San Francisco homes face unique window challenges. Fog, salt air, microclimates, and street noise wear down seals and frames. On top of that, new 2026 energy rules change what passes code. Many homeowners now ask a clear question: repair or replace. The right call protects comfort, preserves character, and keeps permits on track.
This article gives a practical path to decide. It blends code facts with field judgment from hundreds of Bay Area projects. It also explains how Best Exteriors handles energy compliance, SF Planning, and historic restoration so homeowners can move forward with confidence.
Why homeowners are rethinking windows in 2026
The California Energy Code update takes effect for San Francisco permits issued on or after Jan 1, 2026. Most standard double-pane units fall short. For many homes, triple-pane or high-performance “specialized double-pane” becomes the baseline to hit a U-Factor of 0.24 or lower. That shift changes the math on repair versus replacement. It also boosts interest in sound control, trusted window replacement contractor since added glass layers help with both energy and noise.
San Francisco’s housing stock is varied. Pacific Heights has landmark wood windows with ogee details. SoMa lofts face busy streets and need strong STC ratings. Noe Valley and the Sunset deal with fog and condensation. Each home needs a solution that respects these realities.
Quick read: when repair works, and when replacement saves more
Small, isolated issues call for repair. Widespread failure or poor performance points to replacement. A short rule of thumb helps set expectations:
- Repair makes sense if sashes still operate square, wood is mostly solid, and the IGU seal is intact on most units. Glazing putty, weatherstripping, and hardware service can add 5 to 10 years. Replacement makes sense if many seals have blown, frames are rotted or warped, or windows stick and leak. The 2026 U-Factor requirement often tips the scale toward full replacement, since energy payback and resale value improve together.
Code and compliance: what changes in 2026
San Francisco uses the 2025 California Energy Code starting Jan 1, 2026. For residential permits, the rules require tighter window performance than past cycles. Best Exteriors aligns each project with Climate Zone 3 criteria and local review.
Meeting the new 2026 San Francisco energy standards
The Department of Building Inspection will look for the following on submittals and at inspection:
U-Factor ≤ 0.24. This is the headline number for thermal insulation in most projects. Many off-the-shelf double-pane units cannot hit 0.24. Triple-pane or specialized, high-performance double-pane systems often achieve 0.22 to 0.24.
Solar Heat Gain Coefficient limits. Products must match Title 24 prescriptive values for Climate Zone 3 to avoid modeling delays.
NFRC ratings. Windows must carry valid NFRC labels that confirm U-Factor, SHGC, and VT. Field labels must match plans.
Sound control near transit. Homes near Muni lines or 101/280 benefit from STC-rated units. Thicker IGUs, laminated lites, and asymmetric builds raise STC ratings without hurting U-Factor.
Best Exteriors provides Title 24 documentation, NFRC sheets, and product specs that match permit drawings. The team tracks U-Factor at or below 0.24 and confirms SHGC and VT values so DBI signoff moves smoothly.
Historic character and street-facing rules
San Francisco Planning reviews many window projects under Article 10 for landmarks and Article 11 for conservation districts. Visibility from the street matters. The review focuses on operation, sightlines, and finish.
Historic character meets modern efficiency
Planners often require that street-facing windows match the original operation and profile. That means double-hung where double-hung existed, true or simulated divided lites that match the pattern, and historically accurate exterior profiles, such as ogee lugs on Victorian sashes. In-kind wood replacement remains the standard for Category A Landmarks. Best Exteriors works with custom millwork shops to match rail and stile widths and sill horns.
For non-historic buildings, the May 2025 material relaxation helps. Owners are no longer strictly forced to use wood in many cases. Fibrex and fiberglass options can pass review if street-facing profiles match the existing look. Inside yards or non-visible elevations allow more flexibility, including thermally broken aluminum on modern homes.
