A Penhallow company - serving Orange County, CA
A new rear addition with a vaulted beamed ceiling and tall windows

PGT Home Additions & ADU Nationwide

Free Estimate on SiteCalls Answered by a Live Person, 24/7Background-Checked TechniciansA Local Team in Orange County
A second-story addition that matches the existing roofline
A wide opening with a new beam where the kitchen wall was removed
A remodeled hall bathroom with subway tile and a floating vanity
A remodeled primary suite with built-in wardrobes and a window seat
New painted shaker cabinets with an organized deep drawer
A remodeled hall bathroom with patterned floor tile and painted walls
A remodeled staircase with wood treads and a slim metal railing
A small remodeled galley kitchen with cabinets to the ceiling
Every visit starts with

Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled

Your dream remodel for as low as$199/month*On approved credit; ask for current terms
Get your free estimate

PGT Home Additions & ADU: The Orange County Owner’s Guide

PGT home additions and ADU construction in Orange County typically runs $45,000 – $130,000 for a full addition and $90,000 – $220,000 for a detached ADU, depending on square footage, foundation work, and finish level. Most Orange County homeowners call us after realizing the PGT windows and doors they’re adding are the easy part, but the structural planning, permitting, and integration with the existing roofline are where projects stall. We walk you through the entire scope with a written price before any work starts, so you know exactly what the addition costs before a hammer swings.

Call (424) 541-1701

What we see most often: a homeowner has PGT impact windows or a sliding glass door picked out for their new sunroom or ADU, and they need a contractor who can frame the addition, tie the new roof into the existing structure, and install those PGT products correctly. That’s the work we do. Penhallow Remodeling Orange County is an independent general contractor, not affiliated with PGT, but we install their windows and doors as part of larger addition and ADU projects throughout Orange County.

Which PGT Models This Applies To

A garage converted into a guest room and home office

PGT’s product lines that show up most often in Orange County additions and ADUs are the WinGuard and SpectraGuard impact-rated window and door series, along with their standard aluminum and vinyl lines. WinGuard carries the Miami-Dade and Florida Building Code ratings that many Orange County coastal and hillside properties need for wind-borne debris protection, especially in Huntington Beach, Newport Beach, Laguna Beach, and the canyon areas of Anaheim Hills where fire and wind exposure drive building requirements. SpectraGuard is the vinyl option that fits tighter budget additions without sacrificing impact ratings.

Before you order windows for an addition, check the label on the frame or sash: PGT prints the series name, glass type, and manufacturing date right on the sticker between the glass panes. That sticker matters because it tells us whether your existing windows are WinGuard, SpectraGuard, or standard builder-grade PGT, which determines whether we match new units to what you already have or upgrade to meet current Orange County wind load requirements. The compatibility gotcha we see on additions: mixing impact-rated and non-impact windows in the same wall assembly can void the wind mitigation credits your homeowner’s insurance carrier may be counting on. We verify the series before we write a single number.

For ADUs, the decision tree is simpler but still specific. Most Orange County cities, including Irvine, Costa Mesa, and Fullerton, require new ADUs to meet current Title 24 energy standards. PGT’s SunGuard and EcoView lines meet those standards, but not every PGT window does. We check the National Fenestration Rating Council label (the NFRC sticker on the corner of the glass) to confirm U-factor and solar heat gain coefficient before we spec anything. That’s the difference between passing final inspection the first time and re-ordering glass because the energy sheet didn’t pencil out.

When it comes to OEM versus aftermarket, for PGT windows specifically we recommend OEM or PGT-authorized replacement sashes and glass packages. The interlocks, weep systems, and corner joinery on PGT frames are proprietary enough that generic replacement parts create air and water leaks within a year or two. For non-structural components like weather stripping, screens, and hardware, quality aftermarket equivalents from suppliers who spec to PGT’s dimensions work fine and cost 20 – 40% less. We stock KraftMaid, Cambria, and Silestone materials for the interior side of additions, but PGT glass stays PGT.

Explore

Styles & brands we work with

Kitchen remodeling
Kitchen remodeling
Bathroom remodeling
Bathroom remodeling
Home additions & ADU
Home additions & ADU
Roofing
Roofing
Windows & doors
Windows & doors
Driveway & pavers
Driveway & pavers
Fence
Fence

