Bathroom Remodel Permit in Lake In The Hills, IL (2026)

Research by DoINeedAPermit Research Team · Updated May 2026

The Short Answer

A full bathroom remodel in Lake in the Hills requires a permit if you're relocating plumbing fixtures, adding electrical circuits, installing a new exhaust fan, converting a tub to shower, or moving any walls. Surface-only work (tile, vanity swap in place, faucet replacement) is exempt.

Lake in the Hills enforces the 2021 International Building Code through the Cook County Building Department framework, but the city has its own permitting portal and plan-review workflow that differs meaningfully from neighboring municipalities like Barrington or Inverness. Specifically, Lake in the Hills requires all bath remodels involving fixture relocation or electrical changes to route through the city's online permit system (rather than county-only filing), and the city applies a strict 42-inch frost-depth requirement for any new drain lines, which is more stringent than some downstate jurisdictions operating under 36-inch assumptions. This matters because if your remodel includes a relocated toilet or new vanity drain, the city will flag insufficient support for the trap arm during rough plumbing inspection. Plan-review timelines run 2–4 weeks for standard permits (not over-the-counter); the city also requires GFCI/AFCI schedules on electrical plans before issuance, and they will reject submittals lacking explicit shower waterproofing details (cement board type and membrane brand/thickness). Owner-builder permits are allowed for owner-occupied homes, but the homeowner must pull the permit themselves—they cannot hire a contractor to pull it on their behalf, which is a local enforcement quirk worth knowing upfront.

What happens if you skip the permit (and you needed one)

Stop-work orders in Lake in the Hills carry a $250–$500 fine plus suspension of all work until permit is pulled and re-inspected; reinspection fees are typically $150 per additional inspection.
Insurance denial: homeowner's insurance often refuses to cover unpermitted plumbing or electrical work, leaving you liable for water damage or electrical fires ($10,000–$50,000+ in damages).
Home sale disclosure requirement: Illinois Residential Real Property Disclosure Act requires sellers to disclose unpermitted work; buyers can demand price reduction or walk, costing months and thousands in negotiation.
Lender refusal: if you ever refinance or take out a home equity line, lenders will flag unpermitted bathroom work as a title defect and deny the loan ($0 available capital).

Lake in the Hills full bathroom remodel permits — the key details

The threshold for requiring a permit in Lake in the Hills is any modification that changes the bathroom's plumbing or electrical systems, alters the room's structure, or upgrades ventilation. Per IRC P2706 and the city's adoption of the 2021 IBC, relocating a toilet, sink, or shower triggers the full permit path; the same applies to any electrical work that adds a new circuit or modifies an existing circuit (including installing GFCI outlets or a new exhaust fan). The city does NOT require a permit for in-place fixture swaps—replacing a vanity with an identical-rough-opening unit, swapping a faucet, or replacing a toilet seat without moving the flange are all exempt. However, Lake in the Hills building officials have been strict about what 'in-place' means: if you're moving the vanity even 12 inches to accommodate new plumbing, you must pull a permit. The distinction matters because homeowners sometimes assume a vanity relocation is cosmetic when it's actually a plumbing modification.

Plumbing code requirements are where most Lake in the Hills rejections happen. The city enforces the 42-inch frost depth for drain lines (deeper than the 36-inch minimum in some downstate areas), meaning any relocated toilet or sink drain must be pitched and supported to that depth if it runs below the slab or into an unheated crawlspace. IRC P3005 governs trap-arm length: the horizontal section of pipe between the trap and vent cannot exceed twice the pipe diameter (so a 1.5-inch toilet trap arm cannot run more than 3 inches horizontally before the vent rises). Lake in the Hills inspectors have flagged numerous submittals where homeowners routed the drain line under the subfloor for distance without a vent, violating the code. Additionally, any shower or tub renovation requires IRC R702.4.2 waterproofing compliance: the city demands a written specification of the waterproofing assembly (e.g., 'Schluter-Kerdi with thinset and tile' or 'cement board plus Redgard membrane'), and permits will be returned without this detail. Pressure-balanced or thermostatic mixing valves are required for all tub/shower combinations (IRC P2708) to prevent scalding; single-handle cartridge valves alone do not satisfy code.

