Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Any new window or door opening in Largo requires a permit, no exceptions. Even if you're replacing an existing opening with a larger one, or cutting an entirely new opening, the City of Largo Building Department treats it as structural work requiring a framing permit, impact-rating verification (if in the hurricane zone), and three inspections.
Largo sits in Florida's HVHZ (High Velocity Hurricane Zone), which means the city enforces stricter wind-load and impact-glazing rules than inland Florida towns. The City of Largo Building Department requires ALL new window and door openings—whether load-bearing or non-load-bearing walls—to be permitted and inspected. Unlike some Florida municipalities that rubber-stamp standard-size openings, Largo requires you to submit a site plan or floor plan showing the opening location, header size (if load-bearing), and exterior flashing/house-wrap details. If your opening is in the HVHZ (which includes most of Largo), you must specify impact-rated glazing (Miami-Dade or ASTM E1886/E1996 rated) and design wind speed (typically 130 mph for Largo). The permit fee is typically $250–$600 depending on opening size and wall type. Plan for 2–4 weeks review and three separate inspections: framing (header), exterior cladding, and final sign-off.

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

Largo window and door opening permits—the key details

Largo is in Florida's High Velocity Hurricane Zone (HVHZ), a designation that trickles down to almost every building rule in the city. The Florida Building Code (FBC), which Largo enforces, requires that any new window or door opening—whether in a load-bearing or non-load-bearing wall—be permitted, have a detailed framing plan, and be inspected twice (framing and final). The rule is codified in FBC Section 612 (glazing requirements) and FBC Section 704 (exterior walls). If your opening is load-bearing, you must submit a structural header design or an engineer's letter showing that the header (beam) is sized correctly for the wall loads above it. This is the single most common rejection from the City of Largo: applicants submit plans with no header size, no calculation, and no span table. The header must be stamped by a licensed engineer if the opening is larger than 4 feet wide, the wall carries roof/floor load, or you're opening up more than 25% of the wall's length.

Largo's coastal HVHZ status also means impact-rating is mandatory for most window and door openings. You cannot install standard (non-impact) glass in the HVHZ; the FBC requires that all glazing meet ASTM E1886 and E1996 at design wind speeds of 130 mph (the benchmark for Largo and much of Pinellas County). This means you must specify Miami-Dade County or equivalent impact-rated windows/doors on your permit application. If you fail to note this, the permit officer will reject the application and request proof that your chosen product carries an impact rating. Cost impact: impact-rated windows run 30–50% more than standard ones, so budget an extra $1,500–$4,000 for a typical 3-window project. The city does not waive this requirement for interior openings or single-pane doors; every pane of glass going into a new opening must be impact-rated if the opening is within the HVHZ boundary. Largo publishes a list of approved impact-rated manufacturers on its building department website; cross-check your window spec against that list before you order.

Exterior detailing is the second-most-common rejection trigger in Largo. The FBC requires that all new window and door openings include flashing (metal or asphalt-impregnated membrane) to prevent water intrusion, and that house-wrap or water-resistant barrier be lapped and sealed around the opening per FBC Section 703.2. Many applicants submit framing plans with no flashing or house-wrap detail, assuming the contractor will 'figure it out.' Largo's inspector will red-tag this and send the plan back for a section drawing showing flashing, wrap overlap, and caulk/sealant detail. You do not need an architect to draw this—a simple 1:6 scale detail sketch showing the window flanged against the house-wrap, flashing lapped downward and outward, and caulk bead is sufficient. If the opening is on a wall facing the Gulf (or any salt-spray exposure), the inspector may request higher-grade flashing or marine-grade sealant; budget an extra $200–$400 for material and labor.

