How to Start a Window Installation Business

How do you start a window installation business from zero?

Learn to install to ASTM E2112, register an LLC, bind liability insurance, get EPA lead-safe certified, open a distributor trade account, then start with fogged glass swaps before selling whole-house jobs.

This trade is judged on water, not looks. A window that leaks two winters after you set it is a callback, a drywall repair, and a review that follows you around. The written standard is ASTM E2112, current edition E2112-23, Standard Practice for Installation of Exterior Windows, Doors and Skylights. It assumes you already have basic carpentry skills and it spends its pages on one idea: keep the building envelope continuous, whether the wall is a barrier system or a membrane and drainage system. Learn it before you learn sales.

Your first paid work should be small. Fogged glass swaps and single window replacements are fast, low risk, and they put you inside houses that have twenty more openings in the same condition. A $400 sealed-unit job that turns into an $8,000 whole-house quote six months later is the normal path in this business.

Open a trade account with a local window distributor in week one. Contractor pricing runs roughly 25 to 30 percent below retail, and vinyl units bought on a trade account typically land at $115 to $275 each against a retail median near $251. Without that account you are quoting jobs at the same material cost your customer can see online, and you will lose every bid.

• Learn the install standard. ASTM E2112-23 governs flashing, sealant joints, and envelope continuity for windows, patio doors, and skylights.
• Get FGIA InstallationMasters certified. Self-study registration is $400 for replacement-only or new-construction-only, or $425 combined. InstallationMasters 3.0 rolled out in June 2026.
• Become an EPA Lead-Safe Certified Firm with at least one trained renovator. Replacing a window in a pre-1978 house disturbs paint, and that rule is federal no matter what your state says about licensing.
• Register an LLC, get an EIN, and open a business bank account. Secretary of State filing runs $50 to $500.
• Check your state. About 44 states require a state contractor license, and thresholds start at $500 in Maryland and $1,000 in California, Arizona, and Virginia.
• Bind insurance. General liability for door and window installers averages about $83 per month or $1,000 per year. Add workers comp before your first employee touches a ladder.
• Open a distributor trade account so you buy units at 25 to 30 percent below retail.
• Buy the core kit: a 12-inch sliding miter saw, a cordless reciprocating saw, glass suction lifters, pro caulk guns, a foam gun, levels, and a multi-position ladder. Budget $5,000 to $10,000 for a fully equipped truck.
• Sell small first. Quote fogged sealed-unit swaps at $150 to $600 and single window replacements at $700 to $1,200, then work those homes into whole-house quotes.

How much does it cost to start a window installation business?

Most window installation businesses start for $10,000 to $50,000 all-in. A lean start behind a truck you already own, with a new enclosed trailer, saws, insurance, and licensing, runs $10,000 to $18,000.

The vehicle decision drives everything else. A new 2026 Ford Transit 250 cargo van starts at $51,795, and the high roof extended length version at $56,395. A new 6x12 single-axle enclosed trailer behind a truck you already own costs $3,395 to $5,899, with models like the Stealth 6x12 at $4,199 and the Cargo Mate E-Series at $4,899. Either one needs a plywood A-frame rack down the middle so units travel on edge, because glass laid flat in a bouncing box is glass that arrives cracked. Buy the van in year three with revenue, not in week one with a loan.

The saw, reciprocating saw, hand tool, and staging lines below are itemized so you can see what to defer, but together they are the same thing the trade calls a fully equipped installation truck at $5,000 to $10,000. Do not budget both. What is not in the table is EPA lead-safe firm certification and renovator training, which every pre-1978 job requires and which renews on a five-year cycle. Price it with your local training provider before you quote your first 1960s ranch.

Plan for reserves, not just gear. The common guidance is $15,000 to $40,000 in startup capital plus three months of operating expenses. Counting insurance, marketing, and a full year of operating cost, a real first year in this trade absorbs $80,000 to $150,000 against a $250,000 to $500,000 revenue target. The gear is the cheap part.

