5.5 hours a week
People in a PlanGrid and FMI survey said they spend about five and a half hours a week hunting for project data, such as revised drawings.
PlanGrid and FMI survey, as reprinted by PHCP Pros (2018)DRAWING REVISION CHECKS
Build from
the new sheet.
Find and review drawing changes, including changes outside revision clouds. One list to assign, decide and sign off. An engineer confirms each impact.
© SheetshiftReal run · Gardner River High Bridge · S.4
Sheetshift · drawing revisions, checked
The change nobody cloudedis the one you pay for.
Find and review drawing changes, including changes outside revision clouds. Upload the old and new set; Sheetshift AI explains each change in plain words and gives your team one list to assign, decide and sign off.
7 sheets · 46 changes · 13 clouds foundfrom the Gardner River High Bridge case study
Opening the sheet
C-049Wording or number changedMedium
Design changeInside a cloud
Values: SureCoverage: Complete
The stirrup bar mark changed from #4B5 to #4B4 under revision 1.
- Old
- #4B5 Stirrup (typ.)
- New
- #4B4 Stirrup (typ.)
- bar mark: #4B5 Stirrup → #4B4 Stirrup
- stirrup bar mark: #4B5 Stirrup (typ.) → #4B4 Stirrup (typ.)
- revision triangle: nothing → 1
S-01 Workspace
The real workspace, on a real revision.
Pick a change, slide between the old and the new sheet, and read the card. No sign-in.
Review · Gardner River High Bridge
Open the tourS-02 The problem
Nobody keeps up with revisions by hand.
5 facts from people who measured it, each with its source.
796 questions, $1,080 each
On the average project in Navigant's study there were 796 questions to the designer (RFIs), each costing about $1,080 to answer.
Most of the projects in the study are in Australia and New Zealand.
Navigant Construction Forum, hosted by CMAA (2013)Six floors, then 12, then 15
At Ikoyi in Lagos, the structural engineers' institute said the building was designed for six floors, then 12, then 15, and that the engineering and management of those changes looked seriously inadequate. Officials gave different answers on how many floors were approved.
No source says a missed revision caused the collapse, and we do not say so.
ThisDay, quoting the institute's president (2021)The date in the title box
A concrete contractors' guide says that in many cases the only way to tell whether design drawings have been updated is to check the dates in the title boxes.
ASCC, The Voice newsletter (2022)0.38% to 12%
Estimates of rework range from 0.38% of contract value, measured at one contractor, to more than 12% on industrial projects. Studies count different things, so there is no single number.
The 12% figure is from a 1989 study of industrial projects.
ASCE Civil Engineering Source (measured) and the Construction Industry Institute (industrial projects) (1989)S-03 How it works
Two sets in, one change list out.
The numbers under each step are from the Gardner River High Bridge case study.
01
Bring both sets
Upload the old and the new drawing set as PDFs. Sheetshift tells you what it found: pages, sheets and the title box on each.
71 old sheets and 74 new sheets checked
02
Sheets are paired
Each new sheet is matched to its old version, also when it was renamed. New sheets and dropped sheets are listed.
7 pairs made, 64 old sheets not re-issued
03
Changes are found and explained
Lines, shapes and words are compared on each pair. Sheetshift AI writes what changed in plain words and says which work packages it may affect.
46 changes found, 12 design changes outside every cloud found
04
Your team decides
One change list: assign, decide, ask the designer, and let an engineer sign off. Export it or share a link.
7 changes ranked Check first
S-04 Core features
Every feature has a job in the review.
18 named features in 5 stages, shown here on a real run.
Stage 1 of 5
Bring the sets
Upload both sets and get them paired.
- Set Check
Checks both uploads: drawn or scanned, page sizes, sheet count, title box found.
- Sheet Match
Pairs old and new sheets, also renamed or renumbered ones, and lists new and dropped sheets.
D.3
F.3
S.2Stage 2 of 5
Find
Changes in lines, shapes and words, marked or not.
- Change Finder
Changes in lines, shapes and words, named by what they are: beam, column, slab edge, note.
- Cloud Check
Reads the designer's clouds and tags. Flags design changes nobody marked and clouds with nothing found.
- Revision Note Check
What the revision table says changed, against what did.
- Linked Sheets
Details and sections on other sheets that may now be out of step.
Stage 3 of 5
Understand
Plain words, with the work it may touch.
- Change Notes
One or two plain sentences per change, with the old and new values.
- Package Links
Which of your work packages a change may affect, why, and what to re-check.
- Check First
The review queue, most important first.
C-049Wording or number changedMedium
Design changeInside a cloud
Values: SureCoverage: Complete
The stirrup bar mark changed from #4B5 to #4B4 under revision 1.
- Old
- #4B5 Stirrup (typ.)
- New
- #4B4 Stirrup (typ.)
- bar mark: #4B5 Stirrup → #4B4 Stirrup
- stirrup bar mark: #4B5 Stirrup (typ.) → #4B4 Stirrup (typ.)
- revision triangle: nothing → 1
May affect Reinforcement: The stirrup bar mark changed from #4B5 to #4B4.
