Six reasons to add a cased opening between rooms

While everyone is tearing down walls to create an open-space floor plan, there are several good reasons to create a little bit of separation by adding a cased opening between two rooms. The addition of a transom window is the charming cherry on top. 

Reasons to add a cased opening

Create a stopping point for paint

This was my primary reason to add a cased opening. As one open space, there was not a good stopping point between the designated rooms for paint colors. Our fireplace is at one end of this large space in the family room. We painted the wall around the fireplace Farrow and Ball’s Green Smoke, a deep smoky green color that I love. I didn’t continue this color on the remaining two walls in this room, because those walls both extend to the kitchen with no architectural stopping points. On one side, the wall terminates into the kitchen cabinets, which are a much lighter shade of green. You can read about the painted kitchen cabinets here. The two shades of green are in the same family, but it would have been too much of a good thing, and I like the lighter, brighter vibe in the kitchen. The cased opening provided a natural separation of spaces and a stopping point for the dark green walls in the family room.

Easier furniture placement

Create separation between spaces

Much like the awkward recliner, our kitchen table and chairs looked like they were just plopped in the space between the kitchen and family room. The cased opening created the appearance of a defined breakfast nook.

Easier art placement on walls

One of the side walls in the family room houses a large window that adds interest to the wall. The other, however, doesn’t have anything to break up the long run of blank wall. I always struggled with art placement on that wall. Installing the cased opening shortened the length of the wall by two feet and made art placement on that wall much easier and attractive.

The rooms actually look bigger

I don’t know why, but each room appears to be bigger. The space is pretty narrow and, without anything to break up the length, it had a bowling alley vibe—not the cozy look I was trying to achieve. Separating the spaces with the cased opening eliminates this bad visual. Somehow, each space seems wider. Maybe because the eye is not drawn to the length.

An opportunity to add or relocate outlets and light switches

We realized that the framed up walls would offer a good opportunity to run some additional wiring for outlets and light switches before covering them with drywall. I had always wanted an outlet in the breakfast nook space so that I could plug in my laptop when working at the kitchen table. The existing outlets were farther into the family room and required an extension cord. Further, the sconces flanking our fireplace were not hard wired. I used the battery-operated light bulbs when we wanted to turn them on. Those light bulbs are great for some areas, but they really don’t provide a lot light.

My husband, Dave, and my son, Drew, both have experience wiring houses, so they were able to add outlets on both sides of the new walls. They also ran the wiring to the sconces and added a handy light switch on the family room side of the wall. If you don’t have this kind of experience, it would still be a great opportunity to hire an electrician to run the electrical while the walls are open.

Determine the placement of your cased opening

Before you jump into building a cased opening, there are points to consider and calculations to be made.

Determine the location of the walls that will flank the opening

There are several things that come into play in determining the placement of a cased opening between rooms. The wall that houses the large window in our family room space also contains a sliding glass door that leads to our deck. We had to consider these two elements when determining the placement of the cased opening. But, it wasn’t as easy as locating it equidistance between the window and door. The location of studs in the walls and floor joists from the second floor, above, also came into play. Although this would be a non-load bearing wall, the wood frame that would create the walls of the cased opening had to be anchored into something. Dave located the floor joists and the studs on each of the side walls. We had a couple of options for placement based on these existing structures. The pencil marks indicating these locations on the ceiling and walls stayed there for months while I tried to make a decision on the placement of the cased opening.

Determine the size of the opening

While the goal was to create a separation of spaces, we still wanted a nice flow between the two rooms. We decided on an eight-foot opening, which left about 22 inches for wall space on each side. Ceiling height is a factor in determining the height of the opening. We have eight-foot ceilings and decided to match the opening height to the existing cased openings in our house—about 81 inches from the hardwood floors. This height allowed us to use pre-cut jambs purchased at Lowe’s on the sides of the opening. 

Calculate measurements for transom

While we were planning the cased opening, I had a brilliant idea—add a transom! I was a bit concerned that adding the cased opening would block the light coming in through the windows and door. A transom would allow for additional natural light to flow through the spaces. As we are home improvement enthusiasts, we took on the cased opening ourselves, but building the transom seemed time consuming and a bit out of our skill set. I found an online company, Transoms Direct, that makes custom transoms and delivers them in a timely manner. Our son watched a pretty lengthy video on the transom site that explained how to measure for the transom build. He had to determine the rough opening height of the cased opening as well as the transom height in order to do this. Some things to consider:

• Will there be crown molding above the transom?
• How close to the ceiling do you want the transom to land?
• Do you want to lower the opening to allow for larger transom windows?
• How wide is the jamb?
• How wide is the trim?

Build the cased opening

The steps we took to build our cased opening and install the transom follow, but this is more of a general overview. You will need some more advanced diy experience or construction know-how to build the walls and jamb.

Build the walls to frame the opening

The first step was to frame up the walls that would flank the cased opening. Dave and Drew, who was home for a visit, accomplished this pretty quickly. In order to anchor the frames to the walls and ceiling, existing drywall had to be removed. The scary part of this for me was watching as they drove screws through the frame and into the hardwood floors that we installed last year (no turning back at this point!). If we were just installing a cased opening, a framework would have been created to anchor drywall above the jamb, but since we were adding a transom, this step was not necessary.

Drywall the framed walls

With the transom on order, we continued to complete the opening. Drywall was up next. If you’ve never drywalled, let me tell you, it seems like the longest procedure in a construction project! The drywall goes up fast, but then it requires about 587 coats of drywall compound, with some sanding in between, to get a nice level, smooth finish. Okay, so not quite that many, but that’s what it feels like. 

Install the jamb

The jamb was built using pre-cut boards on each side and an 8-foot header across the top. Since this will create the finished portion of the opening, a nail gun was used to attach the jamb to the wood frame. Shims are inserted to level the jamb.

Install the transom

Next, a frame had to be created to house the transom. Careful measuring in advance is crucial so that your transom will fit perfectly into the jamb that you build. With the jamb in place for the opening, the transom was placed. Ours fit perfectly. We added cove molding around the transom where it met the frame for a finished look. A nail gun was used to attach the molding to the frame and the transom to the jamb with finish nails.

Attach the wood casing

A beautiful result!

I’m so happy that we decided to take on this project. It looks as if the cased opening always should have been there. We still have a nice open feel, but with a bit of separation that adds to the cozy vibe. Natural light flows through the transom windows keeping the space light and bright. The architectural detail definitely added some character and charm to our home.