BOMA Floor Measurement Best Practices

What BOMA standard should be used for measuring the floor area of an office building that belongs entirely to one single occupant?
(Applicable to ANSI/BOMA Z65.1-2010)

The BOMA Office Standard has always stated that the area of a Major Vertical Penetration includes the thickness of its enclosing walls. Is that true even when a Major Vertical Penetration is next to an exterior building wall? How about other classes of space listed in the Wall Priority Diagram (Chart #2) of the BOMA 2010 Office Standard? (Applicable to ANSI/BOMA Z65.1-2010)

The Interior Gross Area (IGA) of a building is determined using “Chart 1 - IGA Boundary Conditions” in Section 4 of the BOMA 2010 Office Standard without regard to interior area class.  Because no areas may be measured outside the IGA Boundary, the area of a Major Vertical Penetration would not include the thickness of the exterior enclosure of a building.

There are three exceptions:

1. Any class of space that is adjacent to a Public Pedestrian Thoroughfare extends to the Enclosure Limit, which is the IGA Boundary for that condition (See IGA Condition #2, Chart #1).

2. Any class of space that is adjacent to a Property Line between two different owners extends to that Property Line. (See IGA Condition #9, Chart #1).

3. Major Vertical Penetrations and Building Service Areas that are adjacent to External Circulation generally include the thickness of exterior enclosing walls because External Circulation is inside the IGA Boundary and is generally classified as Floor Service Area or Base Building Circulation in Method B, which has lower wall priority than Floor Service Area on Chart #2.

Support: Section 3: Overview of Measurement Methods.

Examples:

Illustration 10.6 page #49 of ANSI/BOMA Z65.1-2010

Illustration 11.6 page #55 of ANSI/BOMA Z65.1-2010

Illustration 12.4 page #59 of ANSI/BOMA Z65.1-2010

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

Purpose: to provide a consistent, detailed method of allocating inter-building service and amenity areas among different buildings that they serve in a multi-building set in accordance with general direction included in the BOMA 2010 Office Standard.
(Applicable to ANSI/BOMA Z65.1-2010)

Are common areas apportioned to the Gross Leasable Area of retail tenants? (Also applicable to ANSI/BOMA Z65.1-2010)

The short answer is “no”.

Gross Leasable Area (GLA) is a space classification used to measure floor area in retail buildings and is defined in the BOMA Retail Standard (ANSI/BOMA Z65.5-2012). Under the BOMA Retail Standard common areas are not factored into a tenant’s Gross Leasable Area because it is normal for operating expenses for common areas to be apportioned between tenants based upon their GLA. This is different than the case in office buildings.

BOMA “store area” was defined in the previous BOMA Standard published in 1996 and intended for application only in office buildings and not in retail buildings. Store area is leased based upon its rentable area, which includes an allocation of common areas by application of an R/U ratio. Store area was omitted from the BOMA 2010 Office Standard.

Under the 2010 Office Standard (ANSI/BOMA Z65.1-2010) a retail tenant is deemed to be an occupant. Occupant area is leased based upon its rentable area, which includes an allocation of service and amenity areas by application of a load factor.

Support:

BOMA Retail Standard ANSI/BOMA Z65.5-2012

Section 1: Scope and “Retail Building Types” in Definitions section

BOMA 2010 Office Standard ANSI/BOMA Z65.1 - 2010

Section 1B: Application and Use

ANSWERS TO 26 KEY QUESTIONS ABOUT THE 1996 ANSI/BOMA STANDARD METHOD OF MEASURING FLOOR AREA IN

OFFICE BUILDINGS, Question #25 “Does the Standard provide for the measurement of warehouse or industrial space? Does it cover a shopping center or strip mall?”

The Standard is intended to apply specifically to the measurement of office buildings. A method for measuring Store Area in office buildings is contained in the Standard. No provision is currently made for measuring any other types of buildings.

