Transcript Common Building Code Misunderstandings

Common Building Code
Misunderstandings
Increasing Your Awareness of the
Wisconsin Commercial Building Code
By Aaron Halberg, Professional Engineer
Specialists in Post Frame Engineering
| www.halbergengineering.com | P: (866) 694-8602 | F: (866) 391-0916 |
| 10335N DUFFY RD | HAYWARD WI 54843 |
Code Topics to Focus on Today:
• Areas Frequently
Misunderstood
• Awareness of
“Complex” Issues
• Areas with Large Cost
Impacts
• Areas being revised in
the 2011 Code
• A discussion of Snow
Public
Commercial =
or
Place of
Employment
As with any law, there are exceptions so be sure to read the fine print!
Wisconsin Commercial Building Code
Comm. 61-66 : “The Code”
• Adopts the IBC and other
Standards by reference.
• Includes specific amendments
which “trump” the International
Codes and Standards.
• New version this year using 2009
I-Code and new amendments
Some changes coming in 2011
• Live/Work units introduced
• Storm Shelter design standards defined
• Compliance required for Envelope Tightness in
“R” occupancies
• Presumptive Soil Loads must be reduced by ½
for soil bearing values.
• Posting requirement for owners/occupants in
Frost Protected Shallow Foundation buildings.
Some changes coming in 2011
• Truss Design and bracing requirements… new
provisions for trusses spanning over 60’
require a designer to create bracing plans per
latest TPI Standard.
• This requirement is exempted from
Commercial buildings in Wisconsin.
• Should (?) be enforced in buildings that are
not Wisconsin Commercial buildings.
Truss Bracing from BCSI Guide
Occupancy Classification
“Use” of the building
A-1
A-2
Assembly
A-3
I-1
Institutional
A-4
A-5
Business
Education
Factory
B
Mercantile
Residential
Storage
H-3
H-4
H-5
R-2
R-3
R-4
H-1
Hazardous
M
R-1
F-2
H-2
I-3
I-4
E
F-1
I-2
Utility
S-1
S-2
U*
U
Building Volume
• Used for Plan Review Threshold (and for some
municipalities, who can perform the Review)
• Includes all space from Roof Deck to Lowest
Floor and out-to-out on Walls
• Neglect volume under overhangs unless they
are intentionally large enough for storage,
occupancy, or other use of the roof.
Plan Review Thresholds - Current
Occupancy
Classification
Smaller than
25,000 ft3
25,000 ft3 to less
than 50,000 ft3
A-2, A-3
Business
Factory
Mercantile
Storage
Utility
Exempt from
Safety & Buildings
Review
(Still must meet Code &
may still require
local plan review)
May be Registered
in Lieu of S&B
Plan Review
or
Plan Review by
Delegated
Municipalities
A-1, A-4, A-5
Education
High Hazard
Residential
May be Registered
in Lieu of S&B
Plan Review
or
Plan Review by
Delegated
Municipalities
Plan Review by
Safety & Buildings
or
Plan Review by
Delegated
Municipalities
Institutional
Plan Review by
Safety & Buildings or
Plan Review by Delegated Municipalities
50,000 ft3 or
larger
Plan Review by
Safety & Buildings
Plan Review Thresholds - Current
40’ x 64’ x 14’ at 4/12
with 8” heel = 48,600 ft3:
Register or Local Review
(where available)
40’ x 64’ x 16’ at 4/12
with 8” heel = 51,700 ft3:
State Plan Review
required
Plan Review Thresholds – Proposed
Occupancy
Classification
Smaller than
25,000 ft3
25,000 ft3 to less
than 50,000 ft3
A-2, A-3
Business
Factory
Mercantile
Storage
Utility
Exempt from
Safety & Buildings
Review
(Still must meet Code &
may still require
local plan review)
Plan Review by
Safety & Buildings
or
Plan Review by
Delegated
Municipalities
50,000 ft3 or
larger
Plan Review by
Safety & Buildings
A-1, A-4, A-5
Education
High Hazard
Institutional
Residential
Plan Review by
Safety & Buildings
or
Plan Review by
Delegated Municipalities
Plan Review Thresholds - Proposed
40’ x 64’ x 14’ at 4/12
with 8” heel = 48,600 ft3:
State Plan Review
or Local Review (where
available)
40’ x 64’ x 16’ at 4/12
with 8” heel = 51,700 ft3:
State Plan Review
required
Delegated Municipalities
Eau Claire County and Waushara County offer plan
review for buildings less than 50,000 ft3 throughout
those 2 counties.
Additionally, over 200 individual municipalities
(Towns, Villages, or Cities) throughout the state
offer similar services.
As the participating municipalities change over
time, check for the latest information available
through the Safety & Buildings website.
http://commerce.wi.gov/SB/
Occupancy Classification
and Building Size
IBC 503 - Allowable Size
(Base Values, these
may be increased)
Type IIIB
Exterior Noncombustible
Interior any Material
Occupancy
Stories
A-3, Assembly
2
B, Business
Area per Story
Type VB
Exterior and Interior
Using any Material
Stories
Area per Story
9,500
1
6,000
4
19,000
2
9,000
E, Education
2
14,500
1
9,500
F-1, Factory
2
12,000
1
8,500
F-2, Factory
3
18,000
2
13,000
M, Mercantile
4
12,500
1
9,000
S-1, Storage
3
17,500
1
9,000
S-2, Storage
4
26,000
2
13,500
U, Agricultural
2
18,000
2
12,000
Only some occupancies shown. All occupancy classifications and construction types have data shown in the code.