Simulated Divided Lites with spacer bars offer the historic grid look while using insulated glass. Proper SDL bar width and placement preserve proportion. Low-E4 glass with argon or krypton fills increases performance. Wood-clad or wood interiors meet preservation goals in Pacific Heights, Alamo Square, Russian Hill, and Presidio Heights. For mid-century homes and Diamond Heights, clean-line fiberglass frames often fit the era and pass review faster.
Repair scenarios: extend life without losing character
Some windows should be repaired, not replaced. On painted ladies near Alamo Square, original old-growth redwood often outlasts modern softwoods. If the frames are sound, Best Exteriors can restore function and weather resistance.
Typical repair scope includes glass re-glazing, sash cord replacement, bronze weatherstripping, and sill slope adjustments to shed water. For drafts, spring bronze or silicone compression seals cut leakage without changing appearance. In many homes, this work reduces heat loss and noise enough to hold off full replacement for several years.
However, repair will not change the U-Factor label for a permit. If a permitted project triggers energy documentation, the city will expect NFRC-rated units. For low-scope repairs without a permit, careful restoration is a good bridge.
Replacement scenarios: code, comfort, and long-term value
If condensation forms between panes, seals have failed. If sashes swell and stick, humidity and racking may have warped the wood. If putty crumbles and the rails feel soft, rot has spread. In these cases, replacement delivers better function and meets 2026 code.
Best Exteriors specifies products by neighborhood needs:
- Pacific Heights and Presidio Heights: Marvin Ultimate series or Jeld-Wen Custom Wood with U-Factors around 0.22 to 0.24, custom exterior profiles, and SDLs that match historic patterns. Noe Valley and The Castro: Fiberglass or Fibrex frames for low maintenance and stable performance in foggy pockets, with laminated glass options for better STC. SoMa and Mission corridors: European tilt-and-turn or thermally broken frames with triple-pane IGUs, asymmetric glazing for higher STC, and factory finishes that withstand urban grime. Russian Hill and Alamo Square: Wood-clad or all-wood with ogee lugs and putty-line sightlines that match original sashes, combined with Low-E coatings that avoid a mirror look.
In every case, the team selects Low-E coatings that keep natural light. SHGC choices vary by facade orientation to reduce glare in west-facing rooms while keeping morning sun comfort.
Noise control for city blocks
Street noise is real in San Francisco. Buses, scooters, and weekend traffic create a steady hum. If noise interrupts sleep or work, sound-focused glazing helps. Triple-pane is strong, but the key is different glass thicknesses and laminated lites to break up sound waves. An STC 34 to 40 window can turn a busy street into a manageable backdrop. Frames matter too. Thermally broken frames reduce both thermal bridging and vibration paths.
Product brands that fit SF homes
Best Exteriors installs across a wide brand set so each home gets the right spec. For historic and premium wood, Marvin Ultimate, Pella Reserve, Jeld-Wen Custom Wood, and Loewen cover most profiles. For steel accents and modern statements, Brombal offers thin sightlines with thermal breaks. For strong value in fiberglass and vinyl, Milgard Ultra and Tuscany work well in many mid-century and newer builds. European tilt-and-turn systems deliver airtight seals and deep frames for triple-pane glass.
The company matches products to target U-Factors and SHGC values, then confirms NFRC data for submittals.
Permits, planning, and paperwork without the headaches
Replacing windows in San Francisco involves more than ordering units. Planning, CEQA, and DBI all have a say. Best Exteriors runs a white-glove permit process that keeps projects moving.
Our SF Planning and permit service
Window window replacement contractor projects that affect street-visible elevations often need an Administrative Certificate of Appropriateness. Best Exteriors prepares elevations, section details, and product cut sheets that show operation, muntin patterns, and exterior profiles. For projects in conservation districts, the team coordinates Article 11 review. If CEQA applies, the firm assembles required documentation to avoid surprises.
On the energy side, the team produces Title 24 forms and NFRC labels for final inspection. The company’s Title 24 energy analysts confirm U-Factor and SHGC inputs so inspectors have clean files.
