Window replacement in existing frames

Retrofit versus new construction

There are two ways to replace a window. A new-construction window has a nailing fin that sits under the siding or stucco, so the old window comes out with a strip of wall around it. A retrofit window, often called a replacement or insert window, has a flat flange or fits inside the existing frame, so the stucco stays put.

Most homes in the San Gabriel Valley have stucco walls, and retrofit windows are the usual way to replace their aluminum sliders without cutting the exterior. That is the work we do.

Changing the size of an opening, adding a window, or replacing a window where the frame or framing is rotted is outside our scope. We will tell you which one fits after we see photos.

Measuring

Retrofit windows are ordered to size, so measurement is the step that matters. We measure width at the top, middle and bottom, height at both sides and the center, and check the diagonals for square. The smallest numbers set the order size, minus a small gap for shims and sealant. Arrival depends on the order, so we schedule the install once they are in hand.

What to look for in a new window

• Dual-pane glass with a low-E coating cuts heat gain on sunny walls.
• NFRC label: new windows carry a label from the National Fenestration Rating Council showing U-factor and solar heat gain. Lower numbers mean better insulation and less sun heat.
• Frame material: vinyl is common and affordable; fiberglass and aluminum-clad options cost more.
• Tempered glass where codes call for it, such as near doors, tubs and low to the floor. Window makers mark tempered panes with a small etched stamp in a corner.

The install

1. Remove the old sash and glass panels.
2. Clean the old frame and check it for rot or damage.
3. Dry-fit the new window, shim it level, plumb and square.
4. Fasten through the frame into the opening.
5. Fill gaps with low-expansion foam and seal the exterior with a bead of sealant.
6. Trim the inside and check that the sashes slide and lock.

Protecting the room

Before an old window comes out, we move furniture back from the wall, lay drop cloths from the window to the door, and tape plastic over shelves and electronics nearby. Old aluminum frames shed grit and sealant crumbs when they are cut free, so we vacuum as we go rather than at the end.

Blinds and curtain rods come down and are set aside labeled by window. When the new window is in, we rehang them, wipe the sill and glass, and walk the room with you before moving on to the next one.

Repair before replacing

Not every window needs to go. Sliders that will not slide often need new rollers and a clean track. Single-hung windows that will not stay up need new balances.

Broken latches, cracked handles and worn pile seals are cheap parts. A single broken pane in an old frame can be reglazed by a glass shop. When repair costs approach a large share of a new window, we will say so.

Sound and dust

Dual-pane windows cut street noise as well as heat, which helps on busy streets near the freeways. A tight new window also keeps out the fine dust that blows in during windy weeks.

Choosing the style

Sliders are the most common style in valley homes and the easiest to replace in kind. Single-hung windows slide up and suit bedrooms. Casement windows crank out and seal tight, but need room to open outside.

Picture windows do not open. We help you choose based on how you use the room, the furniture near the window, and how it opens to the yard.

Window coverings

New windows can be a slightly different depth from the old ones. If you have blinds mounted inside the frame, we check that they still fit. If they do not, we can rehang them as outside mounts.

Bedroom windows

Bedroom windows also serve as an exit in an emergency. A replacement window should open at least as wide as the old one, and we do not swap an opening window for a fixed one in a bedroom.

Timeline

After measuring, we order the windows; how long they take to arrive depends on the order, and we tell you once we know. Install day goes window by window, so each room is open only for a short time. We cover floors and furniture near the work and clean up as we go. Old windows are hauled away.

Questions to ask before ordering

Ask about the frame color inside and out, the grid pattern if you want one, the type of glass coating, the screen mesh, and which way each slider opens. Getting these right on the order avoids a wait for a reorder later.

Clean edges inside

New interior trim or caulk lines finish the opening so there is no gap.

Paperwork to keep

Keep the window order, the NFRC labels from each window and the receipt in your house file. They show the specs of what was installed, which helps when you sell or when a window needs a part later. We leave the labels on the glass until you have photographed them.