Electrical and ventilation rules in Lake in the Hills are strict and often cause delays. Every bathroom outlet within 6 feet of a sink must be GFCI-protected (IRC E3902); the city requires a dedicated electrical plan sheet showing the GFCI locations, circuit breaker assignments, and wire sizes before permit issuance. New exhaust fans must discharge to the outdoors (not into an attic), and the ductwork termination must be shown on the plan with the linear footage noted (IRC M1505 caps duct runs at 25 feet without makeup air, and the city will ask for makeup-air specification if your run is long). Many homeowners and contractors underestimate this: if your bathroom is on the second floor and the duct run to the exterior is 40 feet with three elbows, you'll need a booster fan or shorter routing, and the city will not issue without clarification. AFCI (arc-fault) protection is required on all circuits serving the bathroom (IRC E3902.16), which is a 2021 IBC addition that some older permits didn't capture—the city now enforces it uniformly.

Lake in the Hills has adopted the Cook County Building Department's online permit portal, but the city maintains its own queue and fees. Permit valuation for a full bathroom remodel typically runs $8,000–$25,000 (depending on scope, finishes, and whether plumbing is relocated); permit fees are calculated at 1.5% of valuation for the first $10,000 and 1.0% above that, plus a flat application fee of $100. A mid-range remodel ($12,000 valuation) will cost roughly $280 in permit fees plus $150–$200 for inspections. Plan-review timelines are 2–4 weeks; the city processes applications in order and does not expedite unless there is a documented public emergency. Resubmittals due to missing details (waterproofing spec, GFCI schedule, duct termination) can add 1–2 weeks. Owner-builder permits are allowed for owner-occupied properties; the homeowner must be present at all inspections and must sign the permit application themselves (no contractor signature). If you hire a licensed plumber or electrician to do the work, they cannot pull the permit on your behalf—you (the owner) must do it.

Inspections for a full bath remodel in Lake in the Hills typically occur in this sequence: (1) Rough plumbing (after framing, before drywall)—inspector checks drain lines, trap sizing, vent runs, and slope; (2) Rough electrical (same stage)—GFCI and AFCI circuits, wire sizing, outlet locations; (3) Rough waterproofing (after drywall/substrate, before tile)—inspector verifies the waterproofing membrane and cement board assembly match the approved plan; (4) Final inspection (after tile, fixtures, and trim). If your remodel does not involve framing changes, the city may skip the framing inspection. Schedule inspections at least 24 hours in advance via the online portal or by phone. Inspection failure (e.g., trap arm too long, ductwork in attic instead of exterior) requires correction and re-inspection, which is free but adds 3–5 days. Once final inspection passes, the permit is closed and you receive a certificate of occupancy (not always required for remodels, but good to have for resale documentation).

Three Lake in the Hills bathroom remodel (full) scenarios

Scenario A

In-place vanity and faucet swap, no electrical or plumbing relocation—Normandy Woods neighborhood

You're replacing your 30-year-old pedestal sink and faucet with a new 36-inch vanity and Delta faucet in the same location. The faucet hookups (hot/cold lines) are already in the wall, and you're connecting the new faucet to the same supply lines without moving them. The drain tailpiece connects to the existing P-trap under the sink—same location, same trap. The mirror and light fixture are staying. In Lake in the Hills, this is a surface-only swap and does NOT require a permit; you do not file anything with the city, and there is no inspection. However, if you move the vanity even 1 foot to the left or right (changing the drain location), or if you add an additional sink, you MUST pull a permit because the plumbing is being relocated. Cost: $0 permit fees. Timeline: none. If you're uncertain about whether the supply lines are being rerouted behind the wall, ask a licensed plumber before starting work; if they say 'we'll need to extend the hot/cold lines,' you are now relocating plumbing and need a permit ($250–$400 total, 2–4 weeks).

No permit required (fixture swap in place) | New vanity and faucet only | Existing P-trap reused | $0 permit fees | DIY or contractor, no permit tracking

Scenario B

Toilet relocation (3 feet toward the window wall) plus new exhaust fan, existing tub stays—Lakewood neighborhood

