CivilGrid’s Preconstruction Planning & Civil Infrastructure Glossary

A plain-language guide to the terms used before the first shovel hits the ground.

Before any road is widened, any pipe is laid, or any fiber line is pulled, someone has to figure out what's already on the site and what's buried beneath it. That work is called preconstruction, and it comes with a language of its own.

This glossary explains that language in plain terms, for anyone who wants to understand how infrastructure gets planned, scoped, and de-risked before construction begins.

The Basics

These are the basic terms describing the preconstruction process.

Preconstruction (precon)

Preconstruction is everything that happens before construction starts: investigating the site, gathering data, defining the work, estimating cost, and identifying risks. Good preconstruction is what keeps a project on schedule and on budget once building begins.

Preconstruction data (site data)

Preconstruction data is the collected information about a site used to plan a project: what utilities run through it, what the soil is like, who owns the land, what the environmental constraints are, what permits will be required, and anything else that could be pertinent to the construction plan.

Site investigation (site assessment)

Site investigation is the process of gathering preconstruction data. It is conducted through a mix of pulling existing records, surveying the land, and physically testing what's underground.

Due diligence

Due diligence is the careful, up-front research done to understand a site's risks before committing money and time to a project.

Scoping

Scoping is the work of defining what a project will actually involve: its boundaries, the work required, the likely cost, and the risks. "Scope" is the shorthand for the agreed-upon extent of a project.

Civil engineering

Civil engineering is the engineering discipline responsible for the physical infrastructure a community relies on, including roads, bridges, water and sewer systems, drainage, and site development.

Infrastructure

Infrastructure is the set of physical systems that keep a community running: transportation, water, wastewater, power, gas, and telecommunications.

Greenfield

A greenfield is a site that has never been developed — open land with no prior construction to work around.

Brownfield

A brownfield is a site that was previously developed and may carry leftover complications, such as old foundations or environmental contamination.

Alignment

An alignment is the planned route or path of a linear project such as a pipeline, road, or fiber run. Engineers "design the alignment" before building along it.

Right-of-way (ROW)

A right-of-way (ROW) is a strip of land that a road or utility has the legal right to occupy and use, even if someone else owns the underlying property. 

Knowing What's Underground

Confirming the situation underground before you dig is often the core challenge of preconstruction. It’s also where the most expensive surprises can emerge.

Utilities

Utilities are the service networks that run to and through a site: electric power, natural gas, water, sewer/wastewater, and communications (telephone, cable, fiber optic). They can be overhead (on poles) or underground (buried).

Subsurface / underground utilities

Subsurface (or underground) utilities are utility lines buried below the surface. These are the ones you can't see and therefore the ones most likely to be damaged during digging.

Subsurface Utility Engineering (SUE)

Subsurface Utility Engineering (SUE) is a formal engineering process for finding, verifying, and documenting underground utilities, along with how reliable that information is. In the U.S., the process of SUE and the different quality levels of the data it produces follows the standard ASCE 38-22, created by the American Society of Civil Engineers (ASCE). Details on this standard and the SUE process prescribed by it can be found here.

Utility Quality Levels (QL-A through QL-D)

Utility Quality Levels are a rating system, defined by ASCE 38-22, for how trustworthy a piece of utility location data is. From least to most certain:

• QL-D: Based only on existing records. Necessary for early planning and determining where surveying should be conducted.

• QL-C: Above-ground features (manholes, valve boxes, poles) are surveyed and matched against records.

• QL-B: Geophysical tools detect a line and mark its approximate horizontal position on the surface. Also called designating.

• QL-A: The line is physically exposed and precisely measured. The highest level of certainty. Also called locating.

Different projects require different Quality Levels before resources can be committed and the construction plan can be stamped. 

As-built (record drawing, as-constructed drawing)

An as-built is a drawing that shows how something was actually built, which often differs from how it was originally designed. Regional/trade note: "as-built," "record drawing," and "as-constructed" are used interchangeably depending on the agency or country.

Potholing / daylighting / test holing

Potholing (also called daylighting or test holing, depending on the region) is the practice of digging a small, careful hole to physically expose a buried utility and confirm its exact depth, location, and condition. Which term you hear depends on the region and trade. Some crews will use "potholing" for a small, targeted hole and "daylighting" for exposing a longer run of a line, but in everyday use they're synonyms.

Vacuum excavation (non-destructive excavation, "soft dig")

Vacuum excavation is safe digging that uses pressurized water or air to loosen soil while a vacuum removes it, exposing utilities without a blade or bucket that could cut a line. It's also called non-destructive excavation or a "soft dig." Two main types:

• Hydro excavation (hydrovac) — Hydro excavation uses high-pressure water. Better in hard or frozen soil.

