Ann Arbor particulars
Washtenaw County is one of the nine Michigan counties in EPA's highest radon zone, Zone 1, where the predicted average indoor level is above 4 pCi/L. EGLE says the residential code requires radon-resistant construction in new homes there, but that rule does not reach an existing house, so testing is still on you. Ann Arbor's fee schedule, revised July 15, 2025, treats basement waterproofing as a building permit that also requires grading plan review and a grading permit, with a $15 base application fee and a permit fee of $100 plus $10 per $1,000 of project cost.
Applications go through STREAM; the office is at 301 E. Huron St., 734-794-6263. The city's flooding page says basement water can come from storms, spring snowmelt or groundwater building up, and advises a backup for the sump pump. Of 53,715 housing units, 64.3 percent predate 1980, 30.5 percent predate 1960 and 15.2 percent predate 1940, and the median value is $435,100, high enough that an engineer's report is small next to the bill. Ypsilanti is 6.0 miles away.
Basement waterproofing in Ann Arbor: what to know
The fee sheet revised 7/15/2025 says basement waterproofing is the same as a building permit and requires Grading Plan Review and a Grading Permit based on estimated cost. By that formula an $8,000 job is $15 plus $100 plus $80, or $195 before plan examination, which is our arithmetic from the printed rates. Check the current sheet because its header still reads October 2019.
The city says basement flooding can come from heavy storms, spring snowmelt or excess groundwater entering through leaks or seepage, that poor yard drainage adds risk, and that homeowner insurance often excludes it. It also advises a sump pump backup and testing the system at least twice a year. Our permits by city guide compares this with other cities.
Permits for basement waterproofing in Ann Arbor
Five of the ten cities in this set name waterproofing as a permit item, and the rest print no line, so ask your city.
Many cities run their own building department, so start by asking the City of Ann Arbor building department who issues foundation repair permits.
When a wet basement is an emergency
- Water is rising near the electrical panel, outlets or furnace. Stay out of the water.
- A wall is bowing or has cracked inward while wet.
- Damp patches or a musty smell in dry weather.
- A seep after heavy rain that drains away on its own.
What to check before you call about a wet basement
Try this first: ask the contractor who will file the grading permit, and get its number before work starts.
- Run a humidity check and watch whether the damp shows on dry days; condensation looks like a leak in summer.
- Make sure downspouts end beyond the wall and the soil slopes away from it.
- Ask each company where the water enters and what it would try first.
What basement waterproofing costs
The estimate below is the Michigan-wide one, adjusted for Michigan wages and not for Ann Arbor in particular. The same table is on the basement waterproofing page. How we estimate costs. Prices as of Oct 19, 2026.
| Item | Figure | What it is |
|---|---|---|
| Estimated range, not a quote | $4,375 to $13,500 per project | Built from 2 national published ranges, adjusted by the Michigan construction laborer median wage ratio (1.05). 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 | $4 to $12 per square foot, interior system | Built from one national published range, adjusted by the Michigan construction laborer median wage ratio (1.05). No Michigan foundation company price is shown, because none of the companies we looked at published a price we could count. |
| Construction laborers, Michigan median | $49,590 a year | What workers are paid (BLS 2025 data via O*NET), not what you are charged. |
| Cement masons and concrete finishers, Michigan median | $59,860 a year | What workers are paid (BLS 2025 data via O*NET), not what you are charged. |
| Building permit, Ann Arbor | $15 application fee, then $100 plus $10 per $1,000 of project cost | Waterproofing is priced the same as a building permit, plus grading review. |
| Renovation permit, Dearborn | $100 plus $15 per $1,000 above $2,000, with a $100 processing fee | Plan review of $1 per $1,000 includes waterproofing. |
| Waterproofing application, Livonia | $45 administrative fee | Building permit and plan review fees are based on cost; we did not find the schedule. |
| Plumbing permit, Sterling Heights | $55 for basement waterproofing, plus a $55 application fee | 2026-27 plumbing chart. |
| Plumbing permit, Warren | $80 for basement waterproofing, $80 minimum | 2025 application. Warren's building fee sheet is dated 2014. |
| Plumbing permit, Westland | $50 for interior perimeter subsoil drainage and sump pit, plus $100 administration fee | Revised July 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 construction laborer median wage ratio to the US (1.05, 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 basement waterproofing
What is a waterproofed basement?
One where below-grade walls are treated to resist liquid water, not only dampness. The 2015 residential code calls for dampproofing in ordinary conditions and waterproofing where a high water table or severe soil-water conditions are known to exist.
How much does basement waterproofing cost in Michigan?
Our estimate for basement waterproofing in Michigan is $4,375 to $13,500 per project, or $4 to $12 per square foot, interior system. It is modeled from national published ranges, because we have collected no Michigan quotes. The University of Minnesota Extension ranks exterior drainage as the most costly and most effective option and gives no dollars. Ask for an itemized written price.
Does waterproofing a basement need a permit in Michigan?
In five of the ten cities in this set, yes, it is a named item: Ann Arbor, Dearborn, Livonia, Sterling Heights and Warren. Westland lists interior drains under plumbing. Ask your own building office.