A window and door business can sell and install whole-house replacements, install for a dealer or a lumberyard, or do repairs and single doors. Selling your own jobs pays the most and needs supplier accounts and cash flow. Installing for others is steady but priced by the opening. Many start by installing for a supplier and add their own customers.
- Most states license contractors who replace windows and doors, often under home improvement rules.
- In homes built before 1978, window replacement disturbs paint. The EPA lead rule applies.
- Take a deposit before you order. Custom sizes cannot be returned.
- Measure twice, order once, and photograph every opening before you start.
1. Decide what you will offer
| Work | Who asks | Notes |
|---|---|---|
| Replacement windows | Homeowners | Big tickets, often financed |
| Entry and storm doors | Homeowners | Quick installs, steady demand |
| Patio and sliding doors | Homeowners | Heavy units, two people |
| Installs for dealers | Lumberyards, showrooms | Per opening pricing |
| Repairs, hardware and screens | Homeowners, property managers | Small jobs, set a minimum |
Siding and roofing contractors get asked about windows all the time. Tell them you install.
2. Check the license and permits
Window and door replacement usually falls under contractor or home improvement licensing, and many states have rules for home improvement contracts and deposits. Some towns require a permit for replacements, especially for egress windows. Our general contractor licensing guide covers each state.
3. Follow the lead rule on older homes
The EPA's lead rule applies to work in houses, apartments and child-occupied facilities built before 1978, and to contractors who disturb painted surfaces there. Old window frames and sashes are painted surfaces. Get your firm certified and follow the work practices if you replace windows in older homes. On second-story openings, OSHA requires fall protection at six feet in construction.
4. Register the business and set up taxes
The SBA lists the launch steps in this order: pick a location, choose a structure, choose a name, register, get federal and state tax ID numbers, apply for licenses and permits, open a business bank account, and get insurance. For a window and door installation business working out of a truck, the location is usually your home address and the area you will serve.
- Structure. A sole proprietorship is the simplest. An LLC keeps the business separate on paper. Ask an accountant which fits your state and your plans.
- Tax ID. The IRS gives out an employer identification number (EIN) online, and says you never have to pay a fee for one. Websites that charge for an EIN are not the IRS.
- Self-employment tax. The IRS lists the self-employment tax rate as 15.3%: 12.4% for Social Security and 2.9% for Medicare. Income tax comes on top, so set money aside from every job.
- Bank account. Open it before the first payment lands, so every dollar in and out is easy to find at tax time.
5. Pick a name customers can say and find
Your name goes on the truck, the invoices, the Google profile and the yard signs, so pick it once. The free windows and doors name generator gives 36 ideas for your town and style, each with a domain idea, and lists the checks to run before you commit: your state's business name search, a federal trademark search and the domain itself.
6. Get insured before the first job
The SBA describes general liability insurance as cover for financial loss from bodily injury, property damage, medical expenses and defending lawsuits. It says businesses with employees are required to carry workers' compensation, unemployment and disability insurance, and some states ask for more.
Claims come from leaks after the first storm, broken glass and damage carrying units through a house. Ask your agent about general liability with completed work, commercial auto, and workers' compensation once you hire.
7. Gear up and add up your startup costs
No total here on purpose. What you spend depends on what you already own, new or used, and how much work you plan to take on. Price your own list with a local supplier, then put the numbers in the startup cost table of the free business plan generator, which adds them up for you.
- Pry bars, oscillating tool, reciprocating saw and a miter saw
- Levels, shims, flashing tape and low-expansion foam
- Caulk guns and sealants rated for exterior use
- Glass suction cups and a dolly for heavy units
- Ladders and a way to work safely on second-floor openings
Tools are a small part of the startup cost. Supplier credit and cash to carry orders between deposit and final payment are the larger part.
8. Set your prices
Price per opening: supplier cost with markup, install hours, trim and sealant, disposal and permits. Our guide to pricing window and door installation has a worked ten-window example, and the free window glass replacement cost calculator covers glass-only repairs.
9. Find your first customers
- Siding and roofing contractors. Their customers ask about windows.
- The neighbors. Koira mails nearby homes after each job.
- Homeowners who want options. Good, better and best on one page make the choice easy.
- Lumberyards and showrooms. They need installers for what they sell.
10. Get paid and keep the customer
Take a deposit at signing to cover the order, offer pay over time on whole-house jobs, and collect the balance on install day with pay at the door.
11. Grow past one truck
Your second installer lets you set heavy units safely and finish a house in a day. Read how window and door installers run on Koira.
Sources
- SBA: Launch your business (the launch steps), checked October 8, 2026
- SBA: Get business insurance, checked October 8, 2026
- IRS: Get an employer identification number, checked October 8, 2026
- IRS: Self-employment tax (Social Security and Medicare taxes), checked October 8, 2026
- EPA: Renovation, Repair and Painting Program, contractors, checked October 8, 2026
- OSHA: Fall protection, checked October 8, 2026
Last checked October 8, 2026. This page is general information, not legal or tax advice. Rules change and differ by state and city, so confirm with the agency named before you act.