Your existing toilet is centered on the wall; you want to move it 3 feet to the right to accommodate a larger vanity. This requires a new drain line, a new vent run, and a new supply line. You're also installing a new 80-CFM exhaust fan with ducting to the soffit because the current bath has no ventilation. In Lake in the Hills, both the toilet relocation AND the exhaust fan trigger a permit requirement. The city will require a plumbing plan showing the new 3-inch toilet drain pitched at 1/4 inch per foot, the trap arm length (maximum 3 inches for 1.5-inch vent), the vent rise to the roof or soffit, and the new supply line routing. The electrical plan must show the exhaust fan circuit (typically 120V, 15A, GFCI-protected if within 6 feet of water), the GFCI outlet locations, and the duct run length to the exterior termination. Lake in the Hills will reject the permit if the ductwork termination is not explicitly shown (e.g., 'Flexible duct to soffit vent, 22 linear feet total'). Permit valuation is roughly $6,000–$8,000; permit fee is $150–$180 plus $150 for inspections (rough plumbing, rough electrical, final). Plan review takes 2–3 weeks. The toilet drain must be supported below the 42-inch frost line if routed under the slab; if your bathroom is on the first floor and the drain runs under concrete, this is critical. Rough plumbing inspection will verify trap arm length, vent slope, and drain pitch before you patch drywall. Total cost: $300–$400 in permit fees plus contractor labor ($1,500–$3,000 for plumbing and electrical). Timeline: 3–5 weeks from permit application to final inspection.

Scenario C

Full gut remodel: tub-to-shower conversion, relocated vanity and toilet, wall framing change, new electrical circuits—Deer Park North neighborhood

You're gutting the bathroom: removing the existing 5-foot tub and relocating it to a corner shower unit (new 32x32 corner shower pan). The existing toilet is moving 2 feet, and the vanity is moving 4 feet to accommodate a new half-wall that creates a pocket for storage. You're adding two new electrical circuits (one for a heated towel rack, one dedicated exhaust fan), plus GFCI outlets on the sink circuit. In Lake in the Hills, this is the most complex permit scenario, and it requires both a plumbing AND an electrical plan, plus a framing plan if the half-wall changes the room's structure. The city's most common rejection point for tub-to-shower conversions is the waterproofing assembly: you MUST submit a waterproofing schedule showing the exact product (e.g., 'Schluter-Kerdi in-line mortar on 5/8-inch cement board, all seams sealed with Kerdi-Fix'). Omitting this detail will trigger a permit return. The drain for the new shower (3-inch or 2-inch, depending on the pan), the vent stack, and the trap-arm length must all be shown. The tub supply lines (hot, cold, trim valve pressure-balanced per IRC P2708) must be rerouted to the new shower location. Any framing changes (new studs for the half-wall, blocking for the shower niche, soffit for exhaust ducting) require a framing plan showing dimensions and stud spacing. Electrical circuits must include wire size, breaker amperage, and GFCI/AFCI assignments. Permit valuation for this scope is $18,000–$28,000; permit fee is $320–$380 plus $300–$400 in inspection fees (rough framing, rough plumbing, rough electrical, waterproofing, final). Plan review typically takes 3–4 weeks due to the complexity; resubmittals are common if waterproofing or electrical details are incomplete. Lake in the Hills will not issue the permit until all three plans (plumbing, electrical, framing) are approved and signed by a professional (PE or LE optional for residential, but plan clarity is mandatory). Total cost: $600–$800 in permit fees plus $4,000–$8,000 in contractor labor (depending on trades). Timeline: 4–6 weeks from application to final inspection. Owner-builder permits are allowed, but the homeowner must coordinate all three inspections and be present; many owner-builders hire a contractor to manage permitting and inspections, which adds 5–10% to labor cost but reduces compliance risk.

Permit required (full gut, fixture relocations, wall framing, new circuits) | Tub-to-shower conversion (waterproofing assembly required) | Toilet and vanity relocated | New half-wall framing | Two new electrical circuits, GFCI/AFCI upgrades | $320–$380 permit fee | 3–4 week plan review | 5 inspections (rough framing, rough plumbing, rough electrical, waterproofing, final) | $600–$800 total permit + inspection fees

Every project is different.

Get your exact answer →

Takes 60 seconds · Personalized to your address

Waterproofing requirements for tub and shower conversions in Lake in the Hills

IRC R702.4.2 mandates a continuous waterproofing membrane in all tubs and showers, and Lake in the Hills enforces this strictly by requiring a written specification during permit review. The city will not approve a permit for a tub-to-shower conversion without knowing the exact waterproofing system: cement board type (Durock, HardieBacker, etc.), membrane (Redgard, Schluter-Kerdi, Hydroban, etc.), and installation method (thinset, mortar, sealant). A common mistake is submitting a permit without this detail and assuming the inspector will accept 'standard industry practice'—Lake in the Hills will return the permit for clarification. The city also requires that the waterproofing membrane extend 6 inches above the tub rim or 12 inches above the shower floor, and that all seams and corners are sealed (Kerdi-Fix, sealant tape, etc.).

