Fort Thomas sits on a bluff above the Ohio River, which is a lovely thing to look at and a complicated thing to build on. The housing stock is old, the lots slope, and a great deal of what holds a Northern Kentucky backyard in place was put there by somebody who is no longer available to explain it.
That is roughly the market AO Structural Engineers serves. They are a licensed structural engineering practice on South Fort Thomas Avenue, and their work is the unglamorous middle of the construction process: figuring out whether something is actually a problem, and what a repair or a new structure has to be built to.
This guide covers what the firm does, how Kentucky’s building rules are structured differently from what people on the Ohio side expect, and the point at which a backyard project stops being a weekend job and starts needing a stamp on a drawing.
Two Engineers and a Fort Thomas Practice
AO Structural Engineers was established in 2019. The name comes from its two founders, Nick Allen and Eric Oetjen, who were structural engineering colleagues before they started the firm together. Both names turn up constantly in the reviews, which tells you the principals are still the ones showing up at the house.
The practice is licensed in Kentucky, Ohio and Indiana, which matters more in this metro than almost anywhere else in the country. A firm serving Greater Cincinnati is working across three state lines within a twenty minute radius, and a license that stops at the river is not much use to a client in Fort Thomas who also owns a rental in Norwood.
Their published focus is residential and small scale commercial work. That is a deliberate niche. Most structural engineering firms want bridges, towers and industrial buildings. Comparatively few want to walk into a hundred year old house in Campbell County and give a homeowner a straight answer about a crack.
| At a Glance | AO Structural Engineers |
| Established | 2019, by Nick Allen and Eric Oetjen, who were structural engineering colleagues before forming the firm |
| What it is | A licensed structural engineering practice serving residential and small scale commercial clients |
| Licensed in | Kentucky, Ohio and Indiana |
| Address | 1220 S Ft Thomas Ave, Fort Thomas, KY 41075 |
| Phone | (859) 250-8556 |
| Hours | Monday to Friday, 8:00 a.m. to 6:00 p.m. Closed Saturday and Sunday. |
| Website | aoengineers.com |
Location, Directions and Access
AO Structural Engineers is at 1220 S Ft Thomas Ave, Fort Thomas, KY 41075. The office can be reached at (859) 250-8556, which they list for calls and texts alike.
Most of their work happens at your property rather than at their office, so the address matters less here than it does for a supply yard. It is still worth knowing where they are, and South Fort Thomas Avenue is the spine of the city, so both routes below run along it.
Coming from Tower Park
Tower Park is the center of gravity in Fort Thomas, the old Army post turned city park at 900 South Fort Thomas Avenue. From the park, continue south on South Fort Thomas Avenue. The street numbers climb from the 900s into the 1200s, and the office is in that stretch, near where Grandview Avenue meets South Fort Thomas.
Coming from U.S. 27
U.S. 27, signed locally as Alexandria Pike, meets South Fort Thomas Avenue at the southern end of the city. From that junction, head north on South Fort Thomas Avenue and the numbers fall toward the 1200s.
Access and Hours
The office keeps regular business hours, Monday to Friday from 8:00 a.m. to 6:00 p.m., and is closed Saturday and Sunday.
- The suite is upstairs, so this is a professional office rather than a walk-in storefront.
- Site visits are the normal mode of work. In most cases the engineer comes to the property rather than the other way around.
- They list a text option alongside the phone number, which is often the faster way to start a conversation about scheduling.
Scheduling is worth a call either way, since the engineers spend most of the working day out at properties rather than sitting at the office. Reach them at (859) 250-8556 to get on the calendar.
What They Actually Do
Their published services fall into a few clear buckets. Residential structural assessment is the biggest one, producing a stamped assessment report with recommendations for whatever is in question. Structural design covers wall removal, small build-outs and floor plan modifications, and they describe running an initial feasibility study before moving to construction drawings.
The design scope they publish is worth reading closely if you have an outdoor project, because it names beam sizing, foundation design, retaining wall design, and design in steel, concrete and wood.
Beyond that they handle manufactured home foundation certifications for HUD compliance, fire escape inspections, facade inspections and small commercial work.
A useful thing to understand about this kind of firm is what they are not. They are not a contractor and they do not build anything. An engineer’s product is a document: an assessment, a set of calculations, a drawing with a seal on it. That independence is the whole value. An engineer with no work to sell you has no reason to tell you that you need more of it than you do, which is exactly why several of their reviewers describe calling them for a second opinion after a contractor quoted a large repair.
