiny metal skin. Parabolic portions focused sunlight on an adjacent building and raised the indoor temperature to unbearable levels. That had to be remedied.  Google it for more on the story.


Reminds me of the Vdara Death Ray here in Las Vegas, which has since been "fixed".

http://www.reviewjournal.com/news/vdara-visitor-death-ray-scorched-hair


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## Mark K (May 29, 2014)

The Disney Concert Hall problem was not a building code violation and thus not a matter for concern by the building department.

The important thing to remember is that not all problems related to buildings can be solved by the building code or by code enforcement.


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## ICE (May 29, 2014)

Mark K said:
			
		

> The Disney Concert Hall problem was not a building code violation and thus not a matter for concern by the building department.


Kinda like snowflakes huh.


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## Msradell (May 29, 2014)

Phil said:
			
		

> Msradell,Code requirements for drifting snow loads are in ASCE 7. The drift loads on low roofs can be brutal. Pais poses a good question, I wonder how this it typically handled.


I know that ASCE 7 addresses snowdrift loading.  However when I stated was there is no way to model how the drifting on a given building will be affected by a 2nd building.  All of the modeling in ASCE 7 that I've read refers to the effects of drifting on a building they features of that building such as the Windward in leeward sides of a hip roof or gable roof.  I've never seen any description of how to model how one building can affect the snow loading on a 2nd non-connected to building.


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## Phil (May 29, 2014)

Msradell,

I thought the discussion was about buildings with zero set back. If that is the case and the building right next to each other with negligible separation, the snow doesn't care about the building separations or the lot lines.


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## JBI (May 29, 2014)

"It's a civil matter, between the parties, and not anything this office can address directly."

Can't tell you how many times I had to say that in 17 years of direct enforcement. itty


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