How to Mark Up Construction Drawings on iOS or Android devices

Learn how to use Xodo on iOS or Android to open a drawing sheet, add markups, confirm revisions, and save a copy. This guide shows you how to mark up and send construction drawings back to your project team without creating revision confusion.

Drawing issues happen every day on construction projects:

• A duct installation doesn't match the issued drawing.
• An inspector notices a missing penetration detail during a site walk.
• A construction manager needs to send punch observations before leaving the project site.

The challenge is not simply adding notes to a PDF. The challenge is documenting the observation on the correct sheet, preserving context, and returning a marked drawing that your colleagues can understand.

With Xodo, field teams can review drawings, add markups, and share PDF copies with complete and clear redlines and annotations showing corrections, changes, or comments before the drawing is updated.

This guide will show you:

• What to prepare before marking up construction drawings
• How to mark up construction drawings using Xodo
• When to move from mobile markup to desktop software
• Answers to common questions

What should you prepare before marking up construction drawings in the field?

A successful field markup starts before you arrive on site. Take a few minutes to prepare the right drawing and confirm project details to prevent revision confusion later on.

i) Install Xodo PDF editor app

• For iPad and iPhone users: get Xodo for iOS.
• For Android users: get Xodo for Android.

Having the app installed and tested before a site visit lets you focus on your drawings instead of troubleshooting in the field.

ii) Download the correct drawing

Ensure you have a local copy of the PDF file stored on your mobile device:

• Open the latest drawing before leaving the office.
• Verify that the file opens correctly in Xodo.
• Confirm the sheet number and revision date.
• Store a local copy if your workflow requires offline access.

A few minutes spent verifying the PDF drawing can save a return trip caused by marking up an outdated sheet.

iii) Confirm project information

Before adding any field notes, check the following items:

• Sheet number
• Drawing title
• Issue date
• Revision number
• File name

This quick review creates a clear audit trail and helps AEC professionals understand exactly which drawing the markup refers to.

With everything above checked, you’re now ready to add actionable redlines using Xodo Mobile.

How to mark up construction drawings in Xodo Mobile

To markup construction drawings on iOS and Android devices with Xodo, follow the steps below. The steps below show an Android device, but are identical to those for iOS.

1. Open Xodo Mobile and your construction drawing

If you didn't already, download Xodo for iOS or Android.

• Install and open the app.
• Open your PDF drawing.
• If you can't locate it, tap on "+" and then Open file to search other locations.
• Once opened, navigate to the page in the file that needs review.

Tip: Use pinch-to-zoom controls to review details without losing context. Construction drawings often contain dense information, so zooming into the specific area helps create precise comments.

2. Access tools for marking up your drawings

To start marking up your drawing or blueprint, open the markup toolbar and select the tool that best matches the observation you're documenting.

• Tap the markup toolbar.
• Select the annotation or drawing tool you want to use.

Annotation tools

• Highlight corrections, code compliance issues, and revisions.
• Add comments for field issues and actions.
• Indicate site conditions with freehand drawings.
• Underline outdated, conflicting, or incorrect text.
• Add review sticky notes and punch-list items.

Drawing tools

• Add shapes to mark boundaries, conflicts, or review areas.
• Create cloud annotations to highlight issues and revisions.
• Insert arrows and polylines to pinpoint locations.
• Draw on your PDF and add sketches to show field changes.

Measurement tools:

• Calibrate scale for accurate drawing measurements.
• Measure distances between walls, equipment, or utilities.
• Measure perimeters for layouts and site planning.
• Colour code measurements for flooring, roofing, or concrete work.

Using the right tool makes your feedback easier to understand and helps reviewers identify issues faster during project reviews.

3. Add your markups and comments

Document the field observation directly on the PDF drawing:

• Identify the area that requires attention.
• Add your annotation or redline.
• Include any context or follow-up action needed from the reviewer.

Choose the markup that communicates the issue most clearly. Use clouds or shapes to define the affected area, arrows to pinpoint a location, freehand ink to sketch a site condition, and text notes to explain the issue or required action.

For a clear redline, combine them. For example, circle the problem with a cloud, point to it with an arrow, and add a note describing the next step.

Tip: Use a stylus for more precise markups

You can also use a stylus to add markups in Xodo Mobile. The PDF editor supports Apple Pencil, Samsung S Pen, Pixel Pen by Google, and touch input. A stylus can help you place redlines more precisely on detailed construction drawings or dense sheet layouts.

Read how to use stylus as pen mode.

4. Confirm your notes and share the file

• Review all comments and revisions.
• Tap on the 3 vertical dots in the upper right hand corner.

You'll then have a few options:

• Save your annotated drawing and share it manually via email on your device.
• Tap on Share and send the PDF to others using your messaging and sharing apps.
• Tap on Export for more options. You can flatten the PDF, add a password, or reduced its file size.

Before sharing the PDF drawing, save it with a clear file name that includes details such as the project identifier, sheet number, revision, and date.

Reopen the saved PDF to check that every markup and comment appears correctly, then share it through your organization’s approved workflow.

For more details, check our our guide on using how to edit and view PDFs with Xodo.

When should you move from mobile markup to desktop?

Xodo Mobile is great for capturing field observations and redlines on site. For more detailed review workflows, continue in a desktop editor like Xodo PDF Studio.

Use a desktop PDF editor when you need to:

• Review complex drawing sets on a larger screen
• Manage multiple comments and markup threads
• Measure PDF drawing objects in detail
• Coordinate reviews with project stakeholders
• Perform complex multi-sheet document reviews
• Compare construction drawing revisions in PDF

A consistent desktop workflow, from preparing the correct drawing through sharing the marked PDF, helps reduce revision errors and keeps field feedback actionable.

Frequently asked questions

1. What is the best way to mark up construction drawings on an iPad?

Download the Xodo PDF editor app to your iPad. Then, open the PDF drawing, verify the sheet revision, add annotations such as notes, arrows, shapes, and clouds, then save and share a clearly named copy.

2. Can I use Xodo to mark up blueprints on an Android tablet?

Yes. The Xodo app allows you to open, view, review and annotate PDF construction drawings using touch or stylus input on Android tablets and phones.

3. Should I use freehand markups or text comments?

Use freehand redlines when a sketch communicates the issue more clearly. Use text comments when accuracy and traceability matter. Many field reviews benefit from both.

4. How do I avoid marking up the wrong revision?

To avoid marking up the wrong revision, check the sheet number, issue date, revision identifier, and file name before adding markups, and again before sharing the marked PDF.

5. Do I need a stylus to mark up construction drawings?

No, you don't need a stylus. Xodo supports touch-based annotation, as well. A stylus can help with precision, but it is not required.

6. When should I use desktop review tools instead of mobile markup?

Move to desktop review when you need advanced comparison, comment management, or larger-scale document review. You should use mobile workflows for field observations and redlines.

Turn field observations into actionable insights with Xodo

A clear markup is only useful if it reaches the right person with the right context.

Follow a simple workflow: confirm the sheet, document the observation, verify the revision, save your changes, and share the marked PDF.

With Xodo Mobile, you can complete that entire process from the field on iOS or Android. Test it out today on your current project drawing.