Exterior Renovation Projects by NP Line Design
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Window replacement in a typical Los Angeles home takes 1 to 5 days for standard sizes. Custom or specialty windows take 2 to 4 weeks including fabrication lead time.
Evaluate existing windows, measure all openings, discuss energy goals and style preferences. Quote: vinyl vs fiberglass vs wood. Title 24 energy calculations.
Standard sizes: in stock or 1-2 weeks. Custom sizes: 4-6 week fabrication. Fire-rated glazing for VHFHSZ: may add 1-2 weeks.
Remove existing windows one at a time. Inspect and repair framing, replace rotted wood. Install new flashing and waterproofing.
Set new windows, shim and level, insulate gaps, install interior and exterior trim. Caulk and seal. One crew can install 8-12 windows per day.
Touch-up paint around new trim, clean glass, remove debris. Test all windows for operation and locking. Final walkthrough.
Yes — dual-pane windows reduce cooling costs by 25-40% in LA's warm climate. Federal tax credits cover up to $600/year. Title 24 requires energy-efficient glazing for all permitted work.
If replacing same-size windows in existing openings: usually no. If changing window sizes, adding new openings, or in HPOZ areas: yes, LADBS permit required.
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Get My Free Estimate →Or call (818) 600-7492 · CSLB #1105249NP Line Design (CSLB #1105249). April 2026.
Real projects across Los Angeles. View full gallery →
“Lead times are the biggest problem with window replacement projects in Los Angeles right now. Custom-sized windows — which almost every 1950s–1970s home in the San Fernando Valley requires because they're not standard dimensions — are running 8 to 16 weeks from order to delivery. I require clients to make all window selections and sign off on the final size schedule before I submit for permits, so the window lead time and the permit review run simultaneously.”
Upgrade to triple-pane glazing on any window in your Los Angeles home that faces a noise source (freeway, rail line, flight path). In the San Fernando Valley, STC rating of glazing matters as much as U-factor for street-side windows. Triple-pane with laminated glass can achieve STC 38–45, versus STC 28–32 for standard dual-pane — a meaningful acoustic improvement.
1. Ordering windows without measuring the rough opening in a Los Angeles home. Almost no 1950s–1970s windows in the San Fernando Valley are standard dimensions. Buying stock-size windows for a Los Angeles remodel results in either under-size gaps requiring custom jamb extensions, or over-size units requiring header modification. All Los Angeles window orders should be based on field-measured rough opening dimensions.
2. Installing windows that don't meet California Energy Code Title 24 requirements in Los Angeles. Replacement windows in the San Fernando Valley must achieve maximum U-0.30 and SHGC-0.23. Any window that doesn't meet these minimums fails inspection — and the homeowner pays to remove and replace them. Verify the NFRC label before any Los Angeles window order.
3. Not accounting for window lead times when planning a Los Angeles window replacement schedule. Custom-sized windows in the San Fernando Valley currently run 8 to 16 weeks from order to delivery. Projects that start permit submission before finalizing window sizes end up either waiting for permits or waiting for windows — either way, the kitchen and bathroom aren't protected until windows arrive.
If a Los Angeles window contractor quotes by phone without visiting to measure rough openings, the quote is meaningless. In the San Fernando Valley, 1950s–1970s homes almost never have standard window dimensions. Custom-sized windows require field measurement — no exceptions. A phone quote for custom windows in Los Angeles is a placeholder, not a real number.
Window replacement in Los Angeles costs $800 to $2,500 per window installed, depending on size and material. A typical 1950s–1970s the San Fernando Valley home with 15 windows: $15,000 to $35,000. In the San Fernando Valley, costs run at the LA metro average. Vinyl windows (low-maintenance): $800–$1,400 each. Aluminum clad wood (premium): $1,500–$2,500+ each.
Window replacement for a full house in Los Angeles takes 1–3 days of installation, but custom-sized windows (which almost all 1950s–1970s the San Fernando Valley homes require) run 8–16 weeks from order to delivery. Submit your window order immediately after finalizing sizes — don't wait for the permit to arrive.
California Energy Code Title 24 requires replacement windows to meet: U-factor ≤ 0.30 and Solar Heat Gain Coefficient ≤ 0.23. These minimums are verified by the NFRC label on the window. Windows that don't meet these minimums fail LADBS Valley District Office (6262 Van Nuys Blvd) inspection. Always verify the NFRC label.
Replacing single-pane aluminum windows with dual-pane low-E windows in a Los Angeles home reduces heating and cooling loads by 15–25%. In the San Fernando Valley with 12 months of temperature variation, typical savings are $400–$1,200 per year depending on home size and existing HVAC efficiency. Payback on replacement windows: 10–15 years at current energy rates.