Load-bearing walls in Largo are often hidden or ambiguous on old plans. If you are opening a wall that runs perpendicular to floor joists, or that sits directly below a rafter or truss, it is load-bearing and requires a header. The rule is in IRC R602.10 (wall bracing and support); Largo enforces this strictly. If you remove the studs in a load-bearing wall without a header, the weight above collapses into the opening, and the building sags or cracks. The City of Largo will not sign off on the framing inspection until a licensed engineer or a contractor with a PE-stamped framing plan certifies the header size. For openings under 4 feet wide in typical residential walls (8 ft floor-to-floor, roof load only), you can often use a standard double 2x10 or 2x12 header, but Largo requires you to state this on the permit—verbal assurance to the inspector is not enough. Larger openings, or openings in walls carrying significant live load (like load-bearing interior walls), may require a built-up beam or a steel angle. If you don't know whether a wall is load-bearing, assume it is and have an engineer assess it; the $200–$400 engineer's cost is far cheaper than a rejected permit and a second submission.

The City of Largo's permit timeline is typically 2–4 weeks for a straightforward window or door opening, provided the plan is complete and passes the first review. If you submit an incomplete plan (no header size, no flashing detail, missing HVHZ impact rating, or no egress calculation if the opening is in a bedroom), add 1–2 weeks for resubmission and re-review. Inspections happen at three stages: framing (after the header is installed and braced, before drywall or exterior cladding is applied), exterior cladding (after flashing and wrap are installed, before paint or exterior finish), and final (after everything is complete and the opening is glazed and functional). Each inspection typically takes 1–2 hours; plan your contractor's schedule around these windows. The City of Largo operates Monday through Friday, 8 AM to 5 PM, with no walk-in inspections; schedule all three inspections at least 48 hours in advance through the city's online portal or by phone. The total permit cost, including plan review and inspections, is typically $250–$600 depending on opening size and whether the wall is load-bearing (structural review adds $100–$150 to the fee). Owner-builders are permitted under Florida Statute § 489.103(7), but Largo still requires the same plan details and inspections; being the owner does not exempt you from the HVHZ impact-rating or flashing requirements.

