Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Like-for-like window replacement in the same opening size is exempt from permitting in Round Lake Beach. However, if your home is in the historic district, if you're enlarging the opening, or if you're replacing an egress window in a basement bedroom, you will need a permit.
Round Lake Beach follows Illinois Building Code, which exempts like-for-like window replacement (same opening size, same operable type) from permit requirements. What sets Round Lake Beach apart from neighboring communities is its strict historic-district overlay: if your property falls within the designated historic district (primarily older homes near the lakefront and downtown), the City's Historic Preservation Commission must approve your window design BEFORE you file any permit or purchase materials — this is a design-review step that adds 2-4 weeks and is separate from building permitting. Additionally, Round Lake Beach enforces the current IECC energy code, which means replacement windows must meet the U-factor requirements for Climate Zone 5A (0.32 U-factor for most double-hung windows). If you're replacing an egress window serving a bedroom (even at the same opening size), sill height must not exceed 44 inches from the floor per IRC R310 — this triggers a permit and final inspection. The City Building Department does accept owner-builder applications for owner-occupied homes, and they process simple replacements over-the-counter with no re-submission delays.

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

Round Lake Beach window replacement — the key details

Round Lake Beach operates under the 2021 Illinois Building Code (IBC) and 2021 IECC energy code, which exempts like-for-like window replacement from permits — meaning same opening size, same number of operable sashes (e.g., double-hung stays double-hung), and no change to sill height or egress compliance. The exemption is stated in the Illinois Building Code Section R612.2 (window fall protection) and IBC Section R612.3 (same-size replacement exclusion). However, the City Building Department applies a critical caveat: if the existing window does not currently meet IECC U-factor requirements (0.32 for north Illinois, 5A climate), and your replacement window is being installed as an energy upgrade, it triggers a permit and plan review to confirm code compliance. Many homeowners overlook this because they assume 'replacement' means automatic exemption — it doesn't. The rule exists to ensure energy-code drift doesn't accumulate over decades of replacements. If you're in doubt, call the City Building Department (see contact card below) with your home's address and window type; they'll tell you if plan review is required in 5 minutes.

Round Lake Beach's historic-district rules are the single biggest trigger for window-replacement permits in the city. The historic district includes approximately 20 blocks of early-1900s homes near Round Lake Avenue, the old downtown, and portions of lakefront property. If your address falls within this zone (check the city's zoning map online or call the Planning Department), you must submit a Design Review Application to the Historic Preservation Commission BEFORE you purchase or install any window. This review focuses on profile (depth of muntins, frame color, material — typically wood or wood-clad aluminum that matches the original), not energy code. Once the HPC approves your design, you then file the building permit if required by opening size or egress status. Non-historic homes outside the overlay do not undergo this second step. The HPC process typically takes 4-6 weeks (one commission meeting cycle plus staff review). Many contractors are unaware of this requirement and inadvertently order windows that the HPC later rejects, costing the homeowner thousands in delays and remake orders.

Egress windows in bedrooms are a frequent surprise. IRC R310.1 requires bedrooms to have an emergency escape window (egress window) with a sill height not exceeding 44 inches from the floor. If you're replacing an existing egress window — even at the same opening size — the replacement must maintain sill height at or below 44 inches. If the existing window's sill is above 44 inches (common in older homes), a simple replacement is not permitted; you must either lower the sill (which requires header adjustment and a full structural permit) or the room loses its egress-compliant status, which can affect resale value and code violation notices. Round Lake Beach's Building Department will flag this during any permit review and will not approve a same-size replacement if sill height is non-compliant. The workaround is to file a full-scope window replacement permit showing the new sill height; this triggers framing inspection and costs $200–$400 in permits plus contractor labor for header reframing. Many homeowners discover this issue mid-replacement when the new window frame doesn't fit the old opening, leading to costly re-work.