What licenses, certifications, and insurance do you need?

There is no national window installer license. About 44 states require a state contractor license, thresholds start at $500 in Maryland, and EPA lead-safe certification is federal for pre-1978 homes.

Roughly 72 percent of states have a state-level general contractor license and 44 states require one for general contracting. New York, Texas, Ohio, Pennsylvania, Illinois, and Colorado have no statewide requirement and license at the city or county level instead, which is not the same as no license. What triggers the requirement is usually contract value. Maryland is $500 per residential home improvement contract. California, Arizona, and Virginia are all $1,000, with California raised from $500 by Assembly Bill 2622 effective January 1, 2025. North Dakota is $4,000, Tennessee $25,000, and Alabama $100,000. A single bay window can cross most of those numbers, so check your board before you write a proposal.

The license usually has a window-specific flavor. California offers the Class C-17 Glazing license through the CSLB, whose scope covers selecting, cutting, assembling, and installing glass and glass-substitute materials plus fabricating and glazing frames, panels, doors, and sashes. Florida has a Window and Door Installation Specialty Contractor license for installing, replacing, repairing, and servicing exterior windows and doors, hurricane protection, and shutters where no structural change is involved. Oregon uses a CCB Residential Specialty Contractor registration, Maryland the MHIC home improvement license, and Virginia a Class A, B, or C license tiered by contract value.

The one credential that applies in all fifty states is federal, not state. Pulling a window out of a home built before 1978 disturbs paint that is presumed to contain lead, so the company must be an EPA Lead-Safe Certified Firm and the crew lead must hold current renovator training, renewed every five years. Post the sign, contain the work area, and keep the records. It is also a selling point on exactly the housing stock with the worst windows.

Costs are real but not scary. California charges a $450 application fee plus a $200 initial license fee for a sole owner, and requires a $25,000 contractor license bond set by Senate Bill 607, which you actually buy for $145 to $225 a year. Florida runs a $295 Pearson VUE exam, a $249 DBPR application, a $500 to $2,000 CPA financial statement, $500 to $1,500 of required reference books, and a $209 biennial renewal with 14 hours of continuing education. Oregon comes in at $700 to $1,400 all-in including 16 hours of pre-license training and a $60 test fee, with a $15,000 bond for Residential Specialty.

Insurance is where window work catches a break. Door and window installation contractors average $83 a month or $1,000 a year for general liability, because the trade is classed lower risk than roofing or framing. Small contractor $1M/$2M policies generally run $750 to $2,500 a year, and Florida runs higher at $1,500 to $5,000. Workers comp is the bigger number once you hire: door and window installation companies average $228 a month or $2,734 a year, governed by NCCI class code 5462, Glazier, Away From Shop and Drivers. Certification is voluntary but sells: FGIA InstallationMasters at $400 to $425 self-study, with a one-day class and written exam for replacement work and two days for the rest.

How much should you charge for window installation?

Standard replacement windows install for $700 to $1,200 each, national average $1,047. Ten-opening whole-house jobs run $5,000 to $15,000, and basement egress windows average $4,216 over two to three days.

Know which lever you are pulling. Labor is 30 to 50 percent of a replacement job, and it splits cleanly by method: an insert or retrofit install into a sound existing opening is $75 to $200 per window of labor, a full-frame tear-out is $200 to $500, and a complex opening on an upper story or one needing structural modification runs $600 and up. Frame material is the other lever. Vinyl installs at $450 to $800 per window and wood at $875 to $1,865, so ten openings in vinyl is $4,500 to $8,000 of installed product while the same ten in wood is $8,750 to $18,650. Sell the frame material before you sell the price.