Contributed by: La Crosse, WI

Can the load factor that is calculated in the BOMA Global Summary of Areas spreadsheet (load factor A or load factor B, if using Method B) be arbitrarily increased to bring it up to the "Market Factor"?
(Applicable to ANSI/BOMA Z65.1-2010)

No. Under the BOMA 2010 Office Standard the load factor A (or load factor B if using Method B) cannot be increased to a value higher than the load factor calculated on the BOMA Global Summary of Areas spreadsheet to match a desired market factor for a building or for any floor in a building. When a market load factor comparable to load factor A or load factor B is used in the Global Summary of Area spreadsheet, the lesser of the market load factor and load factor A, (or load factor B if using Method B) is the capped load factor. Capped load factors are calculated on a floor-by-floor basis and may not exceed load factor A or load factor B for any given floor.

The value of the market load factor should be keyed into in the Global Summary of Areas spreadsheet at the top of Column R in Method A (or at the top of Column M if using Method B). Any changes to the formulas in the shaded portions of the BOMA Global Summary of Areas spreadsheet will result in rentable areas that do not conform to the requirements of the BOMA 2010 Office Standard.

Support: BOMA 2010 Office Standard ANSI/BOMA Z65.1-2010

Section 4: Measurement Methods, Optional Adjustment; capped load factor & establishment of a market load factor.

Section 5: Definitions and discussion of market load factor, load factor A, load factor B and capped load factor

Contributed by:  La Crosse, WI

Are the BOMA Global Summary of Areas spreadsheets available for downloading into Microsoft Excel™?
(Applicable to ANSI/BOMA Z65.1-2010)

BOMA does not distribute the Global Summary of Areas spreadsheets in Excel™ format.

The BOMA 2010 Office Standard includes illustrations of the Global Summary of Area spreadsheets, for both Method A and Method B, which explicitly show the Excel™ formulas required in every cell of the spreadsheet. The process of entering these formulas in Excel™ to build the spreadsheet will provide the user with an understanding of how it works and how to adapt it to buildings that contain a different number of floors. The user should familiarize themselves with the syntax and formulas employed by the spreadsheet.

BOMA Spreadsheets may be available from third parties over the Internet. When applying any spreadsheets acquired from third parties, the user must ascertain:

• Which BOMA standard it applies to (1996, 2010, etc.). The spreadsheets for previous BOMA Standards differ from those for the BOMA 2010 Office
• Whether the formulas contained therein are functionally identical to the formulas shown in the Global Summary of Areas Worksheets illustrated in the BOMA 2010 Office

For multi-building properties, a separate but compatible set of Global Summary of Area spreadsheets is contained in BOMA Best Practice #3, Inter-Building Service and Amenity Areas in Campuses & Multi-Building Sets.

Citations: BOMA 2010 Office Standard (ANSI/BOMA Z65.1-2010)

Refer to the last pages of the Illustrations in Section 7 for the Global Summary of Areas Worksheets.

Contributed by: William B. Tracy, AIA, MBA / Building Area Measurement LLC

Does BOMA International certify that an individual, company or system can perform BOMA calculations? If not, how can BOMA floor area measurements and calculations be certified? (Applicable to all BOMA Floor Area Measurement Standards)

BOMA does not certify, approve, or endorse any individual, firm, device, or software for the measurement of floor areas. Certification of floor area measurements and calculations may be made only by the entity that generated the area measurements and calculations.

BOMA International does not provide official interpretations of BOMA Standards but engages private firms as Official Interpreters who are qualified by virtue of their knowledge, experience, and resources to provide accurate interpretations of BOMA Floor Measurement Standards. The BOMA-Recognized Interpreters are listed on www.BOMA.org and they support forums to answer questions about the standards free of charge to all who purchased a copy of the standards.

BOMA International offers certificates of completion to individuals who have completed official BOMA floor area measurement seminars but that certificate testifies only to the fact that a certificate holder attended a BOMA floor area measurement seminar and does not testify to their experience, knowledge, or skill in performing BOMA floor area measurements.