Tempered glass is mandatory within 24 inches of doors and within 60 inches of bathtub/shower enclosures per IBC R612.3. If your home has a window within these zones, replacement windows must be tempered safety glass — this is not an exemption trigger, but it is a specification that must be correct on the window order. Round Lake Beach inspectors do verify tempered status at final inspection (either by label or by visual inspection). Failure to specify tempered glass results in a failed inspection and forced replacement at your cost. Additionally, the City enforces the current IECC U-factor requirement (0.32 maximum for 5A climate zone), which means your replacement window must have a certified U-factor meeting or beating this threshold. Standard single-pane replacement windows do not meet this — you typically need a double-pane or triple-pane unit. If you're replacing old single-pane windows with new single-pane units (sometimes done for historic accuracy), you may face a code-compliance objection, especially if the Building Department classifies the project as an 'energy upgrade' rather than a like-for-like replacement. Check the window's NFRC label before purchase to confirm U-factor compliance.

Timeline and inspections: Like-for-like replacements outside the historic district require no permit and no inspection — you simply order, install, and you're done. If a permit is required (egress, opening enlargement, historic district, or energy-code upgrade), expect 1-2 weeks for plan review (if submitted over-the-counter; 3-4 weeks if submitted by mail) and a final inspection scheduling 3-5 business days after you notify the Building Department that work is complete. Round Lake Beach does not require pre-installation inspections for window replacement — only final. Owner-builders are permitted to pull permits for owner-occupied homes; you'll need a valid ID and proof of ownership. Contractor licenses are required if the work is done by a third party. Once the permit is issued, you have 180 days to complete the work before the permit expires. The Building Department can be reached at the City of Round Lake Beach main number; ask for the Building Division. They maintain an online permit portal (address below) where you can check permit status.

