South Lyon, Michigan
Looking for a South Lyon home inspector? We do certified home, commercial, mold and radon inspections in South Lyon, seven days a week. Home inspection reports come back in 24 hours.
Schedule your inspectionCall 734-331-3269
Services
For buyers, sellers, and homeowners keeping an eye on the place they already own. On new construction we also do pre-drywall inspections and 11-month builder’s warranty inspections. Our certified inspectors walk every major system in your South Lyon home and tell you plainly what they found — then put it in a photo-rich digital report within 24 hours.
Following the InterNACHI Standards of Practice:
Included free with every home buyer inspection— and none of them require us to sell your information.
SatisfactionIf you are unhappy with your inspector on the day of the inspection, before you have seen your report, tell us and we will make it right — or you owe us nothing.
30-Day WarrantyA free 30-day Guard home warranty trial, negotiated for you with no obligation. Activate it whenever you are ready.
$100 OffThe buyer’s protection guarantee: if the first home we inspect for you does not make it to the closing table, for any reason, we take $100 off any further home buyer inspection within 30 days of the original.
Optional services at an additional cost — not part of a standard inspection. Tap one to see what it covers.
A camera down the main sewer line, watching its condition from the inside — roots, breaks, bellies and blockages no visual inspection can find. More about sewer scope inspections
The wood-destroying organism report VA buyers are typically asked to provide, on the federal NPMA-33 form. Carried out during the same visit. More about Veterans WDO inspections
Up to five air samples sent to an accredited laboratory, added to the same appointment rather than booked as a second visit. More about mold inspection and testing
View a sample report
Offices, retail, multifamily and warehouses in South Lyon and across Oakland County. Know what condition a building is in before you sign — or stay ahead of problems in the one you already own. Reports in 24 to 72 hours depending on size.
Following the CCPIA commercial standards:
Commonly added to a commercial inspection at additional cost.
Commercial laterals are longer, older and carry more. A camera is the only way to see the condition of the one you are buying. More about sewer scope inspections
Air samples to an accredited laboratory, which matters most in buildings that have sat empty or had a roof or plumbing leak. More about mold inspection and testing
View a sample report
Add either to a South Lyon home or commercial inspection, or book it on its own. We test and we never remediate, so there is nothing to sell you on the back of a result — the number you get is just the number.
Radon measured in house on a professional continuous monitor; mold samples to an accredited laboratory:
The other things worth testing while somebody is already there.
Carried out after remediation on the treated area and the areas next to it, to confirm what was found. More about mold inspection and testing
A damp basement can have several causes, and the buried sewer line is the one a visual inspection cannot check. A scope rules it in or out. More about sewer scope inspections
View a sample reportSouth Lyon housing stock
South Lyon has roughly 5,226 housing units and about 56% of them are single-family detached. Homes built in a single stretch tend to wear out in the same places at the same time. That is why when somewhere was built is the first thing worth knowing about it.
The busiest stretch of building here was the 1990s: 1,796 homes, about 34% of everything standing today. It is also less detached-house territory than most of the area at 56%, so condominiums, duplexes and small multi-family buildings are a bigger share of what we inspect here — and those bring their own questions about what is yours to maintain and what belongs to the association.
The median owner-occupied home here is valued at $249,800. There are around 177 manufactured and mobile homes in South Lyon. Those are a different inspection — the questions are about the frame, the anchoring and the skirting rather than a basement.
None of this says anything about the specific house you are buying. It is the shortlist a South Lyon home inspector works through in a home of this age, and every item on it gets photographed and written up whichever way it turns out.
Housing figures: US Census Bureau, American Community Survey 2022 five-year estimates.
When South Lyon was built
88% of homes here run on utility gas. Another 59 use bottled or LP gas.
Local knowledge
The City of South Lyon opens its permit guidance with a warning that is worth more to a buyer than most of what follows it: before applying for a permit, call and verify that the job address is actually within the City limits, because the South Lyon mailing address covers the City and four surrounding townships.