• Air / pneumatic excavation — Air (pneumatic) excavation uses compressed air. Leaves spoil dry and reusable.

These types of excavation remove the risk of cutting into a utility, but are more costly and time-consuming.

Ground Penetrating Radar (GPR)

Ground Penetrating Radar (GPR) is a tool that sends radar pulses into the ground and reads the reflections to detect buried objects, including non-metallic ones.

Electromagnetic (EM) locating

Electromagnetic (EM) locating is a method of detecting metallic or conductive utility lines by the electromagnetic signal they carry or can be induced to carry. It's the most common everyday locating method.

One-Call / 811 / "Call Before You Dig"

811 (also commonly known as One-Call or "Call Before You Dig", depending on your region) is the free notification service you're legally required to contact before digging. It alerts the utility owners in your area, who then mark their lines.

Locate ticket (dig ticket)

A locate ticket (or dig ticket) is the request you file with the one-call center to have utilities marked. Crews reference the "ticket" throughout the job.

APWA Uniform Color Code 

The APWA Uniform Color Code is the standardized set of paint and flag colors used to mark utilities on the ground, set by the American Public Works Association:

• Red: Electric power

• Yellow: Gas, oil, steam, petroleum

• Orange: Communications, cable, fiber optic

• Blue: Potable (drinking) water

• Green: Sewer and drain lines

• Purple: Reclaimed water and irrigation

• Pink: Temporary survey markings

• White: Proposed excavation route

Utility strike (dig-in, utility damage)

A utility strike (also called a dig-in) is when someone accidentally hits a buried line while excavating. Dig-ins can cause service outages, project delays, cost overruns, legal liability, and worst, injuries or deaths. It is a top priority of preconstruction efforts to prevent utility strikes.

Positive location

A positive location is a utility position that has been physically confirmed (QL-A), as opposed to one whose location is only estimated from records or surface signals.

Facility owner (asset owner)

A facility owner (or asset owner) is the utility company or agency that owns a given line and is responsible for its records and its marking.

Site Conditions & the Ground Itself

Beyond what humans have already put in the earth, there are many other factors of the soil and site that are relevant to how construction should be planned.

Geotechnical (geotech)

Geotechnical (geotech) work is the study of how soil and rock behave, so engineers know what they can safely build on and how deep to go.

Soil boring (borehole)

A soil boring (or borehole) is a hole drilled into the ground to pull up soil and rock samples for testing.

Geotechnical report (geotech report)

A geotechnical report (geotech report) is the document summarizing what the borings found: soil types, groundwater levels, load-bearing capacity, and recommendations for foundations and excavation.

Topography (topo survey)

Topography is the shape and elevation of the land surface; a "topo survey" is the measurement that captures it, showing the hills, slopes, and contours of a site.

Survey (land survey)

A survey (land survey) is the precise measurement of a site's boundaries, features, and elevations, performed by a licensed surveyor.

Hydrology

Hydrology is the study of how water moves across and beneath a site, including water table depths, groundwater levels, and the speed at which water flows and drains on the surface. Knowing this is important for drainage, flooding, and stormwater design.

Environmental constraints

Environmental constraints are the natural or regulatory features that limit where and how you can build, such as protected habitat, wetlands, or contamination.

Wetlands

Wetlands are water-saturated areas (marshes, swamps, bogs) that are legally protected and often can't be built on without special permits.

Floodplain / flood zone

A floodplain (or flood zone) is land at risk of flooding, frequently mapped by FEMA in the U.S. Building here triggers extra rules.

Contamination / hazardous materials

Contamination refers to pollutants in the soil or groundwater, often from prior industrial use. It's a key reason brownfield sites cost more to develop.

Land, Rights & Permissions

Another critical element of preconstruction is determining all of the legal restrictions that apply to your site.

Parcel

A parcel is a single, legally defined piece of land. It’s essentially a property lot with a boundary and an owner, which can be a public or private entity, or an individual.

Easement

An easement is a legal right to use part of someone else's land for a specific purpose, such as a utility easement that lets a power company run and maintain a line across private property.

Land rights (property rights)

Land rights (property rights) are the bundle of legal interests in a piece of land: who owns it, who can access it, and what easements exist.

Title

Title is the legal record of who owns a property and under what conditions.

Zoning

Zoning is the set of local government rules that dictate how a piece of land can be used (i.e. residential, commercial, industrial) and what can be built on it.

Encroachment

An encroachment is something that extends into land or a right-of-way where it doesn't belong. For example, a structure built over a utility easement may be encroaching on that easement.