If you're converting a tub to a shower, the waterproofing assembly must be in place BEFORE tile is installed, and Lake in the Hills schedules a separate rough waterproofing inspection (after drywall/substrate, before tile) to verify compliance. This adds an extra inspection step and timeline—plan for 5–7 days between framing and tile work for drywall, substrate, and waterproofing inspection. Pre-slope or sloped substrate (e.g., Schluter-Ramp or mortar slope) is recommended to protect the waterproofing layer, and the city's inspectors will note if the slope is insufficient (less than 1/8 inch per foot). Using a shower pan liner instead of a full waterproofing assembly (membrane under tile) is also acceptable per code, but many Lake in the Hills contractors prefer the membrane approach because it's easier to document for inspections.

Common waterproofing failures that trigger re-inspection: incomplete sealant at corners, membrane not extending above the designated height, no sealant tape at all seams, and cement board installed without being fully adhered to the substrate. If your contractor cuts corners on waterproofing, the inspector will catch it and require correction before tile is approved. Budget an extra $300–$600 for professional waterproofing (membrane, sealant, labor) beyond tile material, and schedule the waterproofing inspection at least 24 hours after the substrate is ready.

Electrical and GFCI requirements for bathroom remodels in Lake in the Hills

Lake in the Hills adopts the 2021 National Electrical Code (NEC) Article 210 for bathroom circuits, which requires GFCI protection on all receptacles within 6 feet of a sink and AFCI protection on all circuits serving the bathroom (as of the 2021 update). This is stricter than older code and causes confusion: a GFCI outlet (ground-fault circuit interrupter) protects against electrocution; AFCI (arc-fault circuit interrupter) protects against fire. The city requires that electrical plans show which outlets are GFCI-protected and which circuit(s) are AFCI-protected. Many older bathroom permits only required GFCI; now the city enforces AFCI on the branch circuit feeding the bathroom, which often means a dedicated 15A or 20A circuit breaker with AFCI capability. If you're adding a heated towel rack or new exhaust fan, those are separate circuits; if they're fed from the main bathroom circuit, the main circuit breaker must be AFCI (not just a GFCI outlet).

The city will reject electrical permits that lack a clear GFCI/AFCI schedule. Submit a one-line diagram or a simple table showing: (1) circuit number, (2) breaker amperage and type (15A standard, 20A if heavy load, AFCI if serving bathroom), (3) outlet locations, (4) GFCI or non-GFCI status. Exhaust fans do not require GFCI if the fan is not within 6 feet of the sink; however, the circuit must be AFCI-protected. If your bathroom has an outlet behind a toilet (for a night-light or future use), it still requires GFCI if it's within 6 feet of a sink or tub.

Permitting delays often occur because homeowners or contractors submit electrical plans without a GFCI/AFCI schedule, forcing the city to return the permit for resubmittal. Avoid this by submitting a single sheet that lists all outlets, their GFCI status, and circuit assignments before you apply for the permit. The city's online portal has a checklist; follow it exactly to avoid rejections. If you're uncertain about GFCI vs. AFCI, ask the electrician to submit the plan; most licensed electricians in the Lake in the Hills area are familiar with the city's requirements and can submit a compliant plan on the first try.

City of Lake in the Hills Building Department
Lake in the Hills City Hall, Lake in the Hills, IL 60156 (exact address and mailing address available on city website)
Phone: (847) 669-6100 or (847) 669-6200 (confirm with city website) | https://www.lakeinthehills.org (navigate to 'Building Permits' or 'Permits' section for online portal link)
Monday–Friday, 8:00 AM–5:00 PM (verify on city website; hours may vary seasonally)

Common questions

Do I need a permit to replace a toilet without moving it?

No. Replacing an in-place toilet with a new one (same location, same flange) does not require a permit in Lake in the Hills. You're simply removing the old fixture and installing a new one. However, if you're moving the toilet even 1–2 feet, or if you're upgrading the flange or drain line, you must pull a permit because the plumbing is being relocated.

Can I pull my own permit as a homeowner in Lake in the Hills?

