It was the perfect spot. Our California ranch style house had a large picture window in the front room. The window extended from a few inches above the floor to only a few inches below the cathedral ceiling. The walls and ceiling were redwood stained knotty pine and the floor was a matching hardwood. The window looked out over a flower bed, shrubs and the expanse of front lawn. It was the perfect window to be replaced with a bay window.

The window was nearly square. It was 72 X 72 inches. We considered a bow window, but elected to install a bay window instead. We just felt that our particular house looked better with three panel bay window rather than the multiple panel bow windows. Our intent was to fill the seat board of the bay with potted plants we had sitting in front of the current picture window. The new arrangement would give us a little more space in the room and improve the overall appearance of the house. It was time to go shopping.

Scratch vs. Pre-built Bay Windows

When we first got the idea of installing the new window, I began gathering plans for building bay windows. Thumbing through books and magazines, and the Internet search engines, I found several plans for building bay, casement and garden windows from scratch. I also found that undertaking such a project was going to be unnecessary. Most of the major window manufacturers, such as Pella, Milgard and Anderson make both completely pre-assembled bay windows as well as pre-built components for replacement windows.

These days very few contractors will take on the project of building a bay or bow window from scratch. It simply isnt practical when for the same or less money they can install a high quality pre-built window. If the contractors use pre-built windows or components for new house construction or renovation projects, then we could do the same for our remodeling project, we reasoned.

Installing a bay window can easily be a do-it-yourselfer project. Before you go the diy route, however, you may want to line up a contractor to help out if necessary. This is not going to be a job that you can complete during a Saturday afternoon. Chances are you are not going to finish it in a weekend, for that matter.

You are also going to want to line up some help. Bay windows and window components are heavy. At least they are too heavy for one person to manage.

Be sure and check out the weather forecast, including the long range forecast. Installing the window means opening a hole into your home. It can take a couple of days to get the new window in place and sealed. The last thing you want is for rain to come pouring in on your floor, walls or furniture.

Be sure and check your city or community construction codes. There may be special local requirements, such as having safety glass in low profile windows. You are probably going to need a building permit anyway, so that is also a good time to check the codes.

Tools and Materials Needed

The tools you will need for this project include a tape measure, a framing square that you can also use as a straight edge, a circular saw or miter saw, crow bars, drill and bits, level, stapler, utility knife, tin snips and a caulking gun.

The materials you will need include the bay window unit, the support brackets, nails, roofing paper, shingles, roofing nails, exterior grade silicone caulking and fiberglass insulation. You will also need 1X6 inch boards for the window skirting. If you are enlarging an existing window, or if you are installing the window in a space that was previously the wall, you will also need 2X4s for cripple studs and additional framing.

Basic Installation Steps

1. Establish window position in the wall. Remove the existing window. Measuring the bay window, mark on the exterior of the house the opening needed for the new window. Using your circular saw, cut the required opening.

2. Framing. Build the framing for the new window. This will likely include cutting through existing studs and putting in a new header, rough sill, jack studs and cripple studs.

3. Install the support braces. A window up to five feet wide will take a minimum of two support braces. A wider window will need three.

4. Set the window in place. Lift the bay window on the support braces and slide it into the rough opening. Shim as necessary to level the window. Anchor in place.

5. Build the window roof. Set the roof frame on top of the bay window unit and nail in place. Fill the space between the roof and the top of the bay window with insulation. Fasten the roof sheeting to the frame and cover with roofing paper. Install the drip edges and the flashing and then shingle.

6. Install the window skirting around the bottom of the window. Fill will insulation and then attach the skirt bottom to seal the underneath side of the window.

7. Seal the edges with silicone caulking.

This is a list of the basic installation steps and they have been abbreviated in the interests of simplicity and space. The window unit you buy will have complete installation steps. Take it from the voice of experience; it really makes the project go much more smoothly and it will be completed in much less time when you read and follow them.

In our case, I had two friends helping with the project. We have worked together on other projects and work together well. We had the old window out and the rough framing completed on Saturday afternoon. We buttoned up the hole with plywood overnight and went back to work the next day. By Sunday evening we had the new window installed and the roof and skirting completed. On Monday afternoon I finished sealing up the outside and completed the trim work for the inside.

And, we were right. It was the perfect spot for a bay window. It looked great from the outside. Inside, it became the focal point of the room and added a special charm to the house. The window gave the house added character and value.

When it came time to sell the house, it was one of the features that were particularly attractive to the buyers.