Rules, Permits & Timing

The final piece of the preconstruction information process is working your project into existing schedules, restrictions, and opportunities presented by governing bodies.

Permitting

Permitting is the process of obtaining official approval from the relevant authorities to perform work.

Jurisdiction

A jurisdiction is the government body with legal authority over a given area (a city, county, state DOT, etc.).

Authority Having Jurisdiction (AHJ)

The Authority Having Jurisdiction (AHJ) is the specific agency or official responsible for enforcing the rules on a particular project.

Encroachment permit

An encroachment permit is permission to perform work within a public right-of-way, such as cutting into a city street.

Paving moratorium

A paving moratorium is a period — often three to five years — after a road is repaved during which agencies prohibit cutting into it. If a project cuts into it anyways, either accidentally or because of an unavoidable need, the project owner is generally required to pay to repave the entire road. Hitting a moratorium can freeze a project or force an expensive detour, so it's a critical thing to check during scoping.

Franchise utility

A franchise utility is a utility that holds a legal agreement (a franchise) allowing it to operate its lines within a jurisdiction's rights-of-way.

Stakeholder

A stakeholder is any party with an interest in the project: the affected agencies, utility owners, permit authorities, property owners, and those among the public who are affected by the construction.

Data, Maps & Design

Once you’ve collected your preconstruction data, this section covers how you make use of it to plan.

GIS (Geographic Information System)

GIS (Geographic Information System) is software for mapping and analyzing information tied to locations, organized into layers (a water layer, a gas layer, a parcel layer, and so on). CivilGrid’s own mapping tools can export into GIS.

CAD (Computer-Aided Design)

CAD (Computer-Aided Design) is the drafting software engineers use to produce designs. CAD-ready data, such as that generated by CivilGrid, can be pulled directly into CAD software without manual redrawing.

Basemap

A basemap is the foundation layer of a map showing existing site conditions, on top of which a new design is drawn.

Chain of custody

Chain of custody is a documented, unbroken trail showing where a piece of data came from and that it hasn't been altered along the way. It's what makes site data defensible: trustworthy enough to design against and to stand behind if a dispute arises.

Records research (records request)

Records research is the process of gathering existing utility and site records from the many owners and agencies that hold them; each individual ask is a records request.

Digitization

Digitization is the work of converting paper drawings and PDF records into usable digital or CAD data.

Common file formats

Common file formats in this work include DWG (AutoCAD), DGN (Bentley MicroStation), SHP (GIS shapefile), KMZ/KML (Google Earth), and PDF.

BIM (Building Information Modeling)

BIM (Building Information Modeling) is a detailed 3D digital model of a project that carries data about each component, often used on large infrastructure work.

Delivering the Project

Once your construction plan is coming together, these are terms you may encounter as execution begins.

Utility conflict

A utility conflict is when a proposed design clashes with the location of an existing utility. Catching conflicts early, and on paper, is far cheaper than discovering them in the field.

Relocation

Relocation is the work of physically moving an existing utility out of the way of new construction. It's often slow and expensive, which is why it's better identified during scoping.

Change order

A change order is a formal, mid-project change to the scope, cost, or schedule after work has started. Frequent change orders are usually a sign that preconstruction data was incomplete, and a sign that the project is liable to go over budget or behind schedule.

Rework

Rework is redoing work because of an error or newly discovered information. It's one of the largest avoidable costs in construction.

RFI (Request for Information)

An RFI (Request for Information) is a formal question raised during design or construction to clarify something unclear or missing in the plans. Having your preconstruction data verified and organized is key to responding to RFIs consistently, accurately, and quickly.

Bid / estimate

A bid (or estimate) is a contractor's proposed price to perform work in the project, built from the project's scope and known site conditions.

Capital project (capital improvement)

A capital project (capital improvement) is a major infrastructure investment to build, replace, or upgrade a long-lived asset, such as a treatment plant, a substation, or a water main.

Portfolio

A portfolio is the full set of projects an organization is planning and managing at once, rather than a single job in isolation. Understanding how priorities, costs, schedules, permits, restrictions, and other factors impact each project can create challenges across a portfolio. On the other hand, optimizing your portfolio to avoid conflict and take advantage of opportunities to bundle projects, can be a major cost and time saver.

Bundling / coordination

Bundling (or coordination) is the practice of combining nearby or overlapping projects so they're built together. This saves cost, reduces disruption, and avoids one crew tearing up a street the next crew just paved.

This glossary is maintained by CivilGrid, the civil design platform that centralizes utility, environmental, geotechnical, and land data so teams can plan and design with site information they can trust. If a term you want to learn isn’t here, reach out at info@civilgrid.com.