Engineering: what to know

What the job involves, what changes the price, and what to ask a pro.

What engineering is

Engineering applies math and science to design and evaluate systems such as buildings, utilities, drainage and mechanical or electrical equipment. Homeowners and builders hire engineers when a project needs a calculated design, an assessment of an existing system or a stamped document for a permit. This page is general information only and not professional advice for any project.

Signs you need it

  • A project needs a calculated design, such as a drainage plan, a grading plan or a heating and cooling load calculation
  • A permit or a lender asks for an engineer's stamped report or drawings
  • A system in the home or on the property is failing, and you need a cause identified before repairs
  • You are planning a change to a utility, a water supply, a septic system or an onsite stormwater system
  • A builder or contractor cannot explain the design of a system and you need an independent review

What the pro does

  • The engineer defines the problem and reviews the existing documents, drawings or equipment records
  • They visit the site to measure, test and observe the system or the building
  • They run the calculations for loads, flows, pressures, heat or electrical demand, depending on the system
  • They prepare drawings, specifications or a report that set out the design or the findings
  • They review the work of the contractors or manufacturers against the design and the code
  • They issue the stamped document or the letter the permit or the project requires

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Type of engineering needed, such as civil, mechanical, electrical or environmental, and the discipline it falls under
  • Scope, from a single assessment to a full design with drawings and specifications
  • Site visits and the testing needed to measure the system or the ground
  • Amount of existing documentation available, since missing records take longer to verify
  • Number of revisions and the reviews needed during construction
  • Permit submittal and agency review responses included in the scope
  • Timing, since a rush schedule adds work for the engineer

What a written quote should spell out

  • The exact discipline and the deliverables, such as a report, drawings, calculations or a stamp
  • Site visits and testing included, with the number of visits listed
  • Revision terms and what counts as a new scope
  • Who prepares the permit submittal and who responds to review comments
  • Construction review and the number of site visits during the build
  • Who owns the drawings and calculations, and how they may be reused

Questions to ask before you hire

  • Are you licensed to practice in this state, and can I check the license with the state licensing board?
  • Which discipline do you practice, and does it cover the system I need designed or assessed?
  • What exactly will the report or the drawings include, and will they carry your stamp?
  • What will you test or measure on site, and what do you need from me before the visit?
  • How many revisions are in the scope, and how are extra revisions handled?
  • Who should I contact for the permit submittal, and do you respond to review comments?
  • What is excluded from the scope, so I know what else I may need to hire for?

Red flags

  • They offer to stamp a design they have not prepared or reviewed
  • They do not describe the site visit or the testing they will do
  • They are not licensed to practice in the state where the work sits
  • They will not put the scope and the deliverables in writing

What you can do yourself

You can gather the existing plans, the equipment records, photos, a written history of problems and any test results, and bring them to the first meeting. Do not make engineering decisions about a system that affects safety, such as drainage, a utility connection, a load or a heating system. Ask a licensed engineer to review the design or the cause before you commit to a plan.

Licenses and permits

Engineering work is commonly licensed at the state level, and many engineering documents must be stamped by a licensed engineer to be accepted for permits. Check with your state licensing board for the engineer's license status and the stamping rules that apply to the work, and ask your local building department what they require.

Engineering questions

What is the difference between an engineer and a contractor?

An engineer designs, calculates and assesses a system and prepares documents for approval. A contractor builds or installs the work. Some projects need both, with the engineer designing and the contractor building to that design.

Do I need an engineer for a drainage problem?

Many drainage problems need a grading or drainage plan, especially when water affects a foundation, a neighbor or a septic area. Ask an engineer to confirm the cause and design the fix before a contractor digs.

How do I know which type of engineer I need?

Describe the system or the problem and the permit you need. The discipline depends on what is being designed or assessed, so ask the engineer whether their license covers the work and who should review the rest.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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