Re-check: Check the bar bending schedules and order lists for the correct stirrup mark.
Sheetshift AI suggests. Needs an engineer's confirmation.
Stage 4 of 5
Decide
Look, assign, decide, sign off.
- Overlay Viewer
Fade, swipe, side by side, colour overlay, blink. Jump from change to change.
- Team Routing
Suggests the responsible team for each change. One click to accept.
- Decision Log
Accept, ask the designer, needs an engineer, no effect, false alarm. Who, when and why.
- Engineer Sign-off
Only a person with the Engineer role can confirm an impact.
- RFI Draft
A question to the designer with the crops and values attached.
Decision
Accept as issuedAsk the designer (RFI)Needs an engineer's checkNo effect on our workNot a real change (false alarm)
Only an Engineer confirms an impact.
Stage 5 of 5
Share
One list for the whole team.
- Change Register
One list: export to Excel, CSV and PDF with crops, and share a read-only link.
- Issue Brief
One page for each revision, and one short brief for each team.
- Ask Sheetshift
Ask a question about this revision and get an answer with change numbers.
- Noise Filter
Learns from your false alarms. Groups look-alikes and never hides them.
ChangeWhat changedCloudFirst
C-049The stirrup bar mark changed from #4B5 to #4B4 under revision 1.Inside a cloudMedium
C-061Bar marks #6S8 and #6S16 were changed to #4S8 and #4S16 respectively, with revision 1 tags added.Not markedHigh
C-042The general notes list was expanded from 6 notes to 10 notes, adding detailed descriptions for repairs, rivets, and quantities.Inside a cloudHigh
C-056The bar size changed from #4S13 to #4S7.Inside a cloudHigh
S-05 Cloud Check
Changes nobody marked.
The designer's cloud is a free answer key, and the change outside it is the edge.
Inside a cloudC-049: The stirrup bar mark changed from #4B5 to #4B4 under revision 1.
A designer clouds what they changed. Sheetshift reads the cloud, then sorts the design changes it finds into three lists.
- Inside a cloud. The designer marked it.
- Not marked. A design change outside every cloud found. These are the ones that can get built from the old sheet.
- A cloud with nothing found. Either the designer clouded something that did not change, or we missed it. A person looks.
- inside a cloud
- 9
- design changes outside every cloud found
- 12
- clouds with nothing found
- 0
Counted on Gardner River High Bridge. Listed apart, not counted as design changes: 5 revision records, 12 designer marks, 47 plotting-noise differences. A person judges each one from the crops below.
Found outside every cloud, with the crops
C-061 · Bar marks #6S8 and #6S16 were changed to #4S8 and #4S16 respectively, with revision 1 tags added.
S-06 How Sheetshift AI works
The AI reads. Code checks. An engineer confirms.
Sheetshift AI
Reads and explains
Reads the title boxes, the clouds and the before and after of each change. Writes the note, ranks what to check first and drafts the question to the designer.
Code
Measures and checks
Lines up the sheets, finds the differences, and checks each number the AI writes against the sheet. If a value is not on the sheet, the note is not shown.
An engineer
Confirms
Every impact stays may affect until a person with the Engineer role confirms it. The AI never states cost, schedule or safety.
- notes that passed the value check first time
- 45
- rewritten, then passed
- 1
- shown as the sheet's own words
- 0
S-07 Case studies
Real drawing sets, run through the real app.
Public bid drawings and the addenda that changed them. Nothing here is made up.
Bid plans against Amendment 3
Fryingpan Creek Bridge
15 sheets paired, 106 changes found, Mount Rainier National Park, Washington.
- sheets paired
- 15
- changes found
- 106
- clouds found
- 23
The Federal Highway Administration and the National Park Service are not Sheetshift customers and did not take part. These are public bid drawings prepared by the US Government, which carry no copyright, run through Sheetshift for transparency.
Read the case studyBid plans against Amendment 1
Gardner River High Bridge
7 sheets paired, 46 changes found, Yellowstone National Park, Wyoming.
- sheets paired
- 7
- changes found
- 46
- clouds found
- 13
The Federal Highway Administration and the National Park Service are not Sheetshift customers and did not take part. These are public bid drawings prepared by the US Government, which carry no copyright, run through Sheetshift for transparency.
Read the case studyS-08 Measured accuracy
What we measured, and how many.
Changes we planted on real sheets
420 edits planted on 56 real sheets, in 2 ways of drawing the same sheet. This is a test we run on ourselves, not a measure of real revisions.
Three measures, shown apart
- Detection395 of 420 (94%)
- Planted edits Sheetshift found, out of the edits planted.
- Interpretation completeness23 of 23 (100%)
- Found edits whose old and new value both appear in what Sheetshift says about the change, out of found. Measured on 26 planted edits in real ruled tables (23 found); n is small.
- Value accuracy22 of 23 (96%)
- Explained edits where one detail or table cell holds exactly the planted old and new value, out of explained. Measured on 26 planted edits in real ruled tables (23 found); n is small.
| How the sheet is drawn | Found, out of planted | False alarms per sheet |
|---|---|---|
| Same plot | 196 of 210 (93%) | 0.5 |
| Sheet shifted on the page | 199 of 210 (95%) | 0.5 |
Real revisions against the designers' own lists
The architect or engineer wrote down what changed. Each written item is matched to the changes Sheetshift found. Matched by Sheetshift, not yet checked by a person.