Why Kentucky Works Differently
This is the part that catches people who move across the river, or who own property on both sides of it.
Kentucky operates what is known as a mini/maxi code. The Kentucky Department of Housing, Buildings and Construction adopts the Kentucky Residential Code, it applies statewide to detached single family homes, two family dwellings and townhouses, and local governments are not permitted to adopt or enforce a different building code of their own.
Enforcement, though, is local. For one and two family homes, permits, plan review and inspections happen through the city or county building department rather than the state. So the standard does not change when you cross from Fort Thomas into Newport or Bellevue, but who reviews your plans, what they want to see and how long they take absolutely can.
The practical consequence is that a homeowner should never assume a rule they read about a Cincinnati suburb applies to a Campbell County backyard, and should never assume the reverse either. Ask the office that will actually be issuing the permit.
If you are working out where a Kentucky project stands, it helps to understand what the rules look like on this side of the river before you start, and to see an outdoor project walked through from application to sign-off so the sequence is not a surprise.
Where a Backyard Project Meets an Engineer
Most decks and patios never involve an engineer, and they should not. Residential codes carry prescriptive provisions precisely so that ordinary structures on ordinary ground can be built and approved without a custom design. The question is what counts as ordinary.
On the Kentucky side of the river, a good deal of it is not. Fort Thomas, Newport, Bellevue and Dayton sit on ground that falls away toward the river, and slope changes everything. A retaining wall holding back a hillside is doing structural work in a way a wall around a flower bed is not. A deck on tall posts is a different animal from one a step down from the back door. Soil that nobody has ever tested is a variable rather than an assumption.
A few situations reliably move a backyard project into engineering territory, and none of them are exotic.
- A retaining wall above a certain height. The threshold is set locally, and it is the first question worth asking the building department.
- Anything on a slope that is holding something back. Especially where a failure would affect a neighbor’s property or a structure.
- Attaching to a house nobody has inspected. An older ledger connection is a common place for an engineer to get involved.
- Ground that has already moved. Existing settlement, cracking or leaning is a reason to understand the cause before building on top of it.
None of that means a homeowner needs an engineer by default. It means the building department decides, and the cheapest possible time to find out is before anything is designed. It is also worth knowing the mistakes that most often stop a build halfway and how the edges of a lot limit what fits in a yard, because setbacks rule out more designs than structure ever does.
Once a plan is approved, the remaining job is getting signed off without a return visit, which is mostly a matter of building what the drawings say.
Platinum Deck and Patio builds decks, paver patios and retaining walls across the Cincinnati metro including the Northern Kentucky river cities, and on sloped Kentucky lots the engineering question is worth settling early rather than discovering at plan review.
Frequently Asked Questions
Does a deck normally need an engineer in Northern Kentucky?
Usually not. Residential codes include prescriptive provisions so that standard structures can be built without a custom design. It is the unusual conditions, most often slope, height and existing movement, that change the answer, and the local building department is the authority on it.
Do they design retaining walls?
Retaining wall design is named in their published structural design scope, alongside foundation design and beam sizing.
Are they a contractor?
No. They are a licensed engineering practice. They assess, design and produce stamped reports and drawings. The building is done by someone else, which is what makes an independent opinion worth having.
Can they work on the Ohio side too?
They are licensed in Kentucky, Ohio and Indiana, and describe serving the Greater Cincinnati region across all three.
What should I have ready before I call?
Photos of whatever is concerning you, the age of the house if you know it, and a clear description of what you are trying to do. If a contractor or an inspector has already given you a written opinion, have that in front of you.
The Bottom Line
AO Structural Engineers occupies a specific and genuinely useful position in this market. Two licensed engineers who took the residential work that larger firms tend not to want, in a region where the housing is old, the ground slopes toward a river and the rules change depending on which bank you are standing on.
For a homeowner, the value is a straight answer from someone with no stake in the repair. That is worth a phone call well before it is worth a panic.
If something in your yard has moved, or a wall on a slope is part of your plan, call or text (859) 250-8556 and describe it. The conversation is short and it will tell you quickly whether you have a project or a problem.
And ask your building department first, always. They are the ones who decide, and they answer the phone for free.