That is the clearest statement of a problem this region produces constantly. A postal name is not a jurisdiction. Five different governments can sit behind one South Lyon address, each with its own ordinances, its own inspectors and its own permit records — and a permit search at the wrong one comes back empty for reasons that have nothing to do with the house.
So the first question here is not about the building. It is: which government does this address belong to? The City will tell you over the phone, and it is the cheapest call you will make on a purchase.
The housing is mostly modern. Of about 5,226 units, 1,796 were built in the 1990s and 839 in the 2000s, with 903 from the 1970s and 250 predating 1940. Around 56% is single-family detached, which leaves a substantial share in attached and multi-unit buildings.
Before you buy
Small jobs, real permits
Three items on the City’s building department page cover work most people assume needs no paperwork at all.
The first is the sump pump drain line. Since 1 September 2022 installing one requires a plumbing permit and must be inspected, and the City notes the permit may be applied for by an excavator, the same as a sewer connection or a water tap. We have not found another municipality in this project that permits the sump discharge line specifically, and it is a sensible thing to regulate — where that line goes decides whether water leaves the property or comes straight back to the footings, and a buried discharge with no recorded destination is a recurring problem everywhere.
On an inspection we follow the sump discharge as far as it can be traced and report where it appears to go. Here, unusually, there may also be a permit record telling you when the line was put in and who did it. That is worth asking for.
The second is replacement equipment. The City publishes separate residential permit applications for water heater replacement and for HVAC replacement. A swapped water heater is one of the most commonly unpermitted jobs in any housing stock, and it is also one where the details matter — combustion air, venting, relief valve discharge, and whether the installation suits the appliance that replaced the original.
The third is current enough that most buyers have not heard of it. From 1 November 2025 the City requires all A2L refrigerant to be tested in accordance with the 2021 mechanical code. A2L refrigerants are the mildly flammable replacements now entering residential cooling equipment, and they bring installation and leak-detection requirements that older systems never had. On any cooling equipment installed here from late 2025, it is a fair question whether that testing was done.
The City also requires permits for new construction, additions, sprinklers, decks, driveways and many remodeling projects, with a separate zoning compliance application covering fences, sheds under 200 square feet, patios, driveways and sidewalks. And it offers sound advice we would repeat: if the property is in a homeowners association, check the association’s requirements before making exterior changes, because a City permit says nothing about those.
Water
South Lyon runs the whole stack, which is unusual for a city this size: its own water system, its own sanitary and storm sewers, its own water plant and its own wastewater treatment facility.
The water department describes a supply drawn from three wells between 120 and 125 feet deep, with a 2002 plant renovation that added iron filtration and pumping capacity, a million-gallon ground storage tank and a 500,000-gallon elevated tower holding City pressure at 60 to 70 psi. The wastewater plant is designed to treat 1.5 million gallons a day and discharges to Yerkes Drain, which flows west to the Huron River.
The wellhead protection page contains the detail that sticks: the City’s aquifer lies beneath the Pumpkinfest parade route, it supplies 3,300 homes and businesses at about two million gallons a day, and a single drop of motor oil can contaminate hundreds of gallons of water. A city drawing its drinking water from directly under itself has a reason to care about what goes into the ground.
On lead: the City is redeveloping its water service line inventory and confirming the locations of any lead service lines, as the Michigan Lead and Copper Rule requires, and has retained a consulting engineering firm to help. Selected residents receive a postcard asking them to take part. If you are buying here, the City’s inventory is the authoritative answer about a specific address — not a build year, and not us.
We do not test water. That is a separate discipline with its own certified laboratories, and the City publishes its annual drinking water quality report and its PFAS results. What an inspection contributes is a report of the visible supply piping where it is accessible — what it appears to be where the service enters the building and along exposed runs — which narrows the question without settling it.