Citations:

Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2010)

Industrial Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.2–2012)

Gross Areas of a Building: Standard Methods of Measurement (ANSI/BOMA Z65.3–2009)

Multi-Unit Residential Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.4—2010)

Retail Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.5—2010)

Mixed Use Properties: Standard Methods of Measurement (ANSI/BOMA Z65.6—2012)

Legal Notice: "BOMA does not certify, approve, or endorse any individual, firm, device, or software for the measurement of floor areas."

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

When a multi-occupant floor transitions to a single-occupant floor, should any areas classified as Service and Amenity Areas be reclassified as Occupant Area? (Applicable to ANSI/BOMA Z65.1-2010)

When using Method A of the BOMA 2010 Office Standard, Floor Service Areas such as: elevator lobbies and corridors (sometimes referred to as “Primary Circulation”) and Floor Amenity Areas (e.g., conference rooms, break rooms, etc.) should be reclassified as Occupant Area. However, Floor Service Areas, such as; restrooms, janitorial closets, electrical, telephone and mechanical rooms, should not be reclassified as Occupant Area. Furthermore, Building Service & Amenity Areas should not be reclassified as Occupant Area, since such areas benefit all occupants in a building.

When using Method B of the BOMA 2010 Office Standard, Base Building Circulation must never be reclassified as Occupant Area or influenced by any change in floor occupancy. Likewise, Floor Service Areas should not be reclassified as Occupant Area. Floor Amenity Areas, although rare, may be reclassified as Occupant Area, but one should consider that such a change will affect the rentable area of all occupants in the building. This can be avoided by originally classifying each Floor Amenity Area as an Occupant and separately determining how its area is applied and charged back to the occupants who benefit from it.

Citations: Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2010)

Legal Notice: BOMA does not certify, approve, or endorse any individual, firm, device, or software for the measurement of floor areas.

Contributed by: David Fingret, Extreme Measures

How should a building be physically measured in the field to create as-built floor plans or calculate floor areas? (Applicable to all BOMA Floor Area Measurement Standards)

Do abnormally thick exterior walls, such as the thick masonry walls found in some historic buildings, alter the measurement of any floor areas under the BOMA 2010 Office Standard or the BOMA Gross Area Standard? (Also applicable to ANSI/BOMA Z65.1-2010)

No. The rules for locating the IGA Boundary, the Measure Line and the Building Perimeter are specified in the BOMA measurement standards and do not change when the exterior enclosing wall of a building are abnormally large. There is no reference within BOMA Standards for dealing with abnormally thick enclosing walls or columns.

Building enclosing walls and columns are encroachments that are considered in the measurement of Plannable Area under other standards such as the Standard Practice for Building Floor Area Measurements for Facility Management (ASTM W 1836) published by the International Facility Managers Association.

Citations:

Gross Area of a Building: Standard Methods of Measurement ANSI/BOMA Z65.3-2009, Definitions of Exterior Gross Area, Measure Line, Construction Gross Area and Building Perimeter.

Office Buildings: Standard Methods of Measurement ANSI/BOMA Z65.1-2010, Section 1A & definitions of Interior Gross Area and IGA Boundary.

A Unified Approach for Measuring Office Space for Use in Facility and Property Management published by BOMA International.

Standard Practice for Building Floor Area Measurements for Facility Management (ASTM W 1836) published by the International Facility Managers Association.

Contributed by: Joe McDonnell, American Building Calculations.

Can Sidewalks be considered to be External Circulation area? (Applicable to ANSI/BOMA Z65.1-2010)

Sidewalks are not defined under the BOMA 2010 Office Standard but are considered to be public, unenclosed paved areas used by pedestrians at ground level adjacent to the exterior enclosure of a building. They may be covered or uncovered.

