Different types of windows fit different houses. New Construction and replacement windows are such that they differ significantly from each other.
Key Takeaways
- New construction windows include a nailing fin for installation in new homes, while replacement windows fit into existing window openings.
- Replacement windows are ideal for home renovations and updates, whereas new-construction windows are used in newly built homes.
- Installation of replacement windows is faster and less intrusive than new construction windows.
New Construction vs Replacement Windows
New construction windows are installed during the construction of a new home or addition. They are designed to be installed directly into the framing of the house. Replacement windows are windows that are used to replace existing windows in a home renovation project. They are designed to fit into the existing window frame.

These new construction windows are easily available and in stock in the majority of home centres. When repairing old structures that have been badly damaged, new construction windows are employed.
Replacement windows are employed in areas when the marginal area is in good condition, and there is an existing window in the structure or residence.
Comparison Table
Parameters of Comparison | New Construction | Replacement Windows |
---|---|---|
Definition | Used for transparent and clear openings, with no siding in place or trim in the house. | Windows that replace the existing replacement windows or new construction windows. |
How to identify? | Attachment fins, flanges or nailing on the outer side of these types of windows. | Do not possess any flanges or nailing fins, characterized by the smooth side. |
Installation process | Moderately easy (aftermath work needed is difficult.) | Too tricky as it exerts tolerances. |
Availability | Available readily and mostly in stock in home centres. | A bit tough to find, obtained from online platforms. |
Use | At the time of repair of existing old and damaged structures. | The marginal area possesses a good shape, and the structure has an existing window. |
Performance | It perfectly resists the weather. | Nailing fins are absent, weather-tight. |
Cross-over | When structures deteriorate badly. | In the newly constructed area, no need to fix a replacement window. |
What is New Construction?
New-construction windows are utilised in houses with no cladding or trim for translucent and clear openings. Because new-construction windows have attachment fins, flanges, or nails on the outside, they may be detected and identified.
The installation of new-construction windows is reasonably simple, but the follow-up work is challenging. These new construction windows are readily available and mostly in stock in the majority of home centres.
When repairing old structures that have been severely damaged, new construction windows are employed. They are also employed in the construction of new constructions.
When new building windows are fitted appropriately, they can withstand the elements effectively. When a house’s frame and walls begin to decay, it’s time to consider new construction windows.

What is Replacement Windows?
Replacement Windows are windows that replace existing replacement windows or new construction windows. There are no flanges or nailing fins on replacement windows.
Replacement window installation is difficult because tolerances are required. Replacement windows can be difficult to come by, but they can be found on the internet.
Replacement windows do not have nailing fins, which makes them better. They can also withstand the elements or are weatherproof.

Main Differences Between New Construction and Replacement Windows
- When new construction windows are correctly installed, they can perfectly resist the weather. On the other hand, nailing fins are absent in the case of replacement windows which makes them better.
- When both the frame and the walls of a house deteriorate badly, then it’s high time when the demand for new-construction windows occurs.