Three Round Lake Beach window replacement (same size opening) scenarios

Scenario A
Same-size double-hung replacement, non-historic home, basement bedroom with existing egress window — sill height 40 inches
You have a 1960s home in Round Lake Beach (non-historic district). Your basement bedroom has a double-hung window serving as an egress window; the sill is 40 inches from the floor. You want to replace it with a new, energy-efficient double-hung window in the same opening size. Since the existing sill height (40 inches) is already code-compliant (below the 44-inch limit per IRC R310.1), a like-for-like replacement of the same opening does not require a permit under Illinois Building Code Section R612.3. You simply purchase a replacement double-hung window matching the original opening dimensions (for example, a standard 24x36 or 28x40 size), install it, and seal it. No permit, no inspection. However, you should verify the new window's NFRC label confirms it meets the IECC 0.32 U-factor requirement for Climate Zone 5A (most modern double-pane windows do). The installation is straightforward: remove the old sash and frame, insert the new pre-assembled frame unit into the opening, shim level and plumb, seal with caulk and trim. Cost for materials is typically $400–$800 per window; DIY installation saves contractor labor ($200–$400 per window). Timeline: 1-2 hours per window for an experienced DIYer, or a day for a contractor doing 3-4 windows in one trip. No inspections required.
No permit required (same opening size, sill ≤44 inches) | NFRC U-factor ≥0.32 required | Double-pane insulated unit | Materials $400–$800 per window | DIY or contractor labor $0–$400 | Total project $400–$1,200 per window | No permit fees
Scenario B
Historic-district window replacement, same opening size, 1890s Victorian near downtown — wood double-hung to be replaced
Your home is a 1920s Colonial Revival in Round Lake Beach's historic district (dowtown/lakefront area). You have original wood double-hung windows with rope-and-pulley sashes, rope deterioration, and you want to replace them with modern insulated double-hung units. Even though the opening size is identical and the sash count is the same (double-hung stays double-hung), a permit is REQUIRED because your property is within the historic-preservation overlay. First step: submit a Design Review Application to the Historic Preservation Commission. You must provide window profiles, materials (the HPC will likely require wood or wood-clad aluminum to match the original), color (typically off-white or historical paint color match), and frame depth. The HPC will compare your design against the Secretary of Interior Standards for historic windows. This review takes 4-6 weeks (approximately one HPC commission meeting cycle). Once approved, you then file the building permit with the HPC approval letter. The permit itself is $150–$250 (not based on valuation for a simple replacement, but by window count — typically $50–$75 per window). Plan review is minimal (1 week) because the HPC has already vetted the design. Final inspection occurs after installation to verify the window matches the approved design. Timeline: 6-8 weeks total (4-6 weeks HPC review, 1-2 weeks permit processing, 1 week post-installation inspection scheduling). Materials cost depends on window quality; wood double-hung windows from quality manufacturers (Marvin, Pella, Andersen) run $800–$1,500 per window. Contractor labor for removal and installation is $300–$600 per window. Total per window: $1,100–$2,100. This is significantly higher than a non-historic replacement, but necessary to preserve the district's architectural integrity.
Historic-district design review required (4–6 weeks) | HPC approval needed before permit | Building permit $150–$250 total | Wood or wood-clad aluminum frames required | Match original profile and color | Window cost $800–$1,500 each | Labor $300–$600 each | Total $1,100–$2,100 per window | Final inspection mandatory
Scenario C
Opening enlargement (from 24x36 to 36x48) for kitchen light, non-historic home, new header required
You have a 1970s ranch home in Round Lake Beach (non-historic zone). Your kitchen has a 24x36 fixed window; you want to replace it with a larger 36x48 opening to increase natural light. Because the opening size is changing, a full building permit is required. This is not a like-for-like replacement; it's a structural modification. You must file a building permit with a plan set showing: (1) the new opening dimensions, (2) the required header size (determined by span and load — a 12-foot span typically requires a 2x10 or 2x12 header, or engineered beam); (3) wall framing plan showing removal and support of existing framing; and (4) verification that the new opening does not violate property-line setbacks or create egress issues. The Building Department will review the plan (1-2 weeks) to ensure structural adequacy and code compliance. Once approved, you can begin work. A framing inspection is required after the header is installed and before drywall closure. A final inspection occurs after the window is installed and trimmed. Permit cost: $250–$400 (based on estimated project cost, typically 1.5-2% of $8,000–$15,000 renovation value). Header installation and framing work requires a licensed contractor; DIY is not recommended (structural). Contractor cost for header and rough framing: $1,500–$2,500. Window cost: $600–$1,200. Trim and drywall: $800–$1,500. Total project: $3,200–$5,200 plus permits. Timeline: 2-3 weeks plan review, 1-2 days framing and inspection, 1-2 days finishing and final inspection. Total time: 3-4 weeks. This scenario is significantly more complex than Scenario A but is common in kitchen renovations.
Permit required (opening size change) | Structural plan review 1–2 weeks | Framing and final inspections required | Header engineering required | Licensed contractor mandatory | Permit $250–$400 | Framing/header $1,500–$2,500 | Window $600–$1,200 | Trim/finish $800–$1,500 | Total $3,200–$5,200

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Historic-district design review: what the HPC actually looks for

Round Lake Beach's Historic Preservation Commission uses the Secretary of Interior Standards for Historic Preservation as its framework. For windows, this means: (1) preserve original window openings (no enlargement or infill); (2) preserve original frame material and profile when possible; (3) if replacement is necessary, match the original design in material, color, proportions, and detail. The HPC will reject a permit application for vinyl windows with thick modern frames if the original home had wood windows with thin muntins — even if the opening size is identical. This is not about energy code; it's about architectural consistency and neighborhood character. When you submit your Design Review Application, include color samples, material specifications, and photographs of existing windows and nearby comparable homes in the district. The HPC meets monthly and reviews applications in batches; if your application is incomplete, it will be tabled to the next month, adding 4 weeks of delay. Many contractors do not know this and submit incomplete applications, frustrating homeowners who have already paid deposits for windows. The takeaway: if your home is in the historic district, contact the City's Historic Preservation Officer (usually part of the Planning Department) before you buy any windows. A 10-minute phone call can save you $2,000 in ordered-but-rejected windows.