Sidewalks are usually not included in the Interior Gross Area (IGA) of the adjacent building. If a sidewalk has sufficient pedestrian traffic, it may constitute a Public Pedestrian Thoroughfare that affects the location of the IGA Boundary on that side of the building at that floor level. It is not uncommon for a sidewalk to provide the only access to a tenant area at the ground level, or to be used by a ground level tenant for display of goods or restaurant seating. These are not factors that are considered when determining where to establish the IGA Boundary of the office Building.

When a sidewalk is intended only for access to ground level tenants and is not used by other pedestrians who are merely passing by, then it may be classified as External Circulation so long as all the requirements are met under the definition of External Circulation in the BOMA 2010 Office Standard.

Citations: Office Buildings: Standard Methods of Measurement ANSI/BOMA Z65.1-2010, definitions of Interior Gross Area, Public Pedestrian Thoroughfare and External Circulation, Sections 5 and 6.

Contributed by: Joe McDonnell, American Building Calculations.

Should the Base Building Circulation boundary line be the same on all floors of a building? (Applicable to ANSI/BOMA Z65.1-2010)

Not necessarily. The purpose of Base Building Circulation (BBC) in ANSI/BOMA Z65.1-2010 Method B is to establish a minimum access and egress path on a floor by floor basis. The minimum path will vary according to the unique base building architecture of each floor. Since it is common for office buildings to have several floors with the same base building architecture, it is expected that BBC will be the same on those floors.  Conversely, BBC may vary on floors with a unique base building design.  For example, when BBC is interrupted by a significant structural element such as an atrium (void), the BBC will have to be adjusted to circumvent the void area.

BBC is not necessarily established by utilizing an actual, existing corridor configuration as a basis, since in most cases the existing corridor will not be designed with the minimum path required for access and egress. However, it is common practice to select the corridor configuration with the minimum path on a typical floor and then apply it to all floors with the same base building architecture.

Citations:  Office Buildings: Standard Methods of Measurement ANSI/BOMA Z65.1-2010, Sections 5 (Definitions)

Office Buildings: Standard Methods of Measurement ANSI/BOMA Z65.1-2010, Section 6.5 (Measurement Concepts)

Contributed by: Joe McDonnell, American Building Calculations

How many decimal places do I need to carry in my calculations in order to comply with the BOMA floor area measurement standards? (Applicable to all BOMA Floor Area Measurement Standards)

The BOMA standards do not specify how many decimal places must be carried for area units measured (square feet or meters) or for load factors.  The measurer must turn to local industry standards to determine their own best practices.

When measuring in square feet (imperial units) it is common practice to round final calculations to the whole square foot.  In a typical leasing agreement, a fraction of a square foot is typically not considered worth negotiating over.

When measuring in square meters (metric units) it is common practice to round final calculations to the first decimal place (1/10th of a square meter).  When one moves up to a square meter, this is a significantly larger area than a square foot. Just a tenth of a square meter is a little larger than a whole square foot.  In regions using the metric system, leasing agreements are often written with rounding to the first or second decimal place (1/10th or 1/100th of a square meter).

When rounding load factors it is necessary to understand and account for the relationship between the load factor and the area size.  The load factors have a varying potential to affect the final area since they are multipliers in the calculation.  The variance created by load factor rounding is directly affected by the size of the usable area the load factor is being applied to.  In order to maintain accuracy at the same level as the units you are rounding to, the load factor has to be carried out to as many decimal points as are needed to offset the largest area number's digit places before the decimal.  For example, an area that is only 900 square feet need only have the load factor calculated to the fourth decimal place to ensure accuracy to the whole square foot.  However an area of 900,000 square feet needs the decimal carried to the seventh place to maintain accuracy to the whole square foot.  So to ensure accuracy in the ones place (a whole square foot) you need to calculate the load factor out as many decimal places as equals one more than the number of units to the left of the decimal in the largest measurement to which the factor is being applied.

