I have started a building front for a customer (an apartment building). I have in the past used two methods to create window spaces. Most of the time I cut a solid wall (styrene) and use a nibbler to cut out the window spaces. However sometimes when I have a small wall and a lot of windows that need to line up precisely I use the 'cookie cutter' method as shown below. The wall is made up of individual pieces of styrene. Window spacing is set using hardboard spacers.
The brick sheet is laminated to the styrene with a spray contact cement. All windows and the door will need to be custom built.
I cut the door arch by first tracing a line with some tubing that was the right diameter, then I used a Forstner bit and a hammer to cut a groove deep enough to allow me to finish the cut with an exacto blade. A round sanding disc finished and smoothed the arch.
The brick sheet was extended down the entire length. I will cover it with 'concrete' sheets later on.
Joe