Should we convert our whole archive to CAD?

Rarely. Convert what facility work depends on — current plans and maintained systems — and scan the rest for reference. Triage keeps the project affordable and useful.

Can drawings on aperture cards be converted to CAD?

Yes. The cards are scanned to image files, then the drawings are redrafted to their written dimensions like any other scan.

Do converted drawings match the building as it is today?

Only as far as the source drawings do. For areas that matter, combine conversion with field verification or your own redlines.

Digitizing a facility's drawing archive: where to start

Surpreet Mahal, Director · October 31, 2026 · 7 min read

Start by inventorying the archive and deciding which drawings you actually need as CAD — usually current floor plans and the MEP systems you maintain — rather than converting everything. Scan the rest for reference, agree one CAD standard, and convert in priority order, checking each batch against the field before relying on it.

Who this is for

Hospitals, universities, utilities and government agencies often hold decades of drawings across plan rooms, flat files, microfilm, aperture cards and old CD-ROMs — original construction sets plus every renovation since. Facility teams need that information for renovations, life-safety work and space management, but it is spread across media and eras.

Step 1: inventory before you convert

List what exists by building, discipline, date and medium (paper, mylar, microfilm, aperture card, PDF, old CAD).
Identify the most recent sheet for each area — later renovations often supersede the original set.
Note what is missing; gaps may need field verification rather than conversion.

Step 2: triage — not everything needs to be CAD

Convert to CAD: current floor plans, the MEP systems you maintain, life-safety plans and anything about to be renovated.
Scan only: superseded sets, details nobody edits, and historical records kept for reference.
This usually shrinks the conversion scope dramatically without losing anything.

Step 3: set one CAD standard first

Agree layer names (the US National CAD Standard is a common choice), title blocks, text and dimension styles, and room numbering before any conversion starts. Converting in batches without a standard creates a second clean-up project later.

Step 4: microfilm and aperture cards

Aperture cards — a frame of 35 mm microfilm mounted in a punched card — are common in government and utility archives. They are scanned on dedicated card scanners to TIFF, then converted like any other scan. Resolution is limited by the film, so fine text is checked carefully and anything unreadable is logged.

Step 5: convert in batches and verify

Start with one building or floor as a pilot to settle the standard and the review process.
Overlay each delivered drawing on its source and spot-check written dimensions.
Walk critical areas in the field; legacy drawings often differ from what was actually built.

GeoNaksha has converted legacy drawings for US hospitals, power plants, engineering firms and government clients since 1997. We work to your standard under NDA, and you can start with a free sample of one sheet.

Questions

Should we convert our whole archive to CAD?: Rarely. Convert what facility work depends on — current plans and maintained systems — and scan the rest for reference. Triage keeps the project affordable and useful.
Can drawings on aperture cards be converted to CAD?: Yes. The cards are scanned to image files, then the drawings are redrafted to their written dimensions like any other scan.
Do converted drawings match the building as it is today?: Only as far as the source drawings do. For areas that matter, combine conversion with field verification or your own redlines.