exterior wall area facing in one direction on any side of a building

[sunyaer]

This is from Ontario building code:
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9.10.14.2. Area and Location of Exposing Building Face
(1) The area of an exposing building face shall be,
(a) taken as the exterior wall area facing in one direction on any side of a building, and
(b) calculated as,
(i) the total area measured from the finished ground level to the uppermost ceiling, or
(ii) the area for each fire compartment, where a building is divided into fire compartments by fire separations
with fire-resistance ratings not less than 45 min.
(2) For the purpose of using Table 9.10.14.4. to determine the maximum aggregate
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Are there scenarios where an exterior wall area faces in more than one directions on any side of a building?

 

[Msradell]

A circular building perhaps?

 

[Jay Smith]

On this building there is an aggregate area of wall facing the street on the right. There is also an aggregate area of wall facing the street on the left.

https://st2.depositphotos.com/1134101/11202/i/950/depositphotos_112028558-stock-photo-the-bank-of-america-plaza.jpg

 

[Genduct]

The lot line is not a straight line and changes direction?
I like the circular answer as a possibility

 

[Mark K]

The default assumption in the US is that the wind can come from any direction. The projected area of the wind from a given wind direction is multiplied by the calculated wind pressures for that wind direction to determine wind forces.

In many buildings it is only necessary to consider two perpendicular directions. but the engineer needs to understand the implications of the directions chosen.

There is a difference between the wind on the cladding and the wind forces on the global wind force resisting system.

For a circular building if the wind force resisting system is orthogonal while the total forces may be the same you still need to consider each direction when designing the wind force resisting system.

This should not be a mystery for licensed civil engineers.

 

[sunyaer]

The default assumption in the US is that the wind can come from any direction. The projected area of the wind from a given wind direction is multiplied by the calculated wind pressures for that wind direction to determine wind forces.

In many buildings it is only necessary to consider two perpendicular directions. but the engineer needs to understand the implications of the directions chosen.

There is a difference between the wind on the cladding and the wind forces on the global wind force resisting system.

For a circular building if the wind force resisting system is orthogonal while the total forces may be the same you still need to consider each direction when designing the wind force resisting system.

This should not be a mystery for licensed civil engineers.

It looks like Ontario building code part 3 stipulates more on fire regulation than structural requirements.

 

[Inspector Gadget]

It looks like Ontario building code part 3 stipulates more on fire regulation than structural requirements.

The structural is going to be subsumed under Part 4. That's for the iron-ring folks.... not us.

The intent of the spatial separation code is to prevent the spread of fire from one building/compartment to adjacent properties/adjacent buildings.
For example I have one building where there is a "jog" on a front section, facing a street. The plane of the building facing the street has no restrictions; the plane of the "jog" is parallel to a property line and is considered part of the corner wall for the purposes of calculating assembly components.
3.2.3.1

"3) For the purpose of determining the type of construction and cladding and the fire-resistance rating of an exterior wall,
a) the exposing building face shall be taken as the projection of the exterior wall onto a vertical plane located so that no portion of the exterior wall of the building or of a fire compartment, if the fire compartment complies with the requirements of Article 3.2.3.2., is between the vertical plane and the line to
which the limiting distance is measured, and..."
Similar language in Part 9.
From what I have seen, it's this requirement that throws people.

In the cases of odd-shaped buildings, or, say buildings facing another at an odd angle, there are general processes to guide a designer/inspector to a reasonable outcome. The NBC illustrated guides have some useful diagrams on how to navigate such situations.

 

[tmurray]

This is from Ontario building code:
----------------------------------------------------------------------------------------------------------------------
9.10.14.2. Area and Location of Exposing Building Face
(1) The area of an exposing building face shall be,
(a) taken as the exterior wall area facing in one direction on any side of a building, and
(b) calculated as,
(i) the total area measured from the finished ground level to the uppermost ceiling, or
(ii) the area for each fire compartment, where a building is divided into fire compartments by fire separations
with fire-resistance ratings not less than 45 min.
(2) For the purpose of using Table 9.10.14.4. to determine the maximum aggregate
-----------------------------------------------------------------------------------------------------------------------

Are there scenarios where an exterior wall area faces in more than one directions on any side of a building?

No. If you have a situation where the difference between the building face and the property line vary, you take it from the most restrictive case.

 

[tmurray]

The default assumption in the US is that the wind can come from any direction. The projected area of the wind from a given wind direction is multiplied by the calculated wind pressures for that wind direction to determine wind forces.

In many buildings it is only necessary to consider two perpendicular directions. but the engineer needs to understand the implications of the directions chosen.

There is a difference between the wind on the cladding and the wind forces on the global wind force resisting system.

For a circular building if the wind force resisting system is orthogonal while the total forces may be the same you still need to consider each direction when designing the wind force resisting system.

This should not be a mystery for licensed civil engineers.

9.10 deals specifically with fire provisions. The intent of this section is to limit the spread of fire between buildings by requiring more restrictive construction requirements as a building gets closer to a property line, or a line between two buildings on the same lot.