How Long Does Window Replacement Take? Timelines and What to Expect

How Long Does Window Replacement Take? Timelines and What to Expect

In 2024, the average custom window order from a mid-tier manufacturer runs 8 to 12 weeks from order to delivery in Southern California. That means a homeowner who signs a contract in September should not expect finished windows before December, a fact most contractors bury in the fine print. This guide breaks the timeline into its actual stages, with real ranges for the Los Angeles market, so you can plan around the truth instead of a sales pitch. We’ll cover stock vs. custom windows, LADBS permit processing, single-day installation reality, and the specific milestones you should ask for in writing before signing anything.

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Quick Answer

Window Replacement services in Los Angeles typically take 6 to 14 weeks from signed contract to finished installation. The physical installation day is usually just 1 to 3 days once your windows arrive on site. The gap between those two numbers is fabrication lead time, and that is where most projects stall.

Table of Contents

• The Actual Stages of a Window Replacement Timeline
• Lead Time is the Real Timeline: Stock vs. Custom vs. Semi-Custom
• LADBS Permits: What Processing Times Look Like in Los Angeles
• Single-Day Installation Reality: How Many Windows Can a Crew Actually Do?
• What a Written Project Schedule Should Include
• Five Factors That Stall a Window Replacement (and How to Avoid Them)
• Common Mistakes to Avoid
• When to Call a Professional

The Actual Stages of a Window Replacement Timeline

Most contractors give you one number: “installation takes two days.” That answer is technically true and practically useless. A window replacement project in Los Angeles moves through five distinct stages, and each one has its own clock. Understanding them separately is the difference between a plan and a surprise.

1. Measure and order (1 to 2 weeks). A technician visits your home, measures every opening, confirms operating styles, and writes the order. This stage includes your approvals, deposit, and any design changes. Do not rush this step. A wrong measurement here becomes a 10-week delay later.
2. Fabrication lead time (4 to 14 weeks, depending on product). The manufacturer builds your windows. This is the stage almost nobody explains clearly, and it is the largest variable in the entire timeline. We cover this in depth below.
3. Delivery (3 to 7 days). Your windows ship from the factory to a local warehouse or directly to the job site. In Los Angeles, deliveries from Florida manufacturers like PGT or CGI add freight time compared to regional suppliers.
4. Permit approval (same day to 4 weeks). Los Angeles Department of Building and Safety (LADBS) handles window replacement permits differently depending on the scope of work. Some projects clear over the counter, others enter plan check. We detail this below.
5. Installation day (1 to 3 days). A two-person crew removes the old windows, preps the openings, and installs the new units. This is the shortest stage in the entire process.

When a contractor says “it takes two days,” they mean stage five. When you ask “how long does window replacement take,” you probably mean all five stages combined. In Los Angeles, that total is realistically 6 to 14 weeks, and the single biggest driver is what you ordered.

Lead Time is the Real Timeline: Stock vs. Custom vs. Semi-Custom

The question “how many days?” is the wrong question. The right question is “how many weeks between signing and delivery?” And that number swings by 4 to 10 weeks based entirely on product selection. Here is how the three categories break down in the current Los Angeles market.

Stock Windows (2 to 4 weeks total)

Stock windows are pre-built in standard sizes and sitting in a warehouse right now. You pick from what exists. Common sizes like 36×48 inch double-hungs and 24×36 inch sliders are usually available. The tradeoff is fit: stock sizes rarely match an existing opening exactly, so the installer must adjust the frame with fillers or trim work. For a rental unit or a garage, stock windows from a line like Mr-Glass get the job done fast. For a primary residence, the compromise in sightlines and weather sealing often outweighs the speed.

Semi-Custom Windows (4 to 8 weeks total)

Semi-custom means the manufacturer builds your windows to your opening measurements, but you choose from their standard materials, finishes, and hardware packages. This is the sweet spot for most Los Angeles homeowners. You get a proper fit without paying for a fully bespoke design. Lines like ViewLux and Therma-Tru sit in this category, with lead times typically running 4 to 8 weeks depending on factory backlog and glass options. If you want a specific color, a certain glass package, or an exact grid pattern, semi-custom is where you live. In our experience, about 70 percent of Los Angeles replacement projects are semi-custom.

Custom Windows (8 to 14 weeks total)

Fully custom means the manufacturer builds to non-standard dimensions, non-catalog materials, unusual shapes, or specialty glass like impact-rated laminated units. Arched tops, oversized picture windows, and true divided lites all fall here. PGT impact-rated windows, increasingly common in Los Angeles hillside zones and anywhere near a wildfire risk area, are generally custom builds. The fabrication time is real: the glass must be cut, tempered or laminated, the frame extruded or milled, and the unit assembled to spec. There is no warehouse shortcut. When a homeowner in Brentwood or the Hollywood Hills wants floor-to-ceiling glass, they are signing up for a 10-to-14-week lead time, and any contractor who promises faster is guessing.

