Predictive vs On-Site Survey: Which Do You Need?

By Titan Grid · Published 13 September 2026 · Updated 20 September 2026

Short answer: a predictive survey models your wireless network on paper before anything is installed, while an on-site survey measures the real environment. They answer different questions, and confusing them is one of the most common mistakes when planning a wireless deployment.

Predictive vs on-site at a glance

	Predictive survey	On-site survey
What it is	A software model of your building and its wireless coverage	Measurements taken on site, in the real environment
Best for	New builds, fit-outs, budgeting and pre-purchase design	Existing buildings, troubleshooting and post-install validation
Needs	Floor plans and building material details	Site access and up-to-date floor plans
Typical timeframe	2-3 business days after receiving floor plans	1-3 days on site, depending on size and complexity
Main limitation	Only as accurate as the plans and assumptions it is built on	Reflects conditions on the day of the survey
Output	Coverage and capacity heat maps, AP placement, bill of materials	Real-world heat maps, interference analysis, remediation plan

Predictive survey

A predictive survey uses building floor plans and material properties to model wireless coverage before any equipment is installed. It's ideal for new builds and budget planning, since it lets you finalise an access point layout and a budgetary bill of materials before construction or fit-out is complete. Because it is a model, its accuracy depends on the quality of the floor plans and the material assumptions used.

On-site survey

An on-site (active and passive) survey measures real-world conditions using professional tools like Ekahau. It's essential for existing buildings, where wall materials, interference sources and neighbouring networks all affect performance in ways a floor plan alone can't predict.

Which one should you book?

New building or fit-out: start with a predictive survey, then validate on site once access points are installed.
Existing building with complaints: an on-site survey will show exactly where and why performance drops.
Critical environments such as hospitals, warehouses, venues and multi-floor campuses: we recommend both — predictive for design, on-site for validation.

Learn more about our predictive WiFi design and on-site WiFi survey services, or see what a WiFi site survey is if you are just getting started.