Three Largo new window or door opening scenarios

Scenario A
Two new 4x4 casement windows in a non-load-bearing gable wall, exterior foam sheathing, HVHZ impact-rated, no new header required
You're converting a small bedroom in a 1970s ranch home in the Azalea Grove neighborhood (east Largo, HVHZ). The south wall is a gable (triangular section above the eave line), and it is NOT load-bearing—all the load above is carried by the roof trusses that sit on the exterior walls below. You want to cut two new 4x4 windows to improve light and ventilation. Because the wall is non-load-bearing, you do not need a header; Largo allows a simple cripple-stud frame (short studs above and below the opening). However, because this is a new opening AND you are in the HVHZ, you must specify impact-rated glazing (Miami-Dade certified, 130 mph). The city requires you to submit a floor plan showing the two window locations, a 1:6 scale section detail showing flashing lapped downward and outward, house-wrap sealed and taped around the opening, and a product spec sheet or cut sheet for the impact-rated windows (e.g., Marvin, Anderson, or PGT Innovations). The plan must also note egress (IRC R310): if either window is in a bedroom, it must have at least 5.7 sq ft of net glass area, 24-inch width, and 37-inch height to serve as an emergency exit. Assuming both windows meet egress, the permit is granted in about 2 weeks. The inspector will visit three times: (1) framing—check the cripple-stud layout, flashing installation, and house-wrap seal; (2) exterior cladding—verify flashing laps, caulk bead, and sealant coverage; (3) final—inspect the glazing installation, screen fit, and hardware operation. Total cost: $300–$400 permit fee, plus $3,500–$5,500 for impact-rated windows and installation (about $1,750–$2,750 per window installed, plus flashing and sealing). Timeline: 3–4 weeks from permit issuance to final inspection.
HVHZ impact-rated windows required | Non-load-bearing wall = no header | Egress 5.7 sq ft minimum per bedroom | Flashing and house-wrap detail required | Permit fee $300–$400 | Material + labor $3,500–$5,500
Scenario B
New 6-foot wide patio door opening in a load-bearing exterior wall, second floor, limestone block structure, double 2x12 header required, engineer-stamped plan
You own a 1960s concrete-block Florida home in Seminole Woods (north Largo, HVHZ) with a second-floor bedroom overlooking the street. You want to install a new sliding glass patio door (6 feet wide, 8 feet tall) to access a new balcony. The exterior wall is load-bearing—it sits directly below second-floor joists and the roof truss system. Because the opening is 6 feet wide and the wall is load-bearing, you must provide a structural header (beam) sized to carry the load above. A double 2x12 southern pine header is typical for this span and load; however, Largo requires an engineer's letter or a PE-stamped framing plan to confirm the header size, bearing length (18 inches minimum on each side), and uplift bracing. The engineer will charge $200–$350 for the letter. You must also submit an impact-rated product spec for a 6x8 patio door (e.g., PGT Innovations, Marvin, or Pella impact-rated slider) and a detailed flashing plan showing the threshold pan (sloped downward, weep holes at each corner), head flashing lapped over the house-wrap, and side-flange caulk. If the wall is stone or block, the plan must show how the brick/block mold or jamb extension will bridge the opening and tie into the flashing. Because this is a second-floor opening in HVHZ, the inspector will also verify that the railing (if the balcony is open) meets IRC R312 (4-inch ball rule, 36-inch rail height). The City of Largo will require 3–4 weeks for review because of the structural engineer review step. Inspections: (1) framing—header installation, bearing, bracing, and cripple stud layout; (2) exterior—flashing, house-wrap, sealant, and cladding (brick/block/foam); (3) final—glazing, hardware, railing compliance, and threshold waterproofing. Total cost: $400–$600 permit fee, plus $200–$350 engineer's letter, plus $5,000–$8,000 for impact-rated door, header material, flashing, installation, and balcony framing. Timeline: 5–6 weeks from submission to final inspection.
Load-bearing wall = double 2x12 header required | Engineer letter stamped (PE) required | HVHZ impact-rated patio door required | Flashing and threshold pan detail required | Railing IRC R312 compliance | Permit fee $400–$600 | Engineer $200–$350 | Material + labor $5,000–$8,000
Scenario C
New bedroom egress window (awning-type, 24x37 inches) in a non-load-bearing interior wall conversion, standard (non-impact) glass allowed because opening is interior, single-story retrofit
You are converting a home office into a bedroom in a single-story Largo home (Azalea Park area, HVHZ). The new bedroom is small (10x10) and sits in the interior of the home, with no exterior wall nearby. To satisfy the egress requirement (IRC R310: every bedroom must have at least one means of escape/rescue), you need to cut a new opening in a non-load-bearing interior wall that faces an exterior patio or lanai. You select a 24x37 inch awning window (the minimum egress size: 5.7 sq ft net glass, 24-inch width, 37-inch height). Here is the key: because the opening itself is in a non-load-bearing interior wall (not an exterior wall facing the street or open ocean), and the window will face a screened or roofed patio, some contractors mistakenly assume the window does NOT need impact rating. This is wrong. Largo's HVHZ rule applies to ANY new window or door opening in the high-velocity hurricane zone, regardless of whether it is exterior-facing or interior-wall-facing. If the patio faces the street or open air and could be subject to wind-borne debris in a hurricane, the window must be impact-rated. However, if the opening faces a fully enclosed screened room or a roofed lanai that itself meets HVHZ enclosure standards, Largo may waive the impact requirement for that specific opening—but this requires explicit written approval from the city before you file the permit. Most contractors and homeowners assume 'interior = no impact,' which is incorrect and leads to permit rejections or failed final inspections. The safe approach: call the City of Largo Building Department and describe the exact patio/lanai condition, or submit the permit with impact-rated glazing to avoid rejects. Assuming the opening faces a fully enclosed, hurricane-rated lanai, you can use standard (non-impact) glass, and the permit is straightforward: floor plan, egress dimension callouts, window spec, and a simple framing detail. The permit fee is $250–$350 (smaller project, no structural review needed). Inspections: (1) framing—stud layout, header if load-bearing (not needed here), and rough-in dimensions; (2) exterior (interior in this case)—flashing and drywall blocking around the opening; (3) final—glazing, sill pan, hardware, and egress measurement (verify 24x37 minimum). Timeline: 2–3 weeks. Total cost: $250–$350 permit fee, plus $600–$1,200 for a standard awning window and installation (no impact premium), plus framing labor $800–$1,500. Total project: $1,650–$3,050.
Non-load-bearing interior wall = no header | Egress 5.7 sq ft, 24x37 minimum | Impact-rated glass typically required in HVHZ (confirm with city for enclosed lanai exception) | Permit fee $250–$350 | Window + installation $600–$1,200 | Framing labor $800–$1,500