Alternatively if you are rounding to the first decimal place (a tenth of a whole unit) as commonly seen with square meters, you will need to count the number of digits left of the decimal in the largest area and add two to find your correct decimal place to calculate your load factors to.  This compensates for the rounding to a tenth of a whole unit.  See the illustration below.

Citations:

Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2010)

Industrial Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.2–2012)

Multi-Unit Residential Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.4—2010)

Retail Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.5—2010)

Mixed Use Properties: Standard Methods of Measurement (ANSI/BOMA Z65.6—2012)

Legal Notice:  "BOMA does not certify, approve, or endorse any individual, firm, device, or software for the measurement of floor areas."

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

Do the BOMA Standards require or recommend any specific methodology for measurements? For example, should measurements always originate from CAD files, or is paper OK? Should measurements always be field verified or is it OK to use existing drawings? (Applicable to all BOMA Floor Area Measurement Standards)

No. The BOMA Standards do not recommend any specific measurement methodology or data source to be used as a basis for BOMA area calculations. However, the various standards do not ignore the issue entirely either.

The BOMA Office Standard (ANSI/BOMA Z65.1-2010) and BOMA Industrial Standard (ANSI/BOMA Z65.2—2012) do state the following two paragraphs:

1. It is imperative that all measurements be fully documented. One of the hallmarks of superior property and facility management is good documentation of floor areas that provides accurate, reliable, and verifiable rentable area calculations.

2. It is common for a floor area calculated from the building plans (paper plans or CAD) to differ from the floor area measured on site using field measurements. (The Industrial Standard does not contain the words “paper plans or CAD” in parenthesis). This paragraph is also included in the BOMA Multi-Res Standard (ANSI/BOMA Z65.4-2010).

Similarly, the BOMA Gross Areas Standard (ANSI/BOMA Z65.3-2009) and the BOMA Retail Standard (ANSI/BOMA Z65.5-2010) contain this line:

It is not uncommon for an area calculated from the building plans to differ from the area measured on site.

In order to obtain accurate floor area measurements according to the BOMA standards, it is advisable to select an experienced and reputable firm that specializes in measuring buildings according to the BOMA standards.

Although the standards do not specifically mandate a methodology or data source, it is always advisable to ensure that the information used as the source for your BOMA area analyses are current and reliable, such as floor plans based on field measurements.

Citations:

BOMA Office Standard (ANSI/BOMA Z65.1-2010), Section 1B

BOMA Industrial Standard (ANSI/BOMA Z65.2—2012), Section 1

BOMA Multi-Res Standard (ANSI/BOMA Z65.4-2010), Section 2

BOMA Gross Areas Standard (ANSI/BOMA Z65.3-2009), Section 2: Preface

BOMA Retail Standard (ANSI/BOMA Z65.5-2010), Introduction

Contributed by: David Fingret, Extreme Measures Inc. 

The BOMA 2010 Office Standard suggests that an elevator lobby is classified as occupant area on a single occupant floor.  Does this apply to service elevator lobbies and secured elevator lobbies as well?

The definitions provided in the Standard suggest that an elevator lobby will be classified as either occupant area, base building circulation (Method B only), floor service area, or building service area.   

The Standard provides specific direction on classifying elevator lobbies for full floor occupants under the definition of occupant area.  The discussion section describes full floor occupants as having “effective use of the elevator lobby and any areas that would be required for corridors on multiple occupant floors so those areas are included in occupant area for full floor occupants under Method A … However, when using Method B (single load factor), the occupant area does NOT include base building circulation even though a full floor occupant generally has exclusive use and control of that area.”  These concepts are supported through Illustrations 11.5 and 12.3.  The general conclusion of this discussion is that on a single occupant floor, elevator lobbies are part of occupant area in Method A and are part of base building circulation in Method B. 