The takeaway: product selection drives your timeline more than any other decision. Before you fall in love with a window style, ask what its actual fabrication lead time is, in writing, from the supplier your contractor actually uses.

LADBS Permits: What Processing Times Look Like in Los Angeles

Window replacement in Los Angeles requires a permit from LADBS in most cases, and the processing path depends on what you are changing. This is where Los Angeles homeowners get tripped up, because the timeline varies widely and most contractors do not volunteer the detail.

Over-the-Counter Approval (Same Day to 3 Days)

If you are replacing windows with the same size, same type, and same opening, in a standard wood-frame or stucco home, your permit often clears at the counter or through the LADBS Express Permit portal. The plan reviewer checks that the new units meet current energy code (Title 24) and that egress requirements are maintained. This is the fast path, and most straightforward replacements in Los Angeles neighborhoods like Sherman Oaks, Culver City, and Torrance clear this way.

Plan Check (1 to 4 Weeks)

Your project enters plan check if any of these apply: you are enlarging an opening, adding a new window where none existed, changing from a sliding window to a casement (which changes egress), working on a historic property, or installing windows that require structural review. Hillside zones and properties in the Coastal Zone add another layer of review. In 2024, LADBS plan check for simple window alterations averaged 2 to 3 weeks. Complex projects ran longer. If you are in a Historic Preservation Overlay Zone, like Hancock Park or Angelino Heights, expect additional review time and possibly a separate hearing.

A competent contractor pulls the permit, manages the submittal, and schedules the inspection after installation. A contractor who tells you “we don’t need a permit for windows” in Los Angeles is giving you bad advice that can surface when you sell the house. Ask the question directly: “Who pulls the permit, and which review path does this project take?”

Single-Day Installation Reality: How Many Windows Can a Crew Do?

A two-person crew can realistically replace 5 to 8 windows in a single day, depending on window type, access, and the condition of the existing frames. That is the honest number. Here is how it breaks down in Los Angeles conditions.

• Standard double-hungs or sliders in good openings: 7 to 8 per day. The old unit comes out, the new unit goes in, shim and level, foam and flash. Straightforward work on a single-story home.
• Casement or awning windows: 5 to 6 per day. More hardware, more adjustment, more time per opening.
• Large picture windows or oversized units: 2 to 3 per day. Glass this size requires extra hands, extra care, and often a lift. One 8-foot-by-5-foot picture window can consume half a morning.
• Windows with rotted or damaged frames: 3 to 4 per day. If the rough opening needs repair, new sill framing, or water damage remediation, each opening doubles in time. Los Angeles coastal homes in Playa del Rey and San Pedro deal with salt air and fog moisture, and we regularly find hidden sill rot that adds a day to the job.
• Second-story or difficult access: 4 to 5 per day. Ladder work, staging, and moving glass up and down all slow the pace. Homes in the hills with decks and narrow side yards compound this.

So a typical 12-window home in Los Angeles is a 2-day installation. A 20-window home is 3 days, sometimes 4 if conditions are rough. Anyone who promises all 20 windows in one day is cutting corners somewhere, and in our experience, the corner is usually flashing and sealing work you will never see.

What a Written Project Schedule Should Include

Before you sign any window replacement contract in Los Angeles, you need a written project schedule. Not a verbal estimate of “about two months.” A document with dates, milestones, and named deliverables. Here is what that schedule should contain at minimum.

1. Measure date and order submission date. The day your windows get ordered should be within one week of your final measurement. If the contractor cannot commit to an order-by date, they have not actually ordered anything.
2. Manufacturer order acknowledgment. Reputable contractors can produce a supplier order confirmation. This proves the lead time clock has started. Ask for it.
3. Expected delivery window. A range of 1 to 2 weeks, not a single date. Supply chains shift. A contractor who gives you a single delivery date is guessing.
4. Permit submittal date and review path. Whether the permit is over-the-counter or plan check, the schedule should say which and when it was submitted.
5. Scheduled installation dates. Once windows are confirmed in transit, you should get firm install dates with a named crew. Not “sometime next week.”
6. Final inspection and closeout date. LADBS final inspection for window permits is required in many projects. Your schedule should include it and who is responsible for scheduling it.

At Juniper Windows and Doors, every project gets a written price before any work starts, and that written price is backed by the 365-Day Done Right Promise. The schedule is part of the written agreement, not a handshake. Sean Mackey has run our Los Angeles operations since 2001, and the standard has not changed: if it is not in writing, it does not count.

