Permit drawings and construction drawings, and how they differ

Two readers, one set of drawings

A permit set and a construction set are usually the same drawings issued for two different readers. The permit set is written for the plan checker, who reads it for compliance with the building code, the zoning code and the other regulations the department enforces. The construction set is written for the contractor and the trades, who read it for quantities, dimensions, materials and sequence.

On a well-managed multifamily project the two diverge as little as possible. The building department approves one set; the contractor builds from that set plus a documented list of changes. Trouble starts when the field set and the approved set differ and nobody can say how.

What a permit set holds

A permit set holds everything the department needs to approve the building, and on a multifamily project that is most of a full CD set:

• the general sheets: code analysis, occupancy and construction type, allowable area and height, exiting, fire separations, accessibility plans and the unit matrix;
• the site plan with setbacks, easements, dedications and utility connections;
• every floor plan, the roof plan, elevations and building sections;
• the rated assemblies and the details plan check needs to verify them;
• the door and window schedules, where egress, ratings and accessibility live;
• the structural, plumbing, mechanical, electrical and energy documents each reviewer checks.

What a permit set can leave lighter is the information only the builder needs: finish selections, casework elevations beyond what accessibility requires, some trim and interior details. Practices differ on how much of that they hold back. Holding back a sheet a reviewer needs costs a round of corrections; issuing interior details early costs revisions later.

What plan check reviews

Plan check reviews the set for compliance. The reviewer does not check whether the building is buildable, priced or coordinated beyond what the code reaches. In the City of Los Angeles the Department of Building and Safety reviews a multifamily set with its standard correction list for R1 and R2 occupancies, a document organized from the permit application and clearances through zoning and then the building code by topic (LADBS R1 and R2 correction sheet). The LADBS corrections guide walks through how that sheet is answered.

Building plan check is rarely the only review. On a multifamily project the fire department, the planning department, public works and the utilities often review parts of the same set, and each can ask for changes. A change made for one reviewer has to be sent to every other reviewer whose sheets it touches, or the approved sets stop matching each other. The LADBS clearances guide lists the departments that commonly review a multifamily permit in Los Angeles.

Approval comes in the form of an approved, stamped set held by the department and returned to the applicant. That approved set is the legal reference for every inspection.

What changes after the permit

Deferred submittals

Some parts of a building are designed by the contractor's team after the permit: fire sprinklers, fire alarm, trusses, some curtain wall and guardrail systems. The International Building Code lets the building official approve these as deferred submittals. The registered design professional in responsible charge lists them on the construction documents, reviews each one when it comes in, and forwards it to the building official with a note that it is in general conformance with the building's design; the work it covers is not installed until the department approves it (IBC 107.3.4.1).

On the drawings, that means a deferred submittal list on a general sheet, kept current through construction.

Changes in the field

Any change that takes the work away from the approved documents goes back to the building department as an amended set before it is built. The International Building Code states it in Section 107.4: work is installed per the approved construction documents, and changes that do not comply with them are resubmitted for approval.

Changes reach the contractor through a short list of instruments:

Supplemental permits in Los Angeles

LADBS handles changes to approved plans through a supplemental permit. The submittal includes a copy of the original approved plans, a narrative of the changes, and the changes clouded on the plans (LADBS submittal screening, determination of completeness). The revised plans go back through review before the change is built, so a change found late costs a review cycle the schedule has to absorb.

The practical consequence is that every revision raises two questions: does it change what the department approved, and if so, which reviewer has to see it.

Keeping the two sets together

A few habits keep the approved set and the construction set from drifting apart:

1. One model, one sheet list. The permit set and the construction set are issues of the same Revit model, never parallel files. A revision made in one exists in the other.
2. Revision discipline. Every change after approval gets a revision number, a cloud and an entry in the revision block, so anyone can see what moved since the department stamped the set. The title-block check includes this.
3. A permit-impact column in the log. Each supplemental instruction, revision and RFI response is tagged yes or no for permit impact on the day it is issued, with the reviewer named when the answer is yes.
4. The deferred submittal list on the cover sheet, updated as each item is approved.
5. A conformed approved set. After each supplemental permit, the field set is updated so the stamped drawings and the drawings on the jobsite match.

The approved set on site

Inspections are made from the approved set. Building inspectors check the work in the field with the stamped drawings the department approved, so the jobsite copy matters as much as the office copy. A crew building from an unstamped revision the department never saw is building work an inspector can reject.

That is why the conformed approved set exists. After each supplemental permit or approved revision, the jobsite set is updated so the stamped sheets and the sheets the trades use say the same thing, and superseded sheets are marked or removed.

Record drawings at the end

When construction ends, the changes made in the field are gathered into a record set, often called as-built drawings when the contractor marks them up and record drawings when the design team updates the model to match. The owner keeps the record set for operations, future alterations and the next permit on the building. On a multifamily building with dozens of repeated units, an accurate record set saves the next design team weeks of field measuring.

Two sets, one schedule

The gap between permit and construction sets also shows up in the schedule. A permit set is often issued before the construction set is complete, because plan check takes weeks to months and the owner wants the clock started. The construction set then keeps developing during plan check: interior details, finish selections, casework and coordination items. When the permit comes back, the two have to be merged: the approved sheets with their corrections, and the construction sheets with their development. The merge goes smoothly only when both live in one model and every change gets a revision number from the start.

Which set to hand off

When a practice is short on hours, the question is often which of these sets to give to an outside team. Two packages tend to work well:

• the permit set's remaining sheets once the design is settled at DD, with the practice keeping the code analysis and the decisions;
• plan check corrections and the revisions that follow, which are bounded, deadline-driven and best answered by whoever drew the sheets.

Where the studio fits

TECTO Studio draws permit and construction sets in your Revit model and answers plan check corrections on the sheets it drew, with a dated log of every change. The plan check corrections page describes the work.

Sources

• IBC 107.3.4.1, deferred submittals (UpCodes)
• International Building Code, Section 107.4, amended construction documents
• LADBS: R1 and R2 occupancies plan check correction sheet
• LADBS: Building plan check submittal screening, determination of completeness
• LADBS: Regular plan check