However, even on a single tenant floor, certain elevator lobbies are more appropriately classified as service areas (a portion of a specific floor/building that provides services that enable occupants to work on the floor/building).  If the area cannot be exclusively controlled by the full floor occupant it is a floor service area or building service area.  Examples may include a service or freight elevator lobby or other secured lobby that is primarily accessed by building engineers and other building maintenance personnel.  Another type of elevator lobby that would be classified as a service area is one that provides a life safety function as required by code, such as an area of refuge.  Even on a single tenant floor, these elevator lobbies should generally be classified as floor service area or building service area, not occupant area or base building circulation.

Citations: BOMA 2010 Office Standard (ANSI/BOMA Z65.1-2010)

Contributed by: Mitch Luehring, Gensler

When should I choose method A or B? (Applicable to ANSI/BOMA Z65.1-2010)

Either method A or method B can be used for a building at the discretion of the property owner or manager but must be used throughout the entire building uniformly.  It can be beneficial when choosing between the two methods to calculate both and compare how a particular building is affected by each standard before deciding which method to use.

Method A is also called the "Legacy Method" in the standard because it most closely matches the preceding BOMA Office standards.  Method A provides a unique load factor for each floor.  Method A is more familiar to many in the industry.  Since method A does not have base building circulation, floors with a single whole floor tenant typically see smaller load factors.

Method B offers a single load factor for the entire building. This can simplify dealing with a property and comparing occupant areas on different floors since, once calculated, there is only one load factor for the entire building.  Floor levels with many tenants on that level and large corridors can realize smaller load factors with method B due to extended circulation being allocated directly to occupants rather than being allocated through the load factor.   Also in buildings with a floor or floors that have a problematically high load factor, a method B measurement will distribute that floor's load building wide.

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

Are there any differences between Exterior Gross Area (EGA) in the BOMA 2009 Gross Area Standard and Gross Building Area (GBA) in the BOMA 1996 Office Standard? (Applicable to ANSI/BOMA Z65.1-1996)

Both Exterior Gross Area (EGA) and Gross Building Area (GBA) may be an appropriate method to calculate the leasable area for a single occupant building, however, each area includes and excludes different space types. Many of the space types below were not included or defined in the BOMA 1996 Office Standard but have been defined in the BOMA 2009 Gross and BOMA 2010 Office Standards.

Although certain space types are not specifically defined the BOMA 1996 Office Standard, the “Standard is intended to measure space that is fully enclosed”¹. Therefore these space types can be classified by their definition of enclosure.

Please refer to the Space Type Chart below:

Note: Space marked with asterisk (*) shall be disclosed

Citations:

BOMA 2009 Gross Standard ANSI/BOMA Z65.3.2009, Space Type Chart Page 6

BOMA 1996 Office Standard ANSI/BOMA Z65.1-1996

BOMA 2010 Office Standard ANSI/BOMA Z65.1-2010

¹Answers to 26 Key Questions about the ANSI/BOMA Standard of Measuring Floor Area in Office Buildings (Question 9)

Contributed by: Nate Olson, Stevenson Systems, Inc.

Using the BOMA Gross Area Standard, it’s not always obvious which protrusions on the building perimeter are decorative or structural. Does BOMA have any guidelines in determining this? (Applicable to ANSI/BOMA Z65.1-1996)

It is important to verify if protrusions are decorative or structural when establishing the building perimeter for the purposes of calculating the Construction Gross Area and the Exterior Gross Area. However, the BOMA Gross Areas Standard does not provide any guidelines for determining this. In most cases, a thorough visual inspection of the building’s architectural characteristics will provide enough evidence to make an accurate assumption. If you are unable to determine whether a protrusion is decorative or structural, it is advisable to review the original architectural or construction documents and, if necessary, consult with an architect or structural engineer for a definitive answer.

Citations: BOMA Gross Areas Standard (ANSI/BOMA Z65.3-2009)

Contributed by: David Fingret, Extreme Measures Inc.

