Here's a pattern we see constantly: a building gets new access points, mounted where the old ones were (or wherever the cabling happened to be), and within a month the complaints are the same as before. Dead spots in the same corners. Slow speeds in the same conference room. Calls dropping in the same hallway.

The equipment wasn't the problem. The design was. And the design is what a site survey is for.

What a site survey actually measures

A Wi-Fi site survey models or measures how radio signal behaves in your specific building, so access points can be placed, configured, and channeled to meet your requirements. A good survey answers:

  • Coverage — is signal strong enough everywhere it needs to be, including stairwells, elevator lobbies, and back-of-house?
  • Capacity — can the network handle the number of devices in your busiest spaces at your busiest times?
  • Interference — what neighboring networks, equipment, or building materials degrade performance?
  • Roaming — do devices move cleanly between access points as people walk around?
  • Application needs — voice, video, scanners, real-time location, and medical devices all have different requirements.

The three kinds of survey

1. Predictive survey

Software models RF behavior using a floor plan, wall materials, and access point specifications. It's fast and inexpensive, and ideal for new construction or budgeting. Its accuracy depends entirely on how accurately walls and materials are modeled — and buildings rarely match their drawings perfectly.

2. Pre-deployment on-site survey (“AP on a stick”)

An engineer temporarily places a real access point at candidate locations and measures actual signal through the actual building. It catches what a model misses: metal shelving, mirrored glass, elevator shafts, fire doors, and renovations that never made it onto the drawings. It's especially valuable in warehouses, healthcare facilities, older buildings, and anywhere with unusual construction.

3. Post-installation validation survey

After installation, an engineer walks the building to confirm the network actually performs to design: coverage, signal-to-noise ratio, channel overlap, and roaming. This is the step most often skipped, and the one that gives you proof the project delivered what you paid for.

Our rule of thumb: predictive for planning and budget, on-site validation for anything mission-critical, and a post-installation survey every time.

What skipping the survey really costs

A survey is a small fraction of a wireless project's total cost. Skipping it tends to cost far more:

  • Re-cabling and moving access points after the ceilings are closed — often more expensive than the original install.
  • Over-buying hardware to compensate for poor placement, which also creates co-channel interference and makes performance worse.
  • Lost productivity from scanners, tablets, and phones that disconnect in the places staff use them most.
  • Support time chasing problems that are really design flaws.
  • Failed downstream projects — indoor cellular over Wi-Fi, location services, and voice all assume a well-designed RF foundation.

What you should get at the end

  1. Coverage and signal heatmaps for each floor, in the band(s) you'll use.
  2. Recommended access point locations, mounting, and antenna types.
  3. Channel and power plan.
  4. Cabling requirements for each access point location.
  5. A bill of materials tied to the design.
  6. For validation surveys: as-built results compared against design targets.

When to re-survey

Buildings change. Re-survey after major renovations, when you add a lot of new devices or applications, when moving to a new Wi-Fi generation (especially adding 6 GHz), or whenever users report recurring problems in the same areas.

The bottom line

A site survey isn't overhead — it's the design. Spend a little up front and you buy the right number of access points, put them in the right places, and get a network that works the day it goes live.