Replacement windows installed on a Greater Portland, Maine home

Window Replacement in Cumberland County, Maine

Window replacement in Cumberland County, Maine: vinyl and wood-clad units from Andersen, Marvin, Pella and Integrity, flashed and sealed. Free estimates.

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How window replacement actually goes together

Every window replacement job is built in a specific order, and the layers you never see once the job is finished are what actually keep water out of the wall or roof. The diagram walks through it step by step.

New Andersen replacement window installed on a Back Cove home

How a Window Rough Opening Gets Flashed

  1. Sill pan — sloped, with dammed ends, so any water that gets past the window drains out, not into the wall
  2. Window unit — set directly on the sill pan before the sides are fastened
  3. Jamb flashing tape — laps over the sill pan on both sides, in the order water will travel
  4. Head flashing — tucks under the weather-resistive barrier above the opening
  5. Drainage — every layer sheds down and out, never behind the one below it

About window replacement

A new window is only as good as the way it is set into the wall. Replacement windows go in either as inserts inside the existing frame or as full-frame units after the old frame comes out; the right choice depends on the condition of the frame, the trim you want to keep, and the siding around it. The site lists vinyl replacement windows and wood or clad units from Andersen, Marvin, Pella and Integrity, in double-hung, casement, picture, bay, sliding and awning styles.

This page is part of our window replacement work, which lists typical price ranges and materials. Other related services: bay and picture windows, siding replacement, vinyl siding installation, roof replacement.

What the job involves

  • Each opening is measured and checked for rot in the sill, jambs and framing.
  • Old sashes or whole frames come out; damaged wood is repaired before the new unit goes in.
  • Units are set level, plumb and square, shimmed, and fastened as the manufacturer requires.
  • Low-expansion foam and backer rod seal the gap without bowing the frame.
  • Flashing, exterior trim or capping and interior casing are finished so the opening sheds water.

Signs it is time

  • Fog or condensation between the panes of insulated glass
  • Sashes that stick, will not stay up, or let in drafts
  • Soft or rotted sills and frames
  • Single-pane glass or storm windows you take on and off every year
  • Frost or ice on the inside of the glass in winter

What affects the price

  • Number of windows, their sizes, and any custom shapes
  • Vinyl versus wood or clad units, and the brand and series
  • Insert versus full-frame replacement
  • Glass package and grille options
  • Interior and exterior trim work, and whether siding is open around the opening

Every job is priced from a free on-site estimate, with a fixed-price written proposal before work starts.

Homeowner Guide

Window Replacement: U-Factor, ENERGY STAR, and Full-Frame vs. Insert in Maine

Two windows can look identical and perform very differently in a Maine winter. The number that actually predicts how much heat a window loses is its U-factor, and Maine falls in ENERGY STAR's coldest (Northern) climate zone, which sets its own bar for that number. The other decision that matters as much as the window itself is whether the job is a full-frame replacement or an insert (pocket) replacement — they solve different problems.

ENERGY STAR's Northern Climate Zone

ENERGY STAR's Northern zone criteria for windows (verify current figures at energystar.gov before quoting a specific product)
MetricWhat it measuresNorthern zone target
U-factorRate of heat loss through the window — lower is betterMaine's energy code (2021 IECC, Climate Zone 6) allows at most U-0.30; ENERGY STAR's Northern-zone criteria are stricter and were tightened in 2023, so compare the NFRC label on the window itself
SHGC (solar heat gain coefficient)How much solar heat passes through the glassNot restricted in the Northern zone — some solar gain is a benefit in a cold climate
Window replacement in progress on a home near the Eastern Prom

Full-Frame vs. Insert Replacement

An insert (pocket) replacement fits a new window into the existing frame, leaving the exterior trim and interior casing in place. It's faster, less disruptive, and less expensive — the right call when the existing frame is square, dry, and sound.

A full-frame replacement removes the window down to the rough opening, including the old frame and exterior trim. It takes longer and costs more, but it's the only way to fix a rotted sill or frame, correct bad flashing from a previous installation, or change the window's size. If we find rot or water damage once an insert job is opened up, we'll always tell you before going further rather than installing a new window into a compromised opening.

Andersen logo

Andersen Windows

Andersen is one of the manufacturers whose replacement windows we install, across several product tiers from vinyl-clad to their higher-end wood-composite lines. Exact U-factor and SHGC ratings vary by glass package and frame material within each line — we'll pull the specific NFRC label numbers for whatever product you're considering.

Why Flashing Matters As Much As the Window Itself

A high-performance window installed with bad flashing will leak long before its glass or frame ever fails. The sill pan, jamb tape, and head flashing sequence around the opening is what actually keeps water out of the wall — see our window flashing diagram below.

Sources: ENERGY STAR windows, doors and skylights · Andersen Windows products

Brand names and logos are trademarks of their respective owners, shown only to identify the products discussed. Cardinal Exteriors is an independent contractor and is not affiliated with or endorsed by these manufacturers.

Window Replacement: frequently asked questions

Google reviews

What Greater Portland homeowners say

  • Andrew Mountcastle

    May 2026 · Google

    We hired Cardinal Exteriors to reside our house and install all new windows, and it was a terrific experience from start to finish! Bob was one of the very best contractors we've ever worked with (and we've worked with many over the years). He was extremely responsive, helpful, respectful of wishes and concerns, and never pressured us in any way.

  • Steve Kelley

    October 2025 · Google

    Bob @ Cardinal Exteriors replace 26 windows and resided our office building in Westbrook in 2025. Being in the construction business, we understand how proposals sometimes come with change orders and surprises if not outlined up front. Bob and his team finished our job on schedule and actually below budget.

  • John Nueslein

    December 2025 · Google

    CARDINAL EXTERIORS re-shingled my roof. Bob Proved to be Knowledgeable and Trustworthy. He was responsive to my questions and took the time to explain the materials being used and the steps they were taking to weatherproof the roof of my home. The work crew was polite and they cleaned up the job site at the end of each work day.

Get a free window replacement estimate

Tell us about the house and what you want changed. One of the owners will call to set up a visit, measure, and write a fixed-price proposal. No pressure, no obligation.

Need it today?Call Mike (207) 408-5388

or Bob at (207) 252-0759