Field survey

Survey what is installed, not what was drawn

Photograph installed equipment, review extracted nameplate fields, and compare the field record with your plans and schedules. Keep missing information visible before the project handoff.

An MEP field survey records what mechanical, electrical and plumbing equipment a building actually contains — identity, ratings, age, location, condition, and what each unit serves. Review the capture while still on site, so an unreadable serial or missing capture can be checked before the visit ends.

A photograph becomes a unit record, is placed on the plan and compared against the design schedule, and leaves as an equipment schedule with its open items still listed.

What a survey has to produce

The deliverable is not a folder of photos. It is a record another engineer can pick up cold and design against: what each unit is, what it is rated for, how old it is, and where it sits in the system.

Most of that is printed on the nameplate. The part that is not — which air handler feeds which terminal units, which drive runs which pump — has to be worked out from tags, locations and layout, and it is what turns a list of machines into a system.

Where surveys go wrong

These six common gaps can be missed when review waits until after the visit instead of happening on site.

01: The plate was never legible

The plate was never legible

Painted over, corroded, or shot at an angle with flash glare.

02: One machine, six photographs

One machine, six photographs

Without consolidation those become six rows and a wrong equipment count.

03: The serial was never decoded

The serial was never decoded

A manufacture date or supported serial lookup was not recorded.

04: Nothing was tied to a location

Nothing was tied to a location

A row that cannot name a floor and room cannot support access planning.

05: Field and drawing were never compared

Field and drawing were never compared

Nobody finds the three undocumented fan coils until construction.

06: Complete was never defined

Complete was never defined

With no unresolved list, “finished” means “out of time”.

What comes off a nameplate

A survey capturing only make and model produces a list you cannot design from. These are the fields that decide whether the record is usable later.

01: Identity
02: Electrical
03: Capacity
04: Refrigerant
05: Age

Group	Captured	What it decides
Identity	Manufacturer, model, serial, unit tag	Ties the unit to a schedule row and a replacement part
Electrical	Volts, phase, FLA, MCA, MOCP, motor HP	Inputs to engineer review of electrical requirements
Capacity	Tons, MBH, CFM, GPM, static pressure	Decides whether a replacement is like-for-like
Refrigerant	Type and factory charge	Flags phase-out exposure on older equipment
Age	Printed manufacture date or supported serial lookup	Informs age assessment and replacement planning

Two different questions about a building

Surveying an existing building can mean two quite different jobs, and they need different tools.

The first is where things are. The run of a duct, the clearance above a ceiling, whether a replacement chiller fits through the door. That is a geometry problem that requires a suitable measurement or surveying method.

The second is what things are. The make, model, serial, ratings, age and condition of each unit, and what it serves. That is not a geometric property. Some information is printed on a plate; condition and system connections require additional observations.

Tagvexa answers the second question. It produces an equipment record: no dimensions, no clash detection, no point cloud. On a project that needs both, the scan and the equipment survey are separate pieces of work that happen to take place in the same building.

Field against design

Record drawings are a claim about the building. The field is the record. Equipment gets replaced, added and removed without the drawings following, so the differences need checking before design.

Compare conflicting values with their sources before deciding which to use. Record the discrepancy and its resolution in the handoff. The reconciliation guide works through each discrepancy class.

What firms ask first

What is an MEP field survey?

It is the site walk that records what mechanical, electrical and plumbing equipment is actually installed in a building — each unit's make, model, serial number, ratings, location, condition, and what it serves. It is the basis for retrofit design, due diligence, energy studies and replacement planning, because record drawings describe what was specified rather than what is standing there now.

How is this different from taking photos and filling in a spreadsheet afterwards?

Tagvexa organizes photos into equipment records and highlights reads that need review. With a connection, engineers can check the results while still on site, instead of discovering gaps during later transcription.

Do we need drawings or schedules for it to be useful?

No. Start an equipment inventory from photographs, then add plans and schedules when available. Design comparisons require those documents, and system relationships still need supporting evidence and engineer confirmation.

Is this laser scanning? Does it produce a 3D model?

No. Tagvexa organizes equipment information from photographs and project documents. It does not produce a measured 3D model, point cloud or clash analysis. Projects needing geometry and clearance measurements require a separate survey method.

What happens when it reads something wrong?

Review extracted fields against the source photo and correct errors in the equipment record. Flagged reads need attention, and apparently clear reads still need checking before design or handoff.

What do we get at the end of a survey?

Equipment records, source photographs, available nameplate fields, review findings and project exports. The deliverable depends on the captured evidence and engineer review; unavailable information remains a follow-up item.

See a survey become a deliverable

A walkthrough runs on a demo project: nameplate captures, the plan they sit on, the schedule they are compared against, and the record that comes out.

Explore the demo