Round Lake Beach's historic district is not city-wide; it is limited to specific blocks. The downtown core (roughly Round Lake Avenue from Main Street north to Fairfield) and selected lakefront properties are designated. Many homeowners assume they are in the historic district when they are not — or vice versa. The easiest way to check is to visit the City's zoning map on the municipal website or call the Planning Department. If your address is in a zone labeled 'HP' (historic preservation overlay) or 'HD' (historic district), design review is required. If not, you proceed directly to building permits. Do not rely on the age of your home to determine status; some homes built in 1900 are not in the district, while some from the 1960s are. The HPC approval letter, once obtained, is valid for 180 days; if you don't pull a permit within that window, the approval expires and you must reapply.

If you have already replaced windows without HPC approval (unpermitted), contact the City immediately to request a retroactive design-review and permit application. The penalty for operating outside the historic-district overlay is typically a cease-and-desist notice followed by a violation fine ($250–$500 per window) and a mandate to replace non-compliant windows. Many homeowners have spent $5,000–$10,000 replacing new vinyl windows with approved wood windows because they did not verify HPC requirements upfront. Honesty and proactive compliance are your best path forward if you discover a violation.

IECC energy code and U-factor compliance: the surprise code requirement

Illinois Building Code Section R612.2 exempts like-for-like window replacement from permits, but the code does not exempt the replacement window from meeting current IECC energy standards. This means your new window must have a U-factor of 0.32 or lower (for Climate Zone 5A, which includes Round Lake Beach). U-factor is a measure of heat transfer; lower is better (more insulating). Most modern double-pane insulated windows meet this requirement; single-pane and many older double-pane units do not. The NFRC label on the window's frame provides the U-factor rating. Before you order, check the label or the manufacturer's spec sheet online. Standard Andersen 400 Series, Pella 250 Series, and similar mid-range windows typically rate 0.30-0.32 U-factor and are compliant. Cheaper or specialty windows (e.g., storm windows, single-pane replacements, or windows designed for historic accuracy) often rate 0.35-0.50 U-factor and will not be accepted by Round Lake Beach if the Building Department audits your work.

The practical issue is this: if you are replacing windows and the Building Department determines that you are performing an 'energy upgrade' (replacing old single-pane with new insulated units), the project may trigger a permit even if the opening size is identical. The code language is ambiguous, but Round Lake Beach's Building Department has discretion to require a permit if the upgrade materially changes the building's envelope performance. This is enforced inconsistently — some inspectors overlook it for residential owner-occupied work; others are strict. If you're installing dozens of windows or doing a whole-home replacement, contact the Building Department in advance to confirm whether a permit is required. For a few windows, the risk is low, but it is non-zero.

If you're in an older Round Lake Beach home and want to replace windows for energy efficiency, you may qualify for rebates from ComEd or Nicor Gas (Illinois's major utilities). These rebates require that the windows meet IECC standards and may require a permit and final inspection to qualify. Budget $50–$150 per window in rebate; the rebate is typically issued 4-6 weeks after you submit proof of purchase and installation. This can offset the cost of a permit and inspection. Check ComEd's website for current rebate programs and requirements.

City of Round Lake Beach Building Department
Round Lake Beach City Hall, 101 W. Rollins Road, Round Lake Beach, IL 60073
Phone: (847) 546-2500 (City Hall main — ask for Building Department or Building Inspector) | https://www.roundlakebeachil.gov (check 'Building & Planning' or 'Online Services' for permit portal URL)
Monday–Friday, 8:00 AM – 5:00 PM; closed city holidays

Common questions

Do I need a permit to replace my windows if they're the exact same size?

Not in most cases. Illinois Building Code exempts like-for-like window replacement (same opening size, same operable type) from permits. However, if your home is in Round Lake Beach's historic district, you must obtain HPC design approval first. If the existing window is an egress window in a bedroom, the sill height must remain below 44 inches to maintain the exemption. If you are upgrading from single-pane to insulated double-pane windows, Round Lake Beach may classify the work as an energy upgrade, which can trigger a permit. Call the Building Department with your address and window specifications to confirm.

My home is in the historic district. What does the HPC require for window replacement?

