Engineering Cost for House Plans

There's a lot of confusion about whether or not your house plan needs engineering before being approved by your building department for construction permits. In this post we'll walk you through different types of requirements, codes and engineering as well as potential costs and turn around times that you can expect.

Code Compliance:

Building code is administered at the local level. As part of your Lot Evaluation process, you should determine which building department has jurisdiction over your lot and what building code they've adopted (if any). Yes, believe it or not some remote jurisdictions have no building code!

We design all of our house plans to the latest version of the International Residential Code (IRC) which is the most commonly adopted code by local building departments across the US and many other countries. The code covers foundation design, floor construction, wall construction, roof construction, energy efficiency, and more. Some jurisdictions develop their own code or sometimes add a supplement to the IRC to account for local conditions like snow loads, earthquake risks and hurricane/wind loads.

Types of Engineering:

In the US, Engineers are licensed at the state level which makes it impractical for our family business to have engineers who have been licensed in every state on payroll. When required, Engineers will review our plans, develop overlay plans of their own and stamp those drawings to certify that they meet the required code in your jurisdiction. Note that, while we provide typical cost ranges for each service these numbers can vary widely in different jurisdictions, site conditions and house/lot sizes. We provide cost ranges as a rough reference point but you should secure multiple bids to ensure that you're getting a fair price.

Structural ($1,000-4,000 typical range):

Structural Engineering is by far the most common type of engineering for house plans (and typically what people mean when they say 'Engineering'). A Structural Engineer will design your foundation, floor framing, roof framing, load paths and window/door headers. They're put together a structural framing plan with all of this information included along with typical construction details like stepped foundations and nailing patterns.

Truss Engineering ($ = Included in Truss Bid):

We try to design our plans to use as many pre-engineered off-the-shelf trusses as possible but, in same cases, our house plans can require engineered trusses. Almost universally, this engineering is provided by the truss manufacturer so it's not something to worry too much about as an owner. When the time comes for bidding trusses, you (or your General Contractor) will simply provide the house plans to the truss manufacturer and they will developed engineered trusses for you as part of their bid. It's a highly automated computerized process.

Geotechnical ($1,000-2,000 typical range):

Geotechnical Engineering is much less common but occasionally required for sites with abnormal soil conditions. A geotechnical Engineer will go out to your site and dig test pits, test the bearing capacity and composition of the soil (before and after excavation). Their findings will be transferred to the structural engineer to be input into the foundation design. Most houses do not require Geotechnical Engineering, but if the lot is significantly sloped or has challenging soil or possible flood conditions then you might want to budget for a Geotechnical Engineer. Your Structural Engineer or local Building Department can advise.

Civil ($1,000-3,000 typical range):

Many jurisdictions require site plans but most do not require them to be stamped by an Engineer. In some rare cases, a Civil Engineer will have to be brought in to develop a site plan. The site plan will transpose the House Plan on top of the lot survey and then the Civil Engineer will layer in grading and drainage structures, hardscaping (driveways, walkways), temporary erosion control structures, utilities, landscape screening and more. They may need to perform impervious surface and drainage calculations to meet local codes.

Mechanical / Electrical / Plumbing (MEP) Engineering ($2,000-3,000 typical range):

An MEP Engineer is a type of Mechanical Engineer. MEP Engineers are very rarely needed in single-family residential projects but can be useful if you are trying to design a very complicated HVAC, electrical or plumbing system. Building Departments almost never require MEP Engineers to stamp plans so typically what happens is that each MEP subcontractor will put together a quick sketch of the system they're installing to meet the permit requirements (if needed) and Engineered plans will be overkill.

How to Find an Engineer:

So you've looked contacted your Building Department and they told you that you need your plans Engineered. There's a number of places you can look to easily and quickly get that done. As a rule of thumb, it's best to find an Engineer who is as hyper-local as possible. Not only because Engineers are licensed at the state level but because a local engineer will have knowledge about how to work effectively your Building Department and understand their requirements which reduces the risk of getting your plans rejected for resubmittal and delaying your construction process. Remember to get multiple bids!

  1. Call your building department and ask for local references.

  2. Call local contractors and ask for local references.

  3. Check out - look for experience engineers in your state with good reviews.

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