The City also publishes a cross connection control plan, a brochure and a backflow assembly test form. The domestic end of that is hose bibbs without vacuum breakers, irrigation connections, boiler fills and softener drains without an air gap, all of which we look at.
Practicalities
A few operational details are worth knowing if you are buying, selling or renovating here.
Inspections require 24 hours notice and are available Monday through Thursday only. The building department’s counter hours are 9am to 2pm. The City does not accept online submissions, and card payments carry a surcharge. None of that is unusual for a city this size, but it does mean a compressed closing timetable needs planning rather than optimism.
On the utility side, bills run quarterly in January, April, July and October, covering water, sewer and garbage together. If you are moving, the City asks for a week’s notice to schedule a final meter reading. That is worth doing properly — a final reading is what separates your account from the next owner’s, and it is far easier to arrange before the move than to unpick afterwards.
The City code of ordinances is the place for the rest.
What a buyer’s inspection adds to all of this is the condition of the building itself: the roof, structure, foundation, drainage, electrical, heating and cooling, plumbing and the accessible interior, reported to you with photographs. On a housing stock that is largely 1990s, the recurring theme is first-generation components reaching the end of a normal service life at roughly the same time — the original roof covering, the original furnace, the original water heater and the original air conditioning, all bought in the same year and all wearing out in the same few.
The buried line
The City owns and operates the sanitary sewer here, but the lateral running from a building to the main is still the one component no visual inspection reaches.
On a 1990s house — the largest slice of this city at 1,796 units — that pipe has been in the ground about thirty years, with the landscaping planted alongside it now fully mature and rooted. On a 1970s house it is fifty. Either is long enough for roots to find a joint, for ground movement to displace a section, or for a repair to have been made that nobody now remembers. We will not name a material from a build year, because no authoritative source establishes what South Lyon laterals are generally made of.
People sometimes assume a newer house is exempt from this. Thirty years of mature landscaping over a pipe is not a short time, and a 1990s subdivision is exactly where the trees planted at construction have now reached the size where their roots are looking for water.
A sewer camera inspection records what is actually inside the line: roots, cracks, displaced joints, bellies or blockages where they exist, and a clear run where they do not. It is added to the same visit rather than booked separately. Alongside it, commercial building inspections follow the CCPIA standard for offices, retail, multifamily and warehouse property, and radon testing or mold inspection and testing can be added to a residential or commercial visit. Get in touch to talk through a particular property.
Local information from City of South Lyon — Building Department, permits and inspection practice · City of South Lyon — Water Department, wellhead protection and service line verification · City of South Lyon — code of ordinances. Municipal requirements change — verify current details with the municipality.
Radon in Oakland County
Zone 2 is the middle EPA category — the predicted average indoor level across the county sits between 2 and 4 pCi/L. What a zone cannot tell you is anything about one house: 29% of tests actually run in Oakland County still came back at or above the EPA’s 4 pCi/L action level. A zone is an average taken across a whole county, and no house is an average.
We place a continuous monitor for 48 hours and read the result on site — no mail-in kit, no lab wait. How radon testing works · Oakland County radon and inspection coverage
Zone from the EPA Map of Radon Zones. Elevated-result share from the Michigan Indoor Radon Program.
Why choose us
Five reasons people here pick us as their South Lyon home inspector.
Family owned since 2009, more than 16,000 inspections completed and over 2,000 five-star reviews across Michigan. We also handle home buyer inspections, commercial building inspections, mold testing and radon testing.
We do not sell mold remediation or radon mitigation, so there is nothing to gain from a result that comes back bad. The number you get is just the number.
Radon, mold, sewer scope and wood-destroying organism inspections go on the same appointment as the home inspection rather than costing you a second morning.
Most people do, and it is the most useful hour of the whole purchase. Ask anything while we are standing in front of it.