If a contractor balks at putting dates on paper, that tells you something useful about how the rest of the project will go.

Five Factors That Stall a Window Replacement (and How to Avoid Them)

In 20-plus years of installations across Los Angeles, we have seen the same delays repeat. Here are the five most common stall points, with what you can do about each one before it happens.

1. Glass Package Availability

Low-E coatings, argon gas fills, and impact-rated laminated glass are all manufactured in batches. If your order calls for a glass package that is not currently in production, your lead time extends. Impact-rated glass, built to resist wind-borne debris without shattering, has longer fabrication cycles than standard glass. Ask your contractor which glass packages are currently in backlog before you select.

2. Color and Finish Decisions

Exterior frame color is a bigger decision than most homeowners expect. In Los Angeles, HOA communities like those in Playa Vista or Pacific Palisades often have specific color requirements. Waiting two weeks to pick a color adds two weeks to your timeline. Lock finish selections at contract signing.

3. Permit Corrections

LADBS plan check can return corrections. A window schedule that does not match the drawings, missing Title 24 energy documentation, or an egress issue in a bedroom window all trigger a correction cycle that adds 1 to 2 weeks. A contractor who has done this before anticipates these items. One who has not learns on your timeline.

4. Hidden Frame Damage

The old window comes out, and the rough opening is not sound. Termite damage, long-term water intrusion, or dry rot in the sill plate. Now the job scope changes mid-install. In Los Angeles homes built before 1970, this is common enough that we tell homeowners to budget for it mentally. You cannot fully prevent it, but you can ask your contractor what their change-order process looks like when it happens. At Juniper, the written price covers the scope as quoted, and any additional work is priced and approved before it proceeds. No surprise invoices.

5. HOA Approval Wait

If you live in a condo or a planned community with architectural review, HOA approval can add 2 to 6 weeks before your contractor can even pull the permit. Many homeowners forget this entirely. Start the HOA process the day you decide to replace windows, not the day you sign the contract.

Common Mistakes to Avoid

• Believing the installation-day number is the full answer. “Two-day install” tells you nothing about the 8 weeks before it. Always ask for the total timeline from contract to completion.
• Choosing windows without checking current lead times. A specific line from a specific brand, like a Therma-Tru semi-custom or a PGT impact unit, has a real backlog right now. Ask for the supplier’s current lead time in writing.
• Signing a contract without a written schedule. A verbal promise about timing has no weight in a dispute. Written milestones are the only protection you have.
• Skipping the permit. Unpermitted window replacement in Los Angeles can surface at resale and cost far more than the permit would have. A legitimate contractor pulls the permit as standard practice.
• Waiting to deal with the HOA. Condo and planned community approvals move on their own clock, completely outside your contractor’s control. File early.
• Not asking about change-order policy. Hidden damage happens. Ask what happens to the price when it does, and get the answer in writing.
• Choosing a contractor on price alone. The low bid often comes from someone who does not pull permits, does not carry proper insurance, or does not get vendor lead times in writing. Any of those will cost you more time than the savings justify.

When to Call a Professional

Window replacement is not a DIY project, and the timeline question is only the first thing worth asking a professional. If you have windows that are fogged between panes, frames that are soft to the touch, or a single failed unit in a house full of aging windows, you need a full assessment, not a quick patch. If you are considering impact-rated windows for fire or wind zones, if your home is pre-1970 with possible lead paint or asbestos concerns, or if your project involves anything beyond a simple same-size swap, call someone who does this every day. Window replacement in Los Angeles is a significant investment, and the timing details matter. Juniper Windows & Doors offers free estimates in Los Angeles. Call (682) 281-2168 to schedule yours, and get a written price and schedule before you commit to anything.

We are part of the Relay Home Co. family, and our technicians are background-checked and uniformed. Every project runs under the Relay Visibility Guarantee: a live arrival time you can track, before-and-after photos of every job, and a written price before anything starts. A real person answers our phone 24/7, so when you call, you get answers, not a voicemail maze.

Frequently Asked Questions

The Bottom Line

Window replacement in Los Angeles takes 6 to 14 weeks from contract to completion, with installation day occupying only a sliver of that total. The lead time on your chosen product is the biggest variable, followed by permit processing and hidden frame conditions. Ask for a written schedule with named milestones, confirm current supplier lead times in writing, and get your HOA process started early. The right contractor puts every date and every dollar on paper before you sign. When you are ready to get a written price and a real timeline, call (682) 281-2168 to schedule your free estimate. We are Juniper Windows & Doors, and we have been replacing windows and doors across Los Angeles since 2001. For more on what we do, see our window installation in Los Angeles and door replacement in Los Angeles pages.

Written by Sean Mackey, Owner at Juniper Windows & Doors, serving Los Angeles since 2001.