Worked example. Dave quotes a ten-window vinyl insert job on a single-story ranch at $795 per opening, which is $7,950 and sits inside the $5,000 to $15,000 band for ten windows. His units cost $195 each on his trade account, or $1,950, and consumables (low-expansion foam, backer rod, sealant, shims, trim coil) add about $275. A two-person crew sets ten inserts in two days, so 16 helper hours at $25 an hour plus payroll tax and comp is about $33 loaded, or $528, and Dave's own 16 hours cost the same $528. Direct cost is $3,281 and the job leaves $4,669. That is not profit. It has to cover the $1,000 liability policy, the trailer, fuel, the phone, the quotes that never close, and the weeks nobody books, which is how a 59 percent job margin becomes the 8 to 15 percent net the trade actually keeps.

Price egress separately and price it high. A basement egress window is a structural job, not a commodity swap: national average $4,216, typical range $2,718 to $5,878, and complex jobs pass $10,000. It takes two to three days for excavation, saw-cutting the foundation, framing, and setting the window and well. The code numbers you are selling against are IRC Section R310: a net clear opening of at least 5.7 square feet, a sill no more than 44 inches above the floor, operation from inside without keys or tools, and a window well of at least 9 square feet with a projection and width of at least 36 inches. Every basement bedroom needs its own opening.

Offer volume pricing on purpose. Doing a whole house at once is normally 10 to 20 percent cheaper for the customer than replacing openings one at a time, and it is far more profitable for you because you set up once, order once, and pull one permit. Quote per-opening pricing on the same sheet so the discount is visible.

How do you get your first window installation customers?

Start with fogged glass and single window swaps, which sell fast and seed bigger jobs. Door-hang a late-1990s subdivision, build a Google Business Profile, and recruit home inspectors and realtors as referral partners.

Your best lead source is a subdivision built in one year, and the year matters. A street of 1978 single-pane aluminum sliders does not fog, it sweats and ices at the frame, and it sells on drafts and condensation. A street of 1998 builder-grade double-pane vinyl is different: those sealed units are hitting the end of a 10 to 20 year seal life all at once, so the fog is visible from the sidewalk and the homeowner does not need convincing that anything is wrong. Walk the 1998 street first.

Worked example. You spend $300 on roughly 2,000 printed door hangers and two weekends walking that late-1990s subdivision. Hang them on the knob, never in the mailbox, which is a federal offense. At a half to one percent response that is 10 to 20 calls. Quote them within 24 hours and expect to book about three. Two fogged sealed-unit swaps at $400 each is $800, and one six-window vinyl insert job at $780 per opening is $4,680, so that $300 returns about $5,480 in booked revenue. Even the pessimistic version, one $400 glass job, pays back the flyers and puts your yard sign on that street.

Build referral partners who see failed windows before you do. Home inspectors flag fogged glass and missing basement egress on nearly every report. Realtors need repairs closed before settlement and they need them fast. Remodelers and deck builders hit patio door swaps constantly and usually do not want to own the glass. Property managers turn units and need cheap, fast, correct. Three good partners will out-produce any ad budget you can afford in year one.

Then do the digital minimum. A complete Google Business Profile with real job photos, an accurate service area, and a habit of asking for the review the day the sealant skins over. A yard sign at every install for a week costs a few dollars and works because your finished job is the ad, and on a street of identical houses the neighbors already know what their own windows look like.

What tools, equipment, and software does a window installation business need?

The core kit is a sliding compound miter saw, a cordless reciprocating saw, glass suction lifters, pro caulk guns, a foam gun, levels, and a multi-position ladder. Budget $5,000 to $10,000.

Buy the saws once. A DEWALT DWS780 12-inch double-bevel sliding compound miter saw lists at $669 and street prices around $649, dropping to $499 on sale. The DWS779 makes the same cut without the XPS shadow light for $449, and for a startup that is the smarter buy. For tear-outs, the Milwaukee M18 FUEL SAWZALL 2821-20 bare tool is $249 and commonly discounted near $199, or $379 as the 2821-21 kit with a 5.0Ah battery, charger, and case. A metal-cutting blade in that saw is how you cut the nail fin free behind the siding without pulling the siding off. Add a cordless oscillating multi-tool for interior stops and blind stops, which a reciprocating saw will destroy.