InterNACHI and CCPIA certified, with four Certified Master Inspectors and National Home Inspector Examination passes on the team — none of which Michigan requires. The standards we inspect to are published and you can hold the work against them.
Including weekends, because inspection windows sit on closing dates and closing dates do not care what day it is.
Reviews
I recently hired Trademark for a full home inspection on a new purchase, including sewer scope and radon testing. It was a phenomenal experience from beginning to end. Our inspector, Mitch, did a fantastic job explaining all the findings, and the digital report with photos and videos was superb. Would definitely recommend without hesitation.
Salina HamiltonOak Park, MIWe had Mitch inspect our prospective house and he was amazing. He was thorough, patient to answer my questions and provide feedback on what areas he would recommend having a follow up expert and why. The office was responsive and I was able to book multiple services to be done in the same visit (inspection, radon test, sewer scope).
Chris PlaweckiOak Park, MIExcellent sums up the entire experience, from the initial call to set up the appointment with staff that was informative and helpful, up until the actual inspection that was very professional and thorough with any and all questions I had answered. I would highly recommend Trademark to anyone who needs inspection services. Thanks again Curt, my inspector, for an excellent job.
Johnny Thomas JrSouthfield, MIWhat happens
Questions
Quite possibly not, and the City says so itself. Its building department advises calling to verify that a job address is within the City limits, because the South Lyon mailing address covers the City and four surrounding townships. Five governments can sit behind one postal name, each with its own ordinances and its own permit records, so confirm before relying on anything you have read or searched.
Yes. Since 1 September 2022 the City has required a plumbing permit for installing a sump pump drain line, and the line must be inspected. The permit may be applied for by an excavator, the same as a sewer connection or water tap. That is unusual — most municipalities do not permit the discharge line — and it means there may be a record of when the line went in and who installed it.
The City publishes separate residential permit applications for water heater replacement and for HVAC replacement, so both are permitted work. A swapped water heater is one of the most commonly unpermitted jobs anywhere, and one where the details matter — combustion air, venting, and relief valve discharge among them.
From 1 November 2025 the City requires all A2L refrigerant to be tested in accordance with the 2021 mechanical code. A2L refrigerants are the mildly flammable replacements now coming into residential cooling equipment, and they carry installation and leak-detection requirements older systems never had. On cooling equipment installed here from late 2025, it is fair to ask whether that testing was carried out.
From three City wells between 120 and 125 feet deep, treated at the City’s own plant and held in a million-gallon ground tank and a 500,000-gallon elevated tower at 60 to 70 psi. The City also runs its own sanitary and storm sewers and its own wastewater plant, which discharges to Yerkes Drain and on to the Huron River. The aquifer lies beneath the City itself, which is why wellhead protection gets the attention it does here.
The City is redeveloping its water service line inventory and confirming the locations of any lead service lines, as the Michigan Lead and Copper Rule requires, with a consulting engineering firm assisting. Selected residents receive a postcard asking them to take part. The City’s inventory is the authoritative answer for a specific address. We do not test water — that is a separate discipline with its own certified laboratories.
Mostly modern. Of about 5,226 housing units, 1,796 were built in the 1990s and 839 in the 2000s, with 903 from the 1970s, 656 from the 1980s and 250 predating 1940. Around 56% is single-family detached. On a 1990s house the recurring theme is first-generation components — roof, furnace, water heater, air conditioning — all bought in the same year and wearing out within a few years of each other.
Yes, and the newness of much of the stock is not a reason to skip it. On a 1990s house the lateral has been in the ground about thirty years, with subdivision landscaping now mature and rooting. We will not guess a material from a build year. Putting a camera down the line documents roots, cracks, displaced joints, bellies or blockages where they exist, and is added to the same appointment.
More on cost, timing and what is included on the FAQ page.
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Permits, assessing and property records for South Lyon are handled by South Lyon, Michigan, not by us.
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Your local South Lyon home inspector, seven days a week. Home inspection reports in 24 hours.