- Fryingpan Creek Bridge9 of 9 items
- Gardner River High Bridge6 of 7 items
Not measured yet, so not claimed: Check First, Package Links and Team Routing against an answer key, and runs on very large sets.
S-09 Who it's for
For the people who build from the sheets.
The morning a bulletin lands
General and main contractors
A revised sheet reaches the site team late, or a change inside it is never seen, and the work is built from the old version.
Before the rebar order goes out
Specialist subcontractors
You fabricate or install from a sheet that has quietly changed, and acting on a change without a record can cost you the right to claim.
When the client asks what changed
Engineering consultancies and QS firms
You must show what changed, who reviewed it and what was decided, and the answer is spread across emails and marked-up PDFs.
The Monday review of open changes
Project managers
Nobody can say which changes are still open, who owns them, or whether the designer was asked.
S-09.1 Where it fits
Where Sheetshift fits.
Three kinds of tool compare drawing revisions. They are built for different buyers.
PDF overlay tools
Lay the old sheet over the new one in colour, so you see where the ink differs. You still write the list of what changed.
- Built for
- Teams that review the sheets and keep the change list themselves.
- Priced
- Usually per person, per month or per year.
Platform AI
AI tools inside a wider construction platform, with the review of drawing changes as one tool among several.
- Built for
- Large contractors.
- Priced
- One fee set by the company's yearly construction volume, on request.
Sheetshift
Finds and explains the changes between two issued PDF sets, then keeps a review register: each change with an owner, a decision and an engineer's sign-off.
- Built for
- Structural subcontractors and consultancies working from issued PDF sets.
- Priced
- Per active project, in naira first. Reviewers are unlimited.
Read from the public product and pricing pages of each kind of tool.
S-10 Trust and data
Your drawings stay yours.
Your drawings stay in your project
Files and the change list belong to the project you uploaded them to. Only people you add can open them.
Never used to train any AI
Sheetshift AI reads your sheets to answer for your project. Nothing you upload is used to train any AI.
Delete any time
Delete a project and its files, crops and change list go with it.
Who can see and decide
Owner, Engineer, Reviewer and Viewer. Only an Engineer can confirm an impact. Viewers can read and cannot change anything.
S-11 Pricing
Priced by active project, in naira.
Every plan has every Sheetshift AI feature. Unlimited reviewers. You pay for active projects, not seats. Month to month. Cancel any time.
Try
₦0
once
- 1 project
- 1 comparison, up to 30 sheet pairs
- Every Sheetshift AI feature
- Unlimited reviewers
Project
₦30,000
about $21, a month, per active project
- 200 sheet pairs compared a month
- Every Sheetshift AI feature
- Unlimited reviewers on the project
- Excel, PDF and share links
Team
₦100,000
about $71, a month
- Up to 5 active projects
- 1,000 sheet pairs compared a month
- Shared work packages and teams
- Team briefs for every revision
Company
From ₦350,000
about $248, a month
- 20 or more active projects
- Larger allowances
- Help setting up your packages and teams
- Talk to us about your sets
S-12 Questions
Plain answers.
What is a change nobody marked?
A change outside every revision cloud. The cloud is the wavy outline a designer draws around what they changed. Sheetshift lists the changes it finds inside a cloud, partly inside, and outside. A design change outside every cloud is one nobody marked. Revision-table rows and the clouds themselves are listed apart.
Does it replace my engineer?
No. Sheetshift AI finds and explains changes and says which work packages they may affect. It never states cost, schedule or safety. Only a person with the Engineer role can confirm an impact in the app.
Which PDFs work?
PDFs exported from drawing software, and scanned PDFs on one side. Sheetshift checks both sets when you upload them and tells you what it found: pages, sheets and whether the title box was found. A scanned sheet is marked as checked by picture only.
How does it know which sheets go together?
It reads the sheet number in the title box. If the number is drawn as lines, Sheetshift AI reads the title box picture. If a sheet was renamed or renumbered, it proposes a pair and asks you to confirm it before it looks for changes.
Can I trust the notes it writes?
Every number, size and label in a note must appear on the sheet. If one does not, the note is written again once. If it still fails, the app shows the old and new words as they are on the sheet instead of a note.
What is an active project?
A project with at least one comparison in the month. A project you do not compare in that month costs nothing for that month. Reviewers are unlimited on every project.
Do you train on my drawings?
No. Your drawings and your change list stay in your project and are never used to train any model. They are deleted when you delete the project.
What happens when it is not sure?
It says so, with two labels. Values (Sure, Fairly sure or Check this) says whether the old and new words and numbers were read right. Coverage (Complete, Partial or Not checked) says whether everything that differs inside the change is explained. A list of what was not checked, such as a sheet it could not line up, comes with each comparison.
S-13 Start
Check your next revision before your team builds it.
Upload the old and the new set. The first comparison is free, up to 30 sheet pairs.
Questions? Write to hello@sheetshift.ai