Yes, if you own the home and it is your primary residence, you are allowed to pull an owner-builder permit in Lake in the Hills. You must file the permit application yourself (a contractor cannot file it on your behalf), and you must be present at all inspections. You will still need to hire licensed plumbers, electricians, and other tradespeople to do the work; owner-builder permits do not exempt you from using licensed contractors for plumbing and electrical.

How much does a bathroom remodel permit cost in Lake in the Hills?

Permit fees are calculated at 1.5% of the project valuation (the estimated cost of the work) for the first $10,000, then 1.0% above that, plus a $100 application fee. A $10,000 remodel costs roughly $250 in permit fees; a $20,000 remodel costs roughly $300–$350. Plan-review time is 2–4 weeks. Add $150–$300 for inspection fees (paid at time of permit or due before each inspection).

Do I need to submit a plumbing plan if I'm only replacing a vanity in the same location?

No. If the vanity is staying in the exact same location (same drain, same supply lines), you do not need a plumbing plan or a permit. However, if you're moving the vanity, relocating the drain, or rerouting supply lines, you must submit a plumbing plan showing the new drain routing, trap arm length, vent run, and supply line path. Lake in the Hills will reject the permit without this plan.

What is the frost depth in Lake in the Hills, and does it affect my bathroom remodel?

Lake in the Hills is in Cook County, which uses a 42-inch frost depth for drainage lines. If your bathroom remodel includes a relocated toilet or sink drain that runs under a slab or into an unheated crawlspace, the drain must be supported below the frost line to prevent settling and cracking. This typically means running the drain through a conduit or ensuring it's buried deep enough. The city's plumbing inspector will verify this during the rough plumbing inspection.

Do I need an exhaust fan in my bathroom if I'm remodeling it?

Yes. IRC M1505 requires mechanical ventilation in all bathrooms without operable windows. If your bathroom has no window, or if the existing exhaust fan is more than 10 years old, the code requires a new, properly sized fan. The city will expect the fan to be at least 50–80 CFM, depending on the bathroom size, and it must duct to the outdoors (not into the attic). A new exhaust fan requires an electrical permit.

What is waterproofing, and why does Lake in the Hills require it in writing?

Waterproofing is a moisture barrier (usually a liquid membrane or membrane sheet) installed behind tile in showers and tubs to prevent water from reaching the framing and causing rot. IRC R702.4.2 mandates it; Lake in the Hills requires you to specify the exact product (e.g., Schluter-Kerdi, Redgard, Durock cement board) during permit review so the inspector can verify it during a rough waterproofing inspection before tile is installed. Omitting this specification will cause a permit rejection.

Can I hire a contractor to pull my permit, or do I have to do it myself?

If you are the owner-builder (homeowner), you must pull the permit yourself; a contractor cannot pull it on your behalf. However, a contractor can help you prepare the plans, fill out the application, and submit it. Many contractors in Lake in the Hills offer permit-prep services. If you hire a licensed general contractor to manage the entire project (including permitting), they may pull permits under their own license (if they are licensed), but they will still need your signature on the owner-builder declaration if you are claiming owner-builder status.

How long does plan review take for a bathroom remodel permit in Lake in the Hills?

Plan review typically takes 2–4 weeks. Simple remodels (e.g., relocated vanity and fixture) may be reviewed in 10–14 days; complex remodels (tub-to-shower conversion with framing changes) can take 3–4 weeks. If the city has questions or rejects the permit for missing details (waterproofing spec, GFCI schedule, duct termination), add 1–2 weeks for resubmittal and re-review. Schedule your contractor's start date conservatively to avoid delays.

What if I start my bathroom remodel without a permit and get caught?

Lake in the Hills will issue a stop-work order, fine you $250–$500, and require you to pull a permit and undergo re-inspection before you can continue. You will also pay double permit fees (the original permit fee plus a re-pull fee). Additionally, if you plan to sell the home, you must disclose the unpermitted work on the Illinois Residential Real Property Disclosure Act (IRPDA) form, which may reduce your home's value by $5,000–$15,000 or cause a buyer to walk away.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current bathroom remodel (full) permit requirements with the City of Lake in the Hills Building Department before starting your project.

More permit guides

National guides for the most-asked homeowner permit projects. Each goes deep on code thresholds, common rejections, fees, and timeline.

Do I need a permit for a full bathroom remodel in Lake in
the Hills, Illinois?