Troy particulars
Only 11.7 percent of Troy's housing units predate 1960, though 60.5 percent predate 1980, among about 34,997 homes with a median value of $396,800. The Building Department is at 500 W. Big Beaver Rd, 248-524-3300, open 8 a.m. to 4:30 p.m. Its codes page says the 2015 Michigan Residential Code remains in effect after LARA agreed to pause the 2021 version, which settles which edition your contractor should be building to.
Troy's residential permit requirements talk about plot plans, grade slips and plans that include the foundation. Nothing we can cite addresses repairing a foundation or waterproofing one, and we have no Troy fee figure, so ask the department. A USGS atlas says former glacial lake beds appear as flat, clay-rich sediments in southeastern Oakland County, and EPA's ecoregion map puts Troy's center on the clayey Maumee Lake Plain; both are county-scale or regional readings, and we place Troy in that corner ourselves. Troy sits in Oakland County, EPA radon Zone 2. Clawson is 3.3 miles away and Birmingham 4.5.
Crawl space encapsulation in Troy: what to know
Section R408.3 allows an unvented crawl space with a continuous Class I vapor retarder, joints overlapped 6 inches and sealed, plus exhaust or conditioned supply at 1 cfm per 50 square feet. No dehumidifier or mil thickness appears in that section, so treat a claim to the contrary as a sales line.
In Troy, 11.8 percent of homes were built in 2000 or later and 60.5 percent before 1980. The Building Department's phone is 248-524-3300 for permit questions. Oakland County is in EPA radon Zone 2, 2 to 4 pCi/L predicted; test before and after any sealing work, and read our radon guide. Ask the bidder for the license number and look it up at michigan.gov/statelicensesearch.
Permits for crawl space encapsulation in Troy
Nothing we found lists encapsulation as a permit item.
Many cities run their own building department, so start by asking the City of Troy building department who issues foundation repair permits.
When a damp crawl space counts as an emergency
- Water is standing in the crawl space near wiring or a furnace. Do not wade in.
- The floor above is sagging or a support has moved.
- A musty smell in summer.
- Condensation on cool pipes or the rim joist.
What to check before you call about a crawl space
Try this first: ask the bidder how the plan handles air exchange once vents are closed.
- Look at the ground and the floor above with a flashlight, and note standing water, wet insulation or a smell.
- Buy a humidity meter and read it over a few weeks.
- Ask any company to say in writing what it measured.
What crawl space encapsulation costs
The estimate below is the Michigan-wide one, adjusted for Michigan wages and not for Troy in particular. The same table is on the crawl space encapsulation page. How we estimate costs. Prices as of Oct 19, 2026.
| Item | Figure | What it is |
|---|---|---|
| Estimated range, not a quote | $2,300 to $15,300 per project | Built from 2 national published ranges, adjusted by the Michigan carpenter median wage ratio (1.02). No Michigan foundation company price is shown, because none of the companies we looked at published a price we could count. |
| Estimated range per square foot, not a quote | $3 to $12 per square foot of crawl space | Built from one national published range, adjusted by the Michigan carpenter median wage ratio (1.02). No Michigan foundation company price is shown, because none of the companies we looked at published a price we could count. |
| Carpenters, Michigan median | $61,680 a year | What workers are paid (BLS 2025 data via O*NET), not what you are charged. |
| Construction laborers, Michigan median | $49,590 a year | What workers are paid (BLS 2025 data via O*NET), not what you are charged. |
| Building permit, Sterling Heights | $56 application fee | 2026-27 application. No encapsulation line. |
| Building permit, Grand Rapids | $79 for work valued at $1 to $1,000; $215 at $20,001 to $21,000 | FY2027 chart. No crawl space line. |
| Building permit, Lansing | $175 for work valued at $4,001 to $10,000 | Schedule of July 1, 2026. |
How we estimate costs: the Estimated range row is a model, not a quote. It takes two published national ranges for this job (cost guides from third-party sites that we have not verified and do not cite) and multiplies them by Michigan's carpenter median wage ratio to the US (1.02, BLS 2025 data read through O*NET OnLine). No permit fee is added: the city permit rows below are shown as printed. The wage and permit rows are what workers are paid and what a city's own schedule charges, and neither is a price. Your soil, water and the repair method move a real quote well outside any range, so get an independent diagnosis first. We have not collected quotes, and we found no Michigan foundation company that publishes a price we could count. Full method.
Questions about crawl space encapsulation
Do crawl spaces need encapsulation?
Not under the base code text cited here. The 2015 residential code allows a vented crawl space, and allows an unvented one built to R408.3, so encapsulation is a choice and not a requirement.
Is a dehumidifier required in an encapsulated crawl space?
The 2015 code section cited here does not name one. It requires continuous exhaust or conditioned air at 1 cfm per 50 square feet, and does not name a liner thickness either.
What humidity should an encapsulated crawl space be?
No government agency source cited here sets a target for a crawl space. EPA's figure of below 60 percent, ideally 30 to 50 percent, is for indoor air, and a humidity meter costs about $10 to $50.