Commercial Wi-Fi surveys
A Wi-Fi survey turns radio behaviour into a design you can build from and a number you can budget against. We run predictive, on-site and validation surveys on Ekahau across UK commercial sites — and then we install what the survey specifies.
What a Wi-Fi survey actually is
A Wi-Fi survey is a measurement exercise. Radio does not behave the way a floorplan suggests: a stud wall costs you a few decibels, a lift shaft costs you most of a signal, and a warehouse full of steel racking behaves like a completely different building once the pallets are in. A survey establishes what the radio environment is really doing, and turns that into a design — where the access points go, what they transmit at, which channels they use, how many devices each one can carry, and what cabling has to reach them.
It is not a walk round with a phone app. Phone apps report signal strength as their own radio sees it, at floor level, in one direction, with no view of noise, interference, retry rates or how the network will behave when four hundred people arrive at nine o'clock. A survey uses calibrated, survey-grade equipment, a scaled plan of the building, and a surveyor who knows what the numbers mean.
New to this? The plain-English reference explains what a survey measures, what the numbers mean and what you get, with a glossary — written to be forwarded to whoever is approving the spend.
The output is a document. That matters more than it sounds — it means you can put the work out to tender on equal terms, hand it to a contractor and get a comparable price, or hold the installer to a defined standard when it goes in. Without one, you are buying an opinion.
The problems a survey solves
- Coverage that fails under load. Signal strength and capacity are different things. A site can have full bars everywhere and still fall over at shift change because the design counted square metres instead of devices.
- Dead spots nobody can explain. Usually a construction material, a mezzanine, or racking that was empty when the network went in and is full now.
- Roaming that drops sessions. Handheld scanners, voice handsets and AGVs are far less tolerant than a laptop. They need overlapping coverage designed deliberately, at the right signal levels, with the right roaming thresholds.
- Interference you can't see. Neighbouring networks, non-Wi-Fi sources, and your own access points fighting each other because everything is set to maximum power on overlapping channels.
- Quotes you can't compare. Three suppliers proposing three different access point counts, and no way to judge which is right. A survey gives everyone the same specification to price.
- Money spent on the wrong fix. More access points is the standard remedy and often the wrong one — it can make a capacity problem measurably worse.
Who it's for
Commercial organisations with a coverage or capacity problem, or a project where getting it wrong is expensive: warehouses and distribution centres, offices and fit-outs, schools and colleges, hotels and hospitality venues, care settings, managed and multi-tenant property, marinas, event venues and retail. We work UK-wide.
We do not do residential broadband support. Everything on this site is commercial work.
Which survey do you need?
Most projects use more than one. Here's the honest version — including when you don't need us on site at all.
| Your situation | The survey you need | Why |
|---|---|---|
| New building, fit-out or extension — nothing installed yet | Predictive | There is no building to measure. We model it from the drawings and the construction schedule, so the cabling and containment can be designed into the fit-out rather than chased afterwards. |
| Existing building, replacing or extending the network | On-site, usually after a predictive pass | Real walls attenuate differently to drawings, and your neighbours' networks are already using the spectrum. Measuring beats modelling once the building exists. |
| Network installed and underperforming | Troubleshooting survey | Diagnostic rather than design-led. We measure what is happening, isolate the cause, and tell you what it takes to fix it — which is sometimes configuration rather than hardware. |
| Installation just finished, or a contractor's work to sign off | Validation | Proves the installed network meets the design. This is the survey that turns a coverage promise into evidence, and the one most people skip. |
| Coverage was fine, then the business changed | On-site, scoped as a health check | More people, taller racking, a mezzanine, a new device fleet. The building changed; the design didn't. |
Not sure? Ring us and describe the building — it's a five minute conversation and it usually settles it, with no charge and no obligation. If you'd rather work through it in writing, the pre-survey questionnaire covers the same ground and gets you a fixed price.
Every survey type, explained properly
Each of these has its own page, because each one answers a different question.
Predictive survey
Modelled from your drawings before anything is bought or built.
Best for: Before the building exists, or before anything is bought
You get: AP count, positions and a budget figure
On-site survey
Measured in the building, with the walls, racking and people that are actually there.
Best for: An existing building, with the walls and racking as they really are
You get: Measured coverage, SNR and a channel plan
Validation survey
Run after installation to prove the design was delivered.
Best for: After installation, before you sign it off
You get: Measured proof against the design
Heatmapping
The coverage plots themselves — and what the colours really mean.
Best for: Any survey — this is how the results are drawn
You get: Coverage plots with the threshold stated
Ekahau surveys
The tooling the whole method runs on, and who's certified to use it.
Best for: Every survey we run, predictive and on site
You get: Calibrated measurement and spectrum analysis
The report
Exactly what lands in your inbox at the end.
Best for: Deciding whether a survey is worth commissioning
You get: A seven-part report you can tender from
What it costs
The seven things that move the price.
Best for: Budgeting, or comparing two quotations
You get: The seven things that move the price
What is a Wi-Fi survey?
The plain-English reference, if you are new to commissioning one.
Best for: Anyone commissioning a survey for the first time
You get: The vocabulary, in plain English
Pre-survey questionnaire
Ten minutes of questions and we can scope and price it properly.
Best for: Getting a fixed price without a site visit first
You get: A scoped, costed survey proposal
How a survey runs
Four stages. You get something usable at the end of each one, and you can stop after any of them.
Scope
A conversation about the building, the devices, what's failing and when. Often enough to tell you which survey you need — and occasionally enough to tell you that you don't need one.