Occupancy Classification
and Building Size
So how big can you make a building? This is where it can
get complex quickly!
• Allowable building area per floor may be increased
with credits for:
– Frontage Access (up to 75% increase)
– Sprinkler Protection (up to 300% increase)
• There are several options available when more than
one occupancy classification exists in the same
building. Separation between occupancies may be
required, but not necessarily.
• Legitimate Mezzanine Areas do not add to the building
area (they do count as part of fire areas).
Occupancy Classification
and Automatic Sprinkler Thresholds
Section 903
Sprinkler Requirements
All Types of Construction have the
Same Sprinkler Threshold Limits
(VB, IIB, IIIB, etc.)
Occupancy
Maximum Fire Area Allowed
without Automatic Sprinklers
A-3, Assembly
12,000
B, Business
none
E, Education
20,000
F-1, Factory
12,000*
F-2, Factory
none
M, Mercantile
12,000
S-1, Storage
12,000
S-2, Storage
none*
U, Agricultural
none
*Woodworking places, Commercial Truck & Bus parking, and others have lower thresholds.
Occupancy Classification
and Automatic Sprinkler Thresholds
To build as large as possible without a fire
sprinkler requirement, both the
Automatic Sprinkler Thresholds
and
Allowable Building Area Limits
must be satisfied.
They are not the same!
Building Height Limit
No modification of limit and not dependent on
Occupancy Classification
Defined as distance from Grade Plane to the average
height of the Highest Roof Surface
Type VB Construction: 40 ft Type IIB and IIIB: 55 ft
Exterior Rated Walls:
Except for High Hazard (H) Occupancies, 10’ of
FSD is enough to avoid Fire Rated Exterior Walls
Allowable Area of Openings in
Exterior Walls: (Doors and Windows)
Table 705.8
Fire Separation
Distance
Unprotected Openings
Allowed
Protected Openings
Allowed
30’ or more
No Limit
No Limit
25’+, but < 30’
70%
No Limit
20’+, but < 25’
45%
No Limit
15’+, but < 20’
25%
75%
10’+, but < 15’
15%
45%
5’+, but < 10’
10%
25%
3’+, but < 5’
Not Permitted
15%
0’ to < 3’
Not Permitted
Not Permitted
Area Increase for Perimeter Access
At least 20’ of space is required to get some credit.
This scenario shows NO increase available to the red
building.
Area Increase for Perimeter Access
With 30’ of space around entire perimeter, the
maximum 75% increase may be obtained.
Building Size and Location Tips
“Tight” site:
Maintain 20’ building between buildings if possible.
Maintain at least 10’ from face of building to
property lines.
Lot line setback on road side is usually not an issue
since IBC measures from building to road centerline.
Always confirm local zoning setback requirements in
addition to State code requirements. Both can have
an impact on project size on “tight” building sites.
Building Size and Location Tips
“Flexible” sites:
Maintain at least 30’ building between buildings and
to lot lines if maximizing allowable area is desirable.
If 30’ space must be violated, minimize the amount
of violation to maximize remaining credit allowed.
Consider future expansion plans in locating the
building, even when beyond owner’s current scope.
For certain occupancies, “Unlimited Area” may be
permitted with 60’ of space around entire building.
Other Complex Code Issues
• Building Additions - why?
– Allowable Area
– Fire Wall / Fire Separation
– Accessibility and Egress Plans
– Structural Issues (Snow Drifts?)
• New Building close to Existing
buildings or to property lines
• Local code requirements
• Wetlands
Structural Issues
Does wind or snow or
gravity affect commercial
and code exempt
buildings differently?
What’s your contingency plan
when you find yourself in a
Code Exempt building during
a “commercial” quality
storm?
What are your building standards
based on?
Would you publish your motto if it is:
“This is how we’ve always done it.”
“Our design includes as much strength as
the owner’s bank can finance.”
“This isn’t how we normally do it, but since
you’ve got another contractor ready to
build it for less, we’ll try it your way.”
Our Current “Pattern” for Ground Snow Loads (ASCE 7 map)
Our Actual Snow Fall
received in the Winter of 07-08:
Design Recommendations
Don’t ignore developments in standards and codes
regarding snow and wind and other design
developments that can benefit Code exempt buildings.
If you’re not able to custom design each building,
consider having your “design system” reviewed by an
engineer you can trust (and afford)
Use the Minimum Design Loads for Buildings (ASCE 7)
as a basis for ALL your building designs. If you decide to
go lower than the normal “safety factor” adjustment for
“Ag” or unoccupied buildings, be prepared with a good
reason for it in case you need it.
This has been
”Common Building Code
Misunderstandings”
Any content of this presentation which you found to be
informative, useful and maybe even entertaining was
intended, although it would be surprising if it happened.
The WFBA was not responsible for the content of this
presentation but they probably wish they were.
By Aaron Halberg, Professional Engineer
Specialists in Post Frame Engineering
| www.halbergengineering.com | P: (866) 694-8602 | F: (866) 391-0916 |
| 10335N DUFFY RD | HAYWARD WI 54843 |