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HVHZ impact-rating requirements in Largo: what you absolutely must know before ordering windows

Largo lies entirely within Florida's High Velocity Hurricane Zone (HVHZ), a coastal strip that runs from Brevard County to the southern tip of the state. The HVHZ is defined by wind-speed contours (110+ mph 3-second gust design wind speed) and is mapped on the Florida Building Code maps and on county assessment roll data. The City of Largo enforces FBC Section 612 (Interior Finishes and Wall and Ceiling Coverings) and Section 704 (Exterior Walls) with special emphasis on impact-rated glazing. Any NEW window or door opening in the HVHZ must have impact-rated glass rated to ASTM E1886 and E1996 at 130 mph (the design wind speed for Largo and most of Pinellas County). This is not optional, not waivable, and not negotiable unless the opening is in a fully enclosed, hurricane-resistant room or building (like a safe room).

Impact-rated windows are manufactured with laminated glass (a layer of polyvinyl butyral [PVB] bonded between two panes of glass) or tempered glass designed to withstand impact from wind-borne debris. When a missile (a 2x4, a sign, or a roof tile) hits impact-rated glass at hurricane speeds, the glass cracks but the PVB interlayer holds the fragments in place, so the window does not shatter inward and create an opening for wind and rain. Non-impact (standard) glass shatters and falls into the home, which is catastrophic in a hurricane: the room pressurizes, the roof lifts, and structural failure cascades. Largo inspectors take this seriously and will fail the final inspection if you install non-impact glass in an HVHZ opening. The cost premium for impact-rated windows is 30–50% above standard windows: expect to pay $1,750–$2,750 per window installed (labor included) versus $1,200–$1,800 for a standard high-end window.

When you order impact-rated windows, always request a Miami-Dade County Product Control Certificate or equivalent (NFRC, AAMA, or PCI label showing ASTM E1886/E1996 rating at 130 mph). Not all impact-rated windows sold in Florida are rated for 130 mph; some are rated at lower wind speeds and will fail Largo's inspection. Verify the product spec sheet before you buy. If your contractor or supplier cannot provide a certificate, do not order the window. The City of Largo publishes an approved manufacturer list on its building department website; cross-check your choice against that list. Popular impact-rated brands in Largo include PGT Innovations (Eze-Breeze, PGT), Marvin, Anderson, Pella, Andersen, and several vinyl/aluminum specialists. If you are replacing an existing window with a same-size (like-for-like) replacement, you are exempt from the permit requirement under FBC Section 612.2 and can use standard glass. However, if you are creating a NEW opening (wider, taller, or a new location), the impact-rated requirement applies.

Header sizing, structural review, and why the City of Largo rejects so many opening permits

The City of Largo's most frequent permit rejection for new window and door openings is a missing or undersized header. A header (or lintel) is a horizontal beam that spans across the top of an opening in a load-bearing wall, transferring the weight of the wall and roof/floor above to the studs on either side of the opening. The header must be sized based on the opening span (distance between the studs supporting it), the wall load (roof only, or roof plus floor), the lumber grade and species, and the allowable bending stress. For a 4-foot-wide opening in a typical single-story residential wall carrying only roof load, a double 2x10 or double 2x12 southern pine header is standard. For a 6-foot-wide opening, or an opening that carries floor load above (second-story wall), you need a double 2x12 or a built-up beam. For a 8-foot-wide opening or a load-bearing interior wall, you may need a steel beam or a solid-sawn 4x12 or larger.