Measure
On-site with Ekahau, predictive from drawings, or both. We capture coverage, signal-to-noise, interference, channel use, capacity and roaming behaviour.
Design & report
Access point positions and mounting detail, channel and power plan, capacity modelling, cabling and containment schedule, costed kit list with part numbers.
Install & validate
If you want us to build it, our teams do — then we survey it again and hand you the evidence that it meets the design.
What you get at the end
A survey is only worth what its report is worth. Ours is written so a facilities manager can read it, a finance director can budget from it, and an installer can build from it without ringing us for clarification.
Walk through a real report- Coverage plots per floor at the signal levels your devices need — not one generous threshold for everything
- Signal-to-noise and interference plots, so you can see what you're competing with
- Access point positions with mounting height, orientation and fixing detail
- Channel and transmit-power plan, including behaviour alongside neighbouring networks
- Capacity modelling against your real device counts and applications
- Cabling and containment schedule so the installation can be priced, not discovered
- Costed kit list with part numbers, so quotes can be compared like for like
- A written summary in plain English, for the people approving the spend
The equipment we survey with
Surveys are run on Ekahau — the toolset most of this industry designs and validates against — using calibrated survey adapters and spectrum analysis rather than a laptop's built-in radio. On-site work uses a scaled, calibrated floorplan so measurements land in the right place on the drawing. Where a building doesn't exist yet, the same platform models it from your architectural drawings and a wall-material schedule.
On the design side we are deliberately vendor-independent. We work regularly with Cisco Meraki, Ruckus CommScope, Cambium Networks, Ubiquiti UniFi and more, and we specify whatever the measured data says the building needs. If your existing platform can do the job, the report will say so.
Why choose SEGwifi
- We install what we specify. Most Wi-Fi specialists survey and hand over. We keep the containment, cabling, mounting, commissioning and validation in house — so the design doesn't get diluted by whoever ends up fitting it.
- The report is written to be used. Enough detail for an installer to work from, in language the people approving the spend can follow.
- We validate. A validation survey after installation, and a coverage guarantee with written thresholds behind it.
- Procurement-ready. CHAS, Constructionline Gold, SafeContractor and TrustMark through The Specialist Electrical Group, with RAMS, insurance and site paperwork as standard.
- Group capacity. Access to a broader range of engineers and installers when a programme needs more hands on site.
- Commercial only. No residential work, no distraction.
Common questions
Wi-Fi survey, WiFi survey, wireless site survey — are they the same thing?
Yes. Wireless site survey is the older, more formal term and the one you will see on a specification or in a tender document. Wi-Fi survey and WiFi survey are the same job described the way most people actually say it. An Ekahau survey names the toolset rather than a different service, and a WiFi heatmap survey names one of the outputs. They all describe measuring a building's radio environment so a wireless network can be designed from evidence instead of assumption.
What genuinely differs is not the name but the method: whether the survey is modelled from drawings, measured on site with a real access point, or run after installation to prove the design was delivered. Ask a supplier which of those they are quoting for — the price difference between them is large, and so is the difference in what you can build from.
Predictive or on-site — which one do I actually need?
If the building exists, on-site measurement will always beat modelling, because it captures the walls as built, the racking as loaded and the neighbouring networks as they really are. Predictive is the right answer when there is nothing to measure yet, or when you need a budget figure before committing. On most projects of any size we do a predictive design first to shape the budget, then validate and adjust it on site.
How long does a survey take?
A single-floor office is typically a day on site with the report a few days later. A large distribution centre, a multi-building estate or a site with significant outdoor coverage takes longer. Racking density and access arrangements matter more than floor area — a full warehouse takes longer to survey than an empty one twice the size. You'll have a timescale before you commit.
Do you need to shut anything down?
No. Surveying is passive measurement — we're listening, not reconfiguring. We do need physical access to the areas being surveyed, including plant rooms and anywhere at height, and we'll need to know about restricted or hazardous areas in advance. Occupied buildings, live warehouses and out-of-hours working are all routine.
What do you need from us before you arrive?
Floorplans (CAD or PDF, ideally to scale), a rough device count and what those devices do, any known problem areas, details of the existing network if there is one, and site access arrangements including any induction requirements. If you don't have drawings we can work from what you've got — it just adds time.
Will the survey tell us to replace everything?
Not unless it has to. A significant share of the sites we survey have hardware that is perfectly capable and was simply never commissioned properly — every radio at full power, overlapping channels, default roaming thresholds. Where that's the case the report says so and the fix is engineering time, not capital spend. Where the kit genuinely can't do the job, you get the measurements that prove it.
Can we use the report to get competitive quotes?
Yes, and we'd encourage it. The report is a specification: access point count and positions, kit list with part numbers, cabling schedule. Any competent installer can price from it. We think we'll win the install on merit, but the survey is yours either way.
Do you survey outdoor areas?
Yes — yards, car parks, quaysides, pontoons, campuses and open ground. Outdoor coverage has different design constraints: weatherproofing, mounting, lightning protection, power and containment to remote positions, and RF behaviour over water or across open space. It's specified separately because it costs differently.
Is this different from a network audit?
Yes. A network audit looks at switching, routing, security and configuration. A Wi-Fi survey looks at radio. They overlap — capacity problems are sometimes an uplink problem wearing a Wi-Fi costume — and where we find that, the report will say so plainly rather than selling you access points you don't need.
Let's find out what your Wi-Fi is actually doing.
Book a survey and you get measured data, a design you can build to, and a number you can budget against — not an opinion.