The glazing-specific tools are what separate you from a general handyman. Pro cartridge caulk guns like the Albion B12 B-Line at about $51 each, or $508 for a case of ten, have a 12:1 thrust ratio, a rotating half-barrel, and a built-in puncture wire, which matters when you are running a hundred feet of sealant joint in the cold. Suction lifters, whether two-cup Bohle Veribor style or Wood's Powr-Grip vacuum pads, are how you set glass alone without dropping it, and the professional vacuum lifters are quote-only through glass distributors. A Great Stuff Pro 14 dispensing gun runs about $21 and pairs with low-pressure window and door foam, which will not bow a jamb the way standard gap filler does. Add an aluminum trim brake when you start capping exterior wood trim, because a hand-bent cap is the tell that you are new.

Software should stay thin for the first year. You need a quoting sheet priced per opening with separate lines for unit, labor, and trim, a calendar, an invoicing app that takes card and ACH, and a photo folder per job with before, during flashing, and after shots. That flashing photo is your defense on any water callback. Add a CRM when you are carrying more than about ten open quotes at once.

What should the first 90 days look like?

Weeks 1 and 2 cover licensing, insurance, lead certification, and a distributor trade account. Weeks 3 to 6 deliver your first paid installs. Weeks 7 to 12 build whole-house quotes.

Time your launch against the calendar. Starting in February or March puts your first paid installs right as the spring ramp begins and homeowners come out of winter aware of every draft and fogged pane. Starting in October means your first 90 days land in the slow season, which is survivable if you lead with sealed-unit swaps and interior-access work, but it is a harder first quarter.

What mistakes kill new window installation businesses?

The killers are water leaks from bad flashing, mismeasured openings that force reorders, quoting whole-house jobs at retail material cost, taking deposits you spend, and confusing a 35 percent markup with a 35 percent margin.

• Breaking the envelope. ASTM E2112 exists because the flashing and sealant details are where windows fail, not the glass. A leak found two winters later costs you the drywall, the paint, the window, and the neighborhood.
• Mismeasuring. Windows are made to order and non-returnable. One wrong opening on a ten-window job stalls the whole install, and you eat the unit. Measure three points on width and three on height, twice, and order to the smallest.
• Ignoring lead. Every window you pull from a pre-1978 house disturbs presumed lead paint. Working without EPA lead-safe firm certification is a federal penalty, and the housing stock with the worst windows is exactly the housing stock the rule covers.
• Quoting at retail material cost. Retail vinyl runs a median of $251 per unit while trade pricing medians $169. Without a distributor account you are 25 to 30 percent behind before you start.
• Confusing markup with margin. To keep a 20 percent profit you mark up 25 percent, for 30 percent profit you mark up 42.85 percent, and a 35 percent gross margin needs a 53.8 percent markup, not 35. This single error quietly erases the year.
• Promising a warranty you do not control. Manufacturer glass warranties typically run 10 to 20 years and do not cover labor. Say so in writing at signing, because seals fail at 10 to 20 years and no manufacturer guarantees otherwise.
• Selling the old tax credit. The Section 25C Energy Efficient Home Improvement Credit, worth up to $600 a year on qualifying windows, expired after December 31, 2025 under the One Big Beautiful Bill Act. Windows placed in service in 2026 do not qualify. Promising it is a refund request waiting to happen.
• Quoting impact and aluminum work on stale prices. 2026 import tariffs pushed aluminum-frame impact window pricing up 8 to 15 percent while vinyl-frame impact rose only 4 to 6 percent, and Miami-Dade and Broward jobs add 10 to 15 percent for NOA-rated product.
• Spending the deposit. Window units are ordered and paid for weeks before install. A deposit spent on last month's expenses turns into a job you cannot order and a customer who calls the licensing board. Several states also cap what you may collect up front, so check before you write the contract.

Is a window installation business worth it? What can you actually make?