Largo's code requires you to either (a) submit a plan with the header size clearly labeled, and a span table reference, or (b) provide an engineer's letter or PE-stamped structural design. If your opening is under 4 feet wide and the wall is clearly non-load-bearing (e.g., a gable wall in a single-story home, or an interior wall with no joists above), Largo may approve a plan with a note 'non-load-bearing opening, cripple stud frame, no header required.' However, if there is ANY doubt about whether the wall is load-bearing, you must have an engineer assess it. The engineer's cost ($200–$350) is far cheaper than a rejected permit, a second submission, and a potential structural failure that could injure someone or damage the home.

To avoid rejection, submit a detailed plan that includes: (1) a floor plan or site plan showing all window/door locations and opening dimensions; (2) a 1:16 or 1:24 scale wall section drawing showing the header size, lumber species, and bearing length on each side of the opening (18 inches minimum for residential wood headers); (3) a callout or note referencing a span table (e.g., 'Header per IRC R505.3.1 table, double 2x12 DF, 4-foot span, roof load'); (4) a detail drawing of the flashing and house-wrap around the opening; and (5) if the opening is load-bearing, an engineer's letter confirming the header size and bearing. If you do not have a detailed plan, many contractors in Largo work with a structural engineer on retainer or send the details to the engineer for a quick review (1–2 hours, $150–$250). This is far better than submitting an incomplete plan and waiting 1–2 weeks for a rejection and re-work notice.

City of Largo Building Department
Largo City Hall, Largo, Florida (exact address: search 'City of Largo Building Department address' on the city's official website)
Phone: (727) 586-7400 or visit www.largoflorida.com for the building permit line | https://www.largoflorida.com/permits (online permit portal for submission and inspection scheduling)
Monday–Friday, 8:00 AM–5:00 PM (closed weekends and city holidays)

Common questions

Can I install a non-impact window in Largo if I am in the HVHZ?

No. Largo is entirely within Florida's High Velocity Hurricane Zone, and the City of Largo Building Code requires impact-rated glazing (ASTM E1886/E1996 rated at 130 mph) for ANY new window or door opening. This is not waivable unless the opening is in a fully enclosed, hurricane-resistant safe room. Installing non-impact glass will result in a failed final inspection, a stop-work order, and you will be forced to remove and replace the window at your cost. Non-impact windows are also not insurable in Largo; your homeowner's insurance will deny a claim related to hurricane damage if it discovers unpermitted or non-code windows.

Do I need a permit to replace an existing window with a new one the same size?

No, a like-for-like window replacement (same opening size, same location) is exempt from the permit requirement under FBC Section 612.2. However, if you enlarge the opening, relocate the window, or create a new opening, a permit is required. Many homeowners think a replacement exemption covers all window work, but Largo's inspector will ask to see the old opening to confirm it was truly the same size; if it was not, you will be cited for an unpermitted opening and will need to obtain a retroactive permit or engineer's letter to validate the work.

How long does a window or door opening permit take in Largo?

Typical timeline is 2–4 weeks from submission to permit issuance, plus 3–5 business days per inspection (framing, exterior, final). If the plan is incomplete or the wall is load-bearing and requires structural review, add 1–2 weeks. Total project timeline from submittal to final inspection sign-off is usually 4–6 weeks. Expedited review is not available for window openings, but if you submit a complete, defect-free plan, you may get approved in 10–14 days.

What is a header, and do I need one for my new window opening?

A header is a horizontal beam (typically made of two 2x10 or 2x12 studs nailed together) that spans the top of a window or door opening and transfers the weight of the wall and roof/floor above to the studs on either side. You need a header if the opening is in a load-bearing wall (a wall that carries roof or floor load). If the wall is non-load-bearing (e.g., a gable wall, or an interior wall with no joists above), you do not need a header, only cripple studs to frame the opening. To determine if your wall is load-bearing, consult the original building plans or have a licensed engineer inspect it. If you are unsure, assume the wall is load-bearing and have an engineer size the header; the cost ($200–$350) is cheaper than a rejected permit or a structural failure.

