Construction Drawings Sheet Numbering and Organization

In many cases, around the world, consultants and designers prepare construction drawings following their own drawing number standards, thus creating somewhat a confusion at the construction site. Many consultancy and design offices follow their own drawing numbering structure and refuse to implement a universal methodology, simply because this is how it is done for many years.

To this case, countries and standardization committees have prepared each their own drawing numbering structure and standards as a proposed solution to the case. For the last decade, we have seen several such national standards being prepared such as United States National CAD Standard, National BIM Standard, British CAD standards, Eurocode CAD standards etc. This further creates confusion amongst designers. Even though all follow similar pattern, they differ between them.

There are cases, where in large projects consultants come from around the world ( Architect from US, Interior designer from Spain, Structural Engineer from UK ), and each set of construction drawings have a different drawing numbering scheme.

After trying to review some of such CAD drawings / documents numbering standards, we are presenting here the US National CAD standard, which in my opinion is the simplest and easier to use from all the others.

Download article together with all related information

DOWNLOAD

Watch this presentation

Short video explaining how to use the best standard systen for construction sheet numbering.

COMPONENTS OF THE DRAWING NUMBER

As you can see from the example here, there are three (3) components to the drawing number structure.

The first two (2) letters are called the discipline designator indicating the discipline/design profession or trade.

The third (3rd) digit represents the sheet type of drawing (i.e. plan views, details, sections, schedules etc).

Finally, the last two (2) digits are basically the sequence number of drawings in the series of the same type. They can be any sequential number from 00 to 99 and the purpose is to place the drawings in order.

Complete Libraries

Now let’s dig deeper into explaining each of the three components.

DISCIPLINE DESIGNATOR

The discipline designator helps identify the trade/type of work each drawing is intended. For instance architectural, structural, electrical, mechanical, interior etc.

This helps the construction industry, distribute and identify drawings more easily. Furthermore, some construction trades might not need to review and understand drawings from all the consultants. For example, landscape sub-contractors don’t need to be distributed the interior drawings of the building.

Now, the discipline designator can be either a single letter or a double letter. Each letter signifies the specific trade of the drawing. Small projects usually use a single letter followed by a ” – ” in order to keep the format correct. But in large projects, usually double letter designators should be used. For example, electrical drawings will need to be separated into power drawings and lighting drawings as further sub-division.

Here is a list of the proposed discipline designation letters to be used.

DESIGNATOR

NAME

ADDITIONAL DESCRIPTION

Cover Sheet

G

General

Sheet list, symbols, code summary, etc.

H

Hazardous Materials

Abatement, handling, etc.

V

Survey / Mapping

B

Geotechnical

C

Civil

L

Landscape

S

Structural

A

Architectural

I

Interiors

Q

Equipment

F

Fire Protection

P

Plumbing

D

Process

M

Mechanical

E

Electrical

W

Distributed Energy

T

Telecommunications

R

Resource

Existing conditions / buildings

X

Other Disciplines

Z

Contractor / Shop Drawings

O

Operations

Furthermore, if double letter shall be used, the second letter can indicate the purpose of the drawing. For instance, an electrical drawing for power can be identified as EP, or mechanical plumbing drawings can be MP, architectural schedule drawing as AS etc.

DESIGNATOR

NAME

AD

Architectural Demolition

AF

Architectural Finishes

AG

Architectural Graphics

AI

Architectural Interiors

MP

Mechanical Piping

EP

Electrical Power

EL

Electrical Light

FA

Fire Alarm

SHEET TYPE

The third digit represents the sheet type, and it is a single digit number from 0 to 9. The sheet type is used to further organize drawings of a single trade into easier to find sections.

To better understand this, an architectural set of drawings consists of plan views, elevation views, sections, details, schedules, finishes etc. This 3rd digit helps separate these types. On a construction site, any sub-contractor might be searching for a specific section view, therefore this indicator helps anyone flip through large number of drawings and easily find the specific type of drawing he/she is looking for.

The table shows the numbers to be used for each type of drawing.

Number 7 and 8 are present in case a specific type of drawing is not listed and needs to be implemented.

Each type of drawing usually has different scale as well. For instance, plan views usually come at 1:100, elevations and sections 1:50 and detail drawings 1:10

As you can see, the numbering system organizes the types of drawings starting from the most general to more specific detailed drawings.

DESIGNATOR

NAME

0

General: Symbol legend, abbreviations, general notes

1

Plans

2

Elevations

3

Sections

4

Large Scale Drawings ( blown up ): plans, elevations, sections (NOT details)

5

Details

6

Schedules and Diagrams

7

User Defined

8

User Defined

9

3D Drawings ( isometric, perspective, photos )

SEQUENCE NUMBER

The last two digits on the drawing number act as the name suggests. It is basically a number indicating the sequence of the drawings and the order which they should be sorted.

It is basically a 2-digit number from 00 to 99.

In some cases, it is recommended to leave some sequential numbers unused in case more drawings need to be added in the future.

Here is some examples of standardized construction drawings.

NUMBER

SHEET DESCRIPTION

AD107

Architectural Demolition Floor Plan, seventh sheet

A for architectural, D for demolition, 1 indicates plan view, number 07 in sequence

A-204

Architectural Elevations, fourth sheet

I-316

Interior Section, sixteenth sheet

I for interior design drawing, 3 for section type, 16th number in the sequence.

FA601

Fire Alarm Diagrams, first sheet

P-102

Plumbing Floor Plan, second sheet

P for Plumbing trade, 1 for plan view, 2nd drawing

MH402

Large Scale HVAC Drawings, second sheet

MP501

HVAC Piping Details, first sheet

EP110

Electrical Power Plan, tenth sheet

EL103

Electrical Lighting Plan, third sheet

T-505

Telecommunications Details, fifth sheet