Yes, if you sell whole-house jobs. A first-year window company can realistically target $250,000 to $500,000 in revenue, with gross margins near 25 to 30 percent and net profit around 8 to 15 percent.

The honest picture: year one absorbs $80,000 to $150,000 all-in across insurance, marketing, vehicle, and operating expense against a $250,000 to $500,000 revenue target. Windows and doors run margins in the 25 percent range for the installing contractor, with 20 to 30 percent gross typical for trades carrying this much material, and general contractors keep 8 to 15 percent net. That is $8,000 to $15,000 kept per $100,000 of revenue, which sounds thin until you notice the volume a two-person crew can move in a summer.

Do the crew math, and respect the calendar. One crew cannot be in two driveways at once, so build the week out of days. Ten vinyl inserts take a two-person crew two days at $7,950. A patio door is one day at $2,500. That leaves two days for four sealed-unit swaps at $400, or $1,600. A full peak week bills $12,050, and 26 peak weeks is $313,300. The other half of the year is not zero: eight egress jobs at $4,216, booked into the September and October shoulder before the ground freezes, adds $33,728. That is about $347,000 from one truck, inside the $250,000 to $500,000 first-year band. The ceiling is not the price per window, it is how many openings your crew can set correctly in a day.

Wages tell you what the work is worth. Window installers average $70,458 a year or $33.87 an hour nationally, with the 25th to 75th percentile band at $40,000 to $60,000 and the top 10 percent at $170,000. That top figure is not a wage, it is an owner or a lead who sells. If you can install to standard and also close a whole-house quote in the living room, you are worth several times the crew rate, and that spread is the business.

When is the busy season for window installation?

Summer is peak, spring is the ramp, and the same windows sell for 20 to 25 percent more in July than in March. Late fall and winter belong to glass repair.

Summer is the busiest time of year for any established window contractor, with waits of weeks to months for a spot on a good crew's schedule. That backlog is your opening as a new outfit: in July you are the crew that can actually start next week. Price accordingly, because peak pricing runs 20 to 25 percent above March for the identical product.

Cash flow is front-loaded April through September, which means the winter trough has to be planned in July, not discovered in December. Run sealed-unit and fogged-glass swaps, storm windows, and interior-access work through the cold months, and check the low-temperature application range on your sealant before you tool a joint in January. Homeowners shopping the March to April and September to October shoulder know they are in the discount window, so sell them a firm start date and a short lead time instead of cutting price again.

How do you compete with the big window dealers and franchises?

Do not fight on price alone. Big dealers carry a 40 to 60 percent distributor markup, a dealer markup, and sales commission inside their number, so you can quote lower and hold a better margin.

Understand where their price comes from. The chain runs manufacturer to regional distributor at a 40 to 60 percent markup, then to a local dealer at another 20 to 30 percent, then to the homeowner. A national brand's in-home sales call adds commission and a scripted discount on top of that. You buy from the same distributor at 25 to 30 percent below retail and you carry no commission, so you can quote a $795 opening where they quote $1,200 and still clear more per window than the subcontracted crew doing their install, which is typically paid $75 to $200 per opening in labor.

Beat them on knowledge, not just number. Know the spec language they use: NAFS, the North American Fenestration Standard AAMA/WDMA/CSA 101/I.S.2/A440-22, is what sets a unit's Performance Grade and Design Pressure, and those are the numbers a plans reviewer or inspector will ask for. Know ENERGY STAR Version 7.0, effective October 23, 2023, which requires Northern zone windows to hit a U-factor of 0.22 or lower with SHGC of 0.17 or higher, and Northern zone patio doors at 0.26 or lower. A homeowner who has sat through two brand pitches can tell within a minute who actually knows this.

Then be the one who shows up. A quote within 24 hours, a photo of the flashing on every job, and a phone that gets answered beat a brand name more often than new contractors expect. The national outfits win on trust and lose on responsiveness. Take the second one.