If a "Recessed Entry" or "Door Setback" is more than one floor or one story high, is the area included within the Interior Gross Area (IGA)? (Applicable to ANSI/BOMA Z65.1-2010)

Should retail occupants in mixed use buildings be charged rent based on Occupant Area or Rentable Area? (Applicable to ANSI/BOMA Z65.1-2010)

The BOMA measurement standards do not make any recommendation as to how leases should be written. The purpose of the BOMA measurement standards is to detail how areas within a building should be calculated to determine, among other things, occupant, gross leasable, and rentable area. If a property is majority office and minority retail then the office building standard should be utilized. If a property is of a mixed use nature, then the ANSI/BOMA Z65.6 standard should be applied. In a mixed use property, common areas are not allocated to the retail components Gross Leasable Area (GLA).

Citations:

Office Buildings: Standard Methods of Measurement ANSI/BOMA Z65.1-2010

Retail Buildings: Standard Methods of Measurement ANSI/BOMA Z65.5-2010

Mixed-Use Properties: Standard Methods of Measurement ANSI/BOMA Z65.6–2012

Contributed by: Joe McDonnell, American Building Calculations

Do the BOMA Standards offer any guidelines with respect to occupant density? (Applicable to ANSI/BOMA Z65.1-2010)

The BOMA measurement standards do not consider nor do they offer any guidelines with respect to occupant density. Density plays no role at all when calculating building measurements. Such guidelines can be found in local building codes.

Citations: Not applicable

Contributed by: Joe McDonnell, American Building Calculations

How should Sky Lobbies or Elevator Transfer Corridors be measured? (Applicable to ANSI/BOMA Z65.1-2010)

Some high-rise buildings utilize express elevators with intermediate lobby floors where passengers transfer to local elevators before arriving at their destination floor level. 

Sky Lobbies, local elevator machine rooms, and elevator transfer corridors are a part of the building infrastructure that enables the building to exist in its configuration as a high-rise.  They are similar to any other auxiliary lobbies commonly allocated to building service area.  As such it is recommended that sky lobbies and elevator transfer corridors be classified as building service area.

Citation: 

SECTION 5: DEFINITIONS:

"Building Service Area - a portion of a building that provides services that enable occupants to work in the building.

Discussion: These areas include, but are not limited to the following areas that serve the entire building:

• main and auxiliary lobbies

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

Is the entire area within a Finished Rooftop Terrace included in the Boundary Area? Do all sides of a Finished Rooftop Terrace need to be above grade to be included in the Boundary Area? (Applicable to ANSI/BOMA Z65.1-2017)

The BOMA 2017 Office Standard defines a Finished Rooftop Terrace as a “definable area on a roof of a Building which has been legally renovated or designed to be occupied and enjoyed by people”. The intent of this definition is to include all areas within the peripheral boundary of the Finished Rooftop Terrace that are attributable to the Finished Rooftop Terrace even if there are certain areas within the Finished Rooftop Terrace that a person would not ordinarily inhabit. For example, an inaccessible garden within the area of the Finished Rooftop Terrace should be included in the area of the Finished Rooftop Terrace.

Areas within the peripheral boundary of a Finished Rooftop Terrace which cannot be attributed to the Finished Rooftop Terrace and which are not otherwise included in the Boundary Area according to the BOMA Office Standard, should be omitted from the area of the Finished Rooftop Terrace. For example, an unenclosed mechanical structure within the area of the Finished Rooftop Terrace should be excluded from the area of the Finished Rooftop Terrace.

For additional clarity, a Finished Rooftop Terrace must be a noncompulsory feature of the Building, which the Landlord has chosen to construct.

All sides of a Finished Rooftop Terrace must be at least one story above grade in order to be included in the
Boundary Area

Citations:

BOMA Office Standard (ANSI/BOMA Z65.1-2017), Section 3.1 Boundary Conditions, Page 21
BOMA Office Standard (ANSI/BOMA Z65.1-2017), Section 6.0 Definitions, Finished Rooftop Terrace, Page 100

Contributed by: David Fingret, Extreme Measures Inc.