Costs, payback, and what to expect
Repair is less expensive upfront. It suits single rooms, scattered failures, or owners planning to sell soon without a heavy permit scope. Replacement costs more, but the 2026 U-Factor threshold clamps down on partial measures. With energy rates in San Francisco, high-performance windows can trim heating use in fog belts and improve cooling control in sunnier pockets. The comfort gain is often immediate. Resale value can rise when buyers see new, code-ready windows with transferable warranties.
On historic homes, custom millwork and SDL patterns increase cost. That said, approved profiles protect curb appeal and help projects pass Planning, which saves time and re-application fees.
Materials and parts that drive performance
Insulated Glass Units with argon or krypton gas reduce heat transfer. Low-E4 coatings tune solar gain and glare. Thermally broken frames cut condensation and raise interior surface temperatures, which feels more comfortable in foggy weather. For historic looks, Simulated Divided Lites with spacer bars avoid a flat, fake appearance. For Victorian restorations, wood-clad frames keep exterior durability while preserving warm wood interiors.
Details like sill pans, back dams, and proper flashing guard against leaks. In San Francisco’s wind-driven rain, installation quality matters as much as the product. Best Exteriors uses AAMA methods, checks plumb and square, and shims hardware points to prevent sash bind.
Repair or replace: a simple homeowner checklist
Use this quick pass before calling for bids:
- Are more than two windows fogged or showing failed seals? Do sashes stick, wobble, or rattle even after basic tune-ups? Is the home in a review district where visible elevations must match originals? Is a permit required that will trigger Title 24 documentation? Do outside noise and drafts affect sleep or work?
If more than two answers are yes, a full replacement evaluation likely makes sense. If most answers are no, targeted repair could be a smart holdover.
Why homeowners choose Best Exteriors
The company focuses on energy codes and preservation, not just measurements and orders. It is a Lead-Safe Certified Firm and Diamond Certified. The team includes SF Planning permit specialists and Title 24 energy analysts. For historic streets, Best Exteriors works with custom millwork to match profiles. For modern builds, it installs high-performance triple-pane and STC-rated systems. The goal is simple: pass review, pass inspection, and deliver quiet, comfortable rooms that look right for the block.
For homes in Pacific Heights, the team often specifies Marvin Ultimate wood windows at a U-Factor of about 0.22, preserving historic integrity and exceeding the 2026 standard. For condos along 101 or 280, thicker IGUs and laminated glass push STC ratings higher without sacrificing thermal goals.
Service areas and local insight
Best Exteriors serves the 7x7 across 94102, 94103, 94107, 94109, 94110, 94114, 94117, 94118, 94123, and 94127. The company understands Article 10 and 11 rules for landmarks and conservation districts. It has experience near signature sites like the Painted Ladies, Coit Tower adjacency, and Mission District Victorian clusters. This local knowledge shortens the path from first visit to final signoff.
Ready for a clear plan?
Homeowners do not need to guess. Best Exteriors offers a free code-compliance audit and a clear, line-item plan for repair or replacement. For home window replacement San Francisco projects that must meet a U-Factor of 0.24 or better, the team brings the right products and paperwork. For historic windows, it restores character with the profiles and finishes Planning wants to see. For noise along busy corridors, it installs STC-rated solutions that make rooms calm again.
Book a consultation, review options by room, and see exact numbers before work starts. Call +1 510-616-3180 or visit https://bestexteriors.com. Find reviews on Yelp and social updates on Facebook and Instagram. For map directions, use the company’s Google Maps listing.
Best Exteriors handles the details so San Francisco homeowners can enjoy quiet rooms, lower bills, and windows that pass both code and curb appeal.
Best Exteriors
California, 94612, United States
Phone: +1 510-616-3180
Website: https://bestexteriors.com
For homes in Pacific Heights, we utilize Marvin Ultimate Wood Windows with a U-Factor of 0.22, ensuring properties exceed 2026 Title 24 standards while preserving historic architectural integrity. Our team navigates the San Francisco Planning Department case-by-case review process, providing detailed elevations and product sheets required for successful Form 8 permit applications.
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