What a Site Survey Establishes
Six Facts Decide the Design
A survey is not a look around. It is the collection of a small set of facts, each of which can rule a design in or out on its own. Fall across the opening, setback from the road, clear run along the boundary, the route for power, what is buried, and how vehicles actually approach. A quote produced without them is a price for a gate rather than for this entrance.
Fall Across the Opening
The difference in level between the two posts, and the slope of the ground the leaf travels over, decide whether a swing gate is workable and how much ground clearance it needs. Where the driveway rises away from the road, the arc of an inward swinging leaf is the constraint. Measuring this properly, rather than judging it by eye, is the difference between a gate that opens fully and one that stops at forty degrees.
Setback and What Waits There
The distance from the gate to the road determines whether a vehicle can stand clear while the gate cycles. Where that distance is short, the design has to favour speed, which pushes toward a slide gate or a faster operator, and it changes the safety provisions because a reversing vehicle in a traffic lane is a different risk profile.
What Is Buried
Footings for a gate are deep, and they land exactly where services often run: the water line to the house, an irrigation main, a gas service, or a buried electrical feed. Locating before digging is not optional, and it occasionally moves a post by a foot, which in turn changes the opening width and therefore the gate. This is the single most common reason a design changes after quoting.
Power and Its Route
Automation needs a supply at the gate. Where the trench for that supply runs, how long it is, and whether it crosses paving or a driveway all carry real cost, occasionally more than the operator itself. It is also where a solar option becomes worth pricing, because a long trench across finished surfaces changes the arithmetic.
How Vehicles Actually Arrive
Watching a vehicle turn into the entrance shows the swept path, which is wider than the vehicle wherever the approach is not square on. The largest vehicle that will realistically use the entrance, including anything towed, sets the clear width. This is the measurement most often taken from the daily driver and most often regretted.
Get It in Writing
The survey findings should appear in the quote, because they are the assumptions the price rests on. When a contractor writes down the fall, the clear run and the trench length, both sides know what was priced and what happens if the ground says otherwise.