Are areas beyond the floor opening considered when determining if an opening qualifies as a Major Vertical Penetration such as enclosed space for multiple small plumbing penetrations or the space of the enclosing walls that are part of the MVP? (Applicable to all BOMA Floor Area Measurement Standards)

When determining if a floor opening is or is not a Major Vertical Penetration (MVP), only the measurement of the opening itself should be considered. If no architectural evidence is available to measure the opening size but a floor opening is believed to exist, the measurement should be based on the enclosing walls or other building elements that are readily accessible in estimating the opening size.
The 2010 BOMA Office Standard defines a Major Vertical Penetration as “a floor opening in excess of 1 square foot (0.1 square meter).” Therefore, if the floor opening(s) are smaller than 1 square foot (0.1 square meter) then it is not measured as a major vertical penetration. Multiple small penetrations each less than 1 square foot (0.1 square meter) in size would not constitute an MVP even when grouped together in the same enclosure.

Citations: Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2010) [and other BOMA standards]

Definitions: Major Vertical Penetration - a floor opening in excess of 1 square foot (0.1 square meter) that serves vertical building systems or vertical occupant functions.

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

When an enclosing wall, or a component of that wall, is part of the primary structural support for a building, should that structural wall be ignored as an "other building support system necessary to the Building" when drawing the boundary condition, similar to columns as called out in Section 3.3 in Perimeter columns. (Applicable to ANSI/BOMA Z65.1-2017 and ANSI/BOMA Z65.1-2023)

When the standard states “… other building support systems necessary to the Building”¹ shall be ignored, this may refer to structural items that protrude into the building irregularly, like cross bracing or portal frames as examples, but is not intended to include structural bearing walls. This is supported in the following sentence in the standard as it talks about these disturbances to the Boundary Area; “Therefore, the Boundary Area is not disrupted by a column and will continue through the column, as if the protrusion does not exist.”¹ . Bearing walls would be continuous and not constitute a disruption abnormal from nonbearing walls measured Dominant Portions.

Therefore, bearing walls along the building enclosure should not be ignored, and should be measured as any other walls following the Dominant Portion of the Finished Surface when the Building Enclosures Dominant Portion is used in locating the extent of the Boundary Area.

Citation: 

¹ Section 3.3 Special Conditions - Perimeter Columns (Page 58)
Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2017)
Office Buildings: Standard Methods of Measurement (ANSI/BOMA Z65.1–2023)
See Illustrations 34a-34m of the standard and included attached for reference.

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO

Can walkways or “circulation alleys” inside a parking structure be counted as Building Common Areas? These are the marked pedestrian paths that connect parking spaces, mechanical rooms, and elevator lobbies, but are not separately enclosed spaces. The 1996 standard excludes parking, but doesn’t define what qualifies as part of the Parking Area versus a Building Common Area. (Applicable to ANSI/BOMA Z65.1-1996)

Under BOMA’s Office Building floor measurement standards, Parking Space (Parking Area) is included in the measurement but is excluded from Common Area and Rentable Area. This exclusion extends to the pedestrian circulation areas contained within those Parking Areas, even if they are marked or paved for foot traffic.

Circulation alleys within a parking structure, such as painted walkways that connect parking stalls to elevator lobbies or mechanical rooms, are considered part of the Parking Area, not a Building Common Area. The rationale is that these walkways exist primarily to support parking functions and are located within the Parking Area.

Context: The 1996 Standard Method for Measuring Floor Area in Office Buildings (Z65.1-1996) and later 2010, 2017, and 2024 Office Standards updates exclude “Parking Areas and associated driveways, ramps, and aisles.” While in the 1996 standard they don’t detail pedestrian circulation inside parking structures, the intent has consistently been to exclude all functional components of Parking Areas, whether for vehicles or pedestrians, unless they form part of the main building’s circulation network.

Contributed by: Garett Naff, AIA | Solid Tech Property Measurement, Denver CO