Can an owner-builder pull a window opening permit in Largo, or do I need a contractor?

Owner-builders are permitted to pull permits in Largo under Florida Statute § 489.103(7), provided you are the owner of the property and the work is on your primary residence. However, Largo still requires the same plan details, inspections, and code compliance whether you are an owner-builder or a licensed contractor. The exemption does not waive impact-rating requirements, flashing details, or structural review—only the licensing requirement. Many owner-builders hire a licensed contractor to pull the permit and do the framing/glazing work, then pull the permit themselves and schedule inspections if they are doing demolition or finish work.

What happens if a neighbor complains about my unpermitted window opening in Largo?

The City of Largo Building Department will open a code-enforcement case, issue a notice of violation, and order you to either obtain a retroactive permit or remove the opening within 30 days. If you fail to comply, the city will assess daily fines (typically $100–$250/day) until the violation is corrected. Additionally, if the opening is unpermitted and failed to meet code (e.g., non-impact glass in the HVHZ, or an undersized header), the city may order forced removal and require you to hire a licensed contractor to redo the work and pull a new permit. The total cost of enforcement action, retroactive permitting, and corrective work can easily exceed $5,000–$10,000.

Do I need flashing and house-wrap details on my permit plan, or can the contractor figure it out on site?

Flashing and house-wrap details must be shown on your permit plan as a detail drawing (1:6 scale or larger, showing the window flanged against the house-wrap, flashing lapped downward and outward, caulk bead, and any special treatment for salt-spray or masonry walls). The City of Largo's inspector will not approve the framing inspection until these details are provided; if you submit a plan without them, Largo will issue a correction notice and you will have to resubmit. It is standard practice to include a simple 2–3 inch detail sketch on the same page as the framing plan; this takes 10 minutes to draw and saves you 1–2 weeks of rejection and resubmission.

What is the City of Largo's permit fee for a new window or door opening?

Permit fees in Largo are based on the valuation of the work. For a window or door opening, the typical fee is $250–$600, with most single openings in the $300–$450 range. The city calculates valuation based on the opening size, materials, and labor estimate; you will provide an estimate or use a city-provided valuation table. Expedited review fees, plan-review fees, and inspection fees are separate and may add $50–$100 to the total. Always confirm the exact fee with the City of Largo Building Department at (727) 586-7400 or on the city's permit portal before you submit, as fees may change.

If I am replacing a window with a larger opening, do I need a permit?

Yes. If you are enlarging the opening beyond the size of the existing window, it is a new opening and requires a full permit, including structural review (if load-bearing), impact-rating verification (HVHZ), and flashing/house-wrap details. Even if you are only widening the opening by 6 inches, it is considered a new opening by Largo code. The exemption for like-for-like replacement applies only if the opening size is truly identical (same width and height); if you enlarge the opening even slightly, the exemption is lost and a permit is required. This is a common misconception that leads to unpermitted work and code-enforcement action.

What inspections are required for a new window or door opening in Largo?

Three inspections are required: (1) Framing Inspection—occurs after the opening is cut, the header (if needed) is installed and braced, studs are installed, and the opening is ready for exterior cladding or sheathing. The inspector verifies the header size, bearing length, stud spacing, and bracing. (2) Exterior Cladding Inspection—occurs after flashing is installed, house-wrap is sealed and taped, and the exterior surface (drywall, foam, brick, siding) is installed around the opening. The inspector checks flashing lap direction, sealant coverage, and wrap continuity. (3) Final Inspection—occurs after the window or door is installed and glazed, hardware is operational, interior trim is in place, and the opening is fully functional. The inspector verifies glazing type (impact-rated if HVHZ), sill pan (if applicable), header bracing removal, and compliance with egress requirements (if a bedroom). All three inspections must be scheduled 48 hours in advance through the city's portal or by phone. Plan your contractor's timeline around these inspection windows to avoid delays.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current new window or door opening permit requirements with the City of Largo Building Department before starting your project.