The Historic Preservation Commission requires that replacement windows match the original design in material, color, profile, and proportions. Typically, this means wood or wood-clad aluminum frames (not vinyl) with thin muntins matching the original. You must submit a Design Review Application with color samples, material specs, and photos of your existing windows and nearby comparables. The HPC review takes 4-6 weeks. Once approved, you then file the building permit. Design review approval is a separate step from the building permit and is required even for same-size replacements in the historic district.

What's the U-factor requirement for window replacement in Round Lake Beach?

Replacement windows in Round Lake Beach must meet the IECC requirement of 0.32 U-factor or lower (Climate Zone 5A). Check the NFRC label on the window frame or the manufacturer's spec sheet before purchase. Most modern double-pane insulated windows meet this standard. Single-pane and older double-pane windows typically do not. If you order a non-compliant window, it will fail inspection and you will be required to replace it at your cost.

Is a permit required if I'm enlarging the window opening?

Yes. Any change to the opening size triggers a full building permit. You must submit a structural plan showing the new opening dimensions, the required header size, and wall framing. The Building Department will review the plan for structural adequacy and code compliance. Framing and final inspections are required. This is significantly more complex and costly than a same-size replacement. Expect 2-3 weeks for plan review and 3-4 weeks total project timeline. A licensed contractor is required; DIY is not recommended.

What if my basement bedroom egress window's sill is higher than 44 inches?

If the sill is above 44 inches, a simple replacement in the same opening will not be code-compliant. IRC R310.1 requires bedroom egress windows to have a sill height of 44 inches maximum. You have two options: (1) file a full permit to lower the sill and reframe the header (costly, $1,500–$2,500); or (2) leave the window as-is and declare the bedroom non-compliant for egress, which may affect resale value and trigger code-violation notices. Contact the Building Department to discuss your options before replacing the window.

Can I install windows myself, or do I need a licensed contractor?

For like-for-like replacements requiring no permit, you can install windows yourself if you own the home and it is owner-occupied. If a permit is required (egress, opening enlargement, historic district, energy upgrade), a licensed contractor is typically required, though owner-builders can pull permits in some cases — contact the Building Department to confirm. For structural work (headers, framing enlargement), a licensed contractor is mandatory and strongly recommended for safety and code compliance.

How long does a window-replacement permit take in Round Lake Beach?

Like-for-like replacements outside the historic district require no permit and take no time — you just install and finish. If a permit is required, expect 1-2 weeks for plan review (over-the-counter submission) or 3-4 weeks (mail submission). Historic-district design review adds 4-6 weeks before the permit is filed. Final inspection is scheduled 3-5 business days after you notify the Building Department that work is complete. Total timeline: 3-4 weeks for simple permits, 6-10 weeks if historic-district approval is required.

What happens if I replace windows without a permit when one was required?

You risk a stop-work order, fines of $100–$500 per window, potential lining or property lien, and mandatory correction at your cost. Unpermitted work may also trigger mortgage or refinance denial and can affect resale value (title insurance may exclude coverage). If discovered during a home sale disclosure, buyers may demand removal or refuse to purchase. Contact the Building Department immediately to file a retroactive permit application if you discover you needed a permit after installation.

Do I need tempered glass for my replacement windows?

Tempered glass is required by code within 24 inches of doors and within 60 inches of bathtubs or shower enclosures. If your replacement window is in one of these zones, the new window must be tempered safety glass. This is a specification, not a permit trigger, but failure to order tempered glass will result in a failed inspection and forced replacement at your cost. Check the NFRC label or order specifications to confirm tempered-glass status before purchase.

Are there rebates or incentives for energy-efficient window replacement in Round Lake Beach?

ComEd and Nicor Gas (Illinois's major utilities) offer rebates for IECC-compliant window replacement. Rebates typically range from $50–$150 per window and are paid after you submit proof of purchase and installation. Some rebate programs require a permit and final inspection to qualify. Check ComEd's and Nicor Gas's websites for current programs, eligibility, and application procedures. Rebates are processed 4-6 weeks after submission.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current window replacement (same size opening) permit requirements with the City of Round Lake Beach Building Department before starting your project.