Window Parts

Window Parts

Returns and Trim refers to the same pieces of millwork as Lining and Casing. The two phrases are synonymous.

Returns – (Or Lining) The return is the piece of wood trim perpendicular to the sash. It follows the width of the wall and can vary in size depending on the width of the wall. This piece is also referred to as the side jamb. Synonyms: returns, lining, side jamb.


Trim – (Or Casing) These pieces are installed flat against the wall and are commonly a decorative shape.

Door Trim - The finishing cost for new doors is the same whether they get new trim or not. New doors almost always get new trim when being replaced. If the existing trim was re-used it will still need a lot of attention with filling new nail holes and touchup. The most common variable for doors is Trim Only for Patio Sliding Doors.

Apron – Bottom piece of trim beneath the windowsill. Included in the price for finishing trim.

Sash – The frame directly surrounding the glass.

Sill – (Or Stool) Horizontal piece at bottom of window, parallel to the floor. Included in the price for finishing trim.

Ogee stop

Ogee Stops – (Or Stops) Frequently when replacing a double hung window the original woodwork can stay in place if the window is installed from the exterior of the home. The only new interior trim pieces of wood are three narrow rectangular pieces called Stops to fill gaps between the new sash and the original trim. A more decorative stop in a more traditional home may come with a rounded off edge in the shape of an S, these are called Ogee Stops.

Divided Lights – We charge for each individual divided light. So you need to count them all. Divided Lights are described in many different ways. Sometimes they are referred to as Real Divided Lights, RDL if they are actual separate individual panes of glass or Simulated Divided Lights, SDL if the sash is in reality one piece of glass but gives the appearance of multiple panes. Some manufacturers call them Full Divided Lights, FDL. For the finisher they are all priced the same if we cannot remove the grid from the sash.

Double hung window

A double hung window with 12 divided lights. Six in the upper sash and 6 in the lower sash.

Grid – (Or Grill) (Snap Out Grid) Frequently grids can be removable. If they are a snap out feature the price is different than a divided light so we need to know if they can be removed. Some grids need to be finished on two sides. Synonyms: grid, grill, grille, window dividers, muntins.

Restoration – If the window needs to be replaced and the trim stays, chances are that this woodwork will need some finish restoration. Water stains on returns and sills are quite common. Restoration refers only to the finish treatment of: repairing dents with filler, sanding, bleaching, staining, glazing, and clear coats, and not millwork replacement. Read More >

More information on Types of Windows and Doors

To make the form smaller and estimating more condensed we combined these three styles of windows as just one type. The price for a Casement window is the same for an Awning or Hopper as they are essentially the same design just oriented differently within the opening. We also combined Double Hung windows with Single Hung windows, as they are so similar.


Casement - A window that is attached to its frame by one or more hinges at the side of the sash frame. They are opened with a hand crank usually above the windowsill and frequently have hand levers for locks on the sides of the frames.


Awning – A window that is attached to its frame by hinges at the top of the sash frame. They are opened by a hand crank and often have a scissoring type of hardware style to hold the window open. They may also have levers that lock the window on the sides of the frame.


Hopper – The least common of the three types, a hopper window will be hinged at the bottom of the sash frame. In-swing hopper windows are commonly found at the tops of doors for added circulation and can be referred to as transom windows. An out-swing hopper window is often used in a basement installation where there is the advantage of increased airflow while keeping out debris. An excellent choice for ventilation in small rooms that do not have a lot of wall space.


Transom – Refers to an architectural cross member or transition bar above the door or window, that separates design elements. A window or light placed above the door is also above the transom frame member. The window can be fixed or operable. Or even a decorative carving that lets light in can be referred to as a transom light.

Picture – A fixed inoperable window.

Double Hung

Double Hung – A window with two sashes that can move vertically past one another within the frame.

Single Hung – A window with one fixed upper sash and one operable lower sash that moves vertically within the frame. Priced the same as a Double Hung.

Glider – A window with two sashes that can move horizontally past one another within a frame. Or have one fixed sash and one operable one that moves vertically.

Glider Picture Glider – (Or Double Vent) A three sash window with a vertical sliding sash on either side of a fixed sash.