Signs Your PGT Home Additions & ADU Is Failing

  • Condensation between the glass panes. The desiccant strip inside the sealed unit has saturated, which means the inert gas fill has leaked out. The window still functions, but the insulating value is gone. In Orange County’s marine layer climate, this shows up first on west-facing windows in coastal communities like San Clemente and Dana Point.
  • Water staining on interior drywall below a PGT window or door. This usually means the window’s weep holes are clogged or the exterior flashing around the rough opening wasn’t installed to PGT’s spec. We see this frequently on additions where the window was installed before the exterior stucco was fully cured, breaking the sealant bond.
  • Sliding door binds or drags after rain. PGT sliding glass doors are heavy, often 200+ pounds for a 6-foot panel. When the frame shifts even a fraction, the rollers wear unevenly and the door drags. On second-story additions in areas with expansive soil, like Yorba Linda or parts of Mission Viejo, that frame movement is a structural issue, not just a hardware problem.
  • Hinge-side sag on an outswing PGT door. The stainless steel hinges PGT uses are rated for the door weight, but if the rough opening wasn’t shimmed correctly, the hinge screws tear out of the jamb. This is an installation defect, not a product defect, and it means the door has to be pulled and re-hung.
  • Visible sealant cracking around the exterior perimeter. PGT specs specific sealant types (typically a high-quality polyurethane or silicone hybrid, never painter’s caulk) for their frames. When the wrong sealant was used, it hardens and pulls away from the aluminum or vinyl within two or three Orange County summers. Once that seal fails, water finds the rough opening.
Before & after

See the difference

Before - Recent ProjectBeforeAfter - Recent ProjectAfter
Recent Project
Before - Full RestorationBeforeAfter - Full RestorationAfter
Full Restoration
Before - Complete UpgradeBeforeAfter - Complete UpgradeAfter
Complete Upgrade

Replacement Cost & What’s Included

A finished backyard cottage with a small covered porch

Here’s what full PGT home additions and ADU projects cost in Orange County, written plainly:

  • Home Addition (full build): $45,000 – $130,000 – This covers a 200 – 600 square foot addition with foundation, framing, roofing tie-in, stucco or siding, drywall, electrical, and PGT windows and doors. The spread depends on whether you’re adding a simple single-room bump-out or a full primary suite with a bathroom.
  • ADU Construction (detached): $90,000 – $220,000 – A 400 – 1,200 square foot detached ADU with separate utility connections, kitchen, bath, and PGT glass. City fees, utility tap fees, and site work drive this range more than anything else.
  • Garage Conversion: $30,000 – $80,000 – Converting an existing garage to living space with PGT windows and a new entry system. Existing slab condition and whether the garage shares a wall with the house affect the final number.

Every one of these projects includes a written price before we start, not a verbal estimate. That written price includes the PGT materials, all labor, permit-ready plans, and the 365-Day Done Right Promise in writing. If something fails inside the guarantee period, we come back and fix it at no charge. That’s the Kingswell Way, and we’ve been operating to it since 2004. Your number on day one is your number on the invoice.

DIY or Call Us?

Here’s the honest split. You can safely check your PGT windows yourself: look for condensation between panes, press on the glass to see if the seal flexes, and inspect the exterior sealant bead. That’s diagnostic, and it helps you understand what you’re dealing with before you call anyone.

What you shouldn’t DIY is anything involving window removal, especially on an addition. A PGT impact window panel can weigh 80 – 150 pounds. If it drops on a sloped roof or a second-story opening, someone gets hurt. Adding an ADU means structural work, electrical, plumbing, and permitting. We’ve also seen what happens when a homeowner flashes a PGT window incorrectly: the water damage is silent for two years, and then the drywall is moldy. Trevor Nash grew up in the San Gabriel Valley and learned construction at Los Angeles Trade-Technical College, and he’ll tell you the same thing he tells every Orange County homeowner: give me the number first, then pick up the tool. Call (424) 541-1701 and we’ll look at your PGT windows as part of the bigger addition picture, no charge for the estimate.

FAQs

A single-story rear room addition with tall windows and a new patio

Getting started with Penhallow in Orange County

Every project starts with a conversation and a written price. Here is how to take the first step.

A project lead measuring a kitchen with the homeowner during a free estimate

Free on-site estimate

A project lead walks the job with you, measures it and hands you a written, line-item price. No obligation.

Book an estimate
A remodeling crew arriving at a home with lumber and tools

Your Orange County team

A local crew that works across Orange County and the towns around it, to the same written standard as every Penhallow location.

Areas we serve
A worker laying floor protection and a dust barrier before work starts

Read our written promise

What we promise on every job, written down, with the terms spelled out before any work starts.

Our promise
Need Construction help in Orange County? Licensed & insured · Free on-site estimates response · free estimates
Call (424) 541-1701
Local Service Coverage

Request a Free Estimate in Orange County

Tell us what you need - Penhallow Remodeling Orange County responds fast. No obligation.

By providing your information above, you confirm you have read our Privacy Policy and agree that you may be contacted via phone, email, or SMS about your request, including by the independent contractors we may refer it to.

Prefer to text? Text Us
Call Now - 24/7 Dispatch