Rough Openings | Standard Framing Dimensions

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• This site is very helpful for those of us who don't do this every day. Thank you for making it available.

  • Brooks - Thanks for the compliment. I hope you come back often for more advice and information.

    • Thank you Todd!
      The simple way of explaining without long descriptions is appreciated. Anybody can understand easily. Very useful.
      Wimal Lokuliyana

• plz enter the standard size of door and window.

• If i am building an addition when i stand my wall up it is 1 inch higher than the old wall can i make the cornish even by making my new rafters with a longer overhang,

  • You'll have to make a deeper bird's mouth and really focus on the roof geometry.

• Your web site says window rough opening should be 2 1/2" over actual. The flange on window is not that large, so i respectfully suggest your info is wrong. !/2 " to 3/4 is what I use. Did I miss something, Thanks, Rick

  • Rick,

    Here's what the article says:

    "Window rough openings are framed in a similar way to door openings. Again I like to use examples so let's say we've got a 3' wide by 4' tall window unit then the rough opening would be 38-1/2" wide and 50-1/2" tall. Now, most window manufactures actually specify a standard rough opening which is typically a bit tighter so it's best to follow the manufacturers recommendations when possible."

    As I noted, some manufacturers use a tighter dimension. 2-1/2 inches is the industry standard, many window manufacturers adjust after framing. Framing usually happens, then windows are ordered based on rough-openings.

    • I think what he was meaning by 2 1/2" wider than the windows was 2 1/2" larger than the actual window pane itself. Just like a door, a 3'0" door is only 36", but once you add the jamb thickness and the space between the door and jamb, you actually have more like 37 3/4". Same goes with windows, if you want an actual window pane, let's just say 24" wide, then once you allow for the frame, and insulation, you would end up being 2 1/2" over. Just how I understood, I hope I didn't confuse the topic more than it was. ?

• will the rough opening for a double door still be the nominal dimensions + 2.5 inches in both height and width?

  • Yes sir :) However, if you have certain special doors that number might change, some outswing French doors and some Andersen units are different so check the spec with the door.

• We are building a small workshop with just a plain concrete floor. With no subfloor going in, and thus no finish flooring, what is the measurement to use on this type of door application for roughing in?

  • Troy - Typically we'll make that rough opening another 3" wide so we can attach a pressure treated buck in the opening so there's something to shim/attach the door framing. Good luck.

• Good Day Todd

  Your site has been very helpful, and I plan to visit it more in the future.

  Question: when framing a rough opening for a man door for a shop, do I still require the bottom plate or do I make my measurement minus the bottom plate.

  • The height is from the floor surface to the bottom of header. Depending on the number of plates you'll need to consider that.

• would like to install a standard size exterior door on a wall that is 84" to the bottom of the ceiling studs. The 2 2x4's in the ceiling. Is there enough space?

  • Cheryl,

    It really depends on if that's a bearing wall, and if so, how much structural support is required above the door. 84" is only 1-1/2" above the top of the rough opening for a 6'8" door. That basically doesn't leave any room for a structural header.

• Helped me refresh my memory. Thank you very much.

• We are building a greenhouse and bought old windows and doors. We are considering installing the windows and doors without jambs since they did not come with them and we can use the 2x4 framing to screw the hinges into. Does the 2-1/2" include the jamb? If I don't have a jamb? Should I just go with 1/2" wider and longer when framing?

  • Great question! 1/2" will likely work well with no jambs. You'll need to install jamb stops but that clearance will probably work pretty good. Certainly no smaller, and up to 3/4" would be better. Good luck.