The absolute most important stage of the whole process of making a large diorama is the stage of planning. You absolutely have to spend more than a few hours drawing up sketches and making sure everything is exactly how you envision it. Once you start building the diorama it is very difficult to make major changes. You have to know ahead of time where all the major components will be located. This is standard practice for making any kind of complex object. Car makers and home builders create complete plans before they start building anything. You should do the same. This process doesnt just lay everything out for you though. It also serves as a great way to generate ideas. Your finished product will benefit greatly from planning. And I will explain how this planning stage can also save you money.
Size, Access and Usability
Another important thing to think about is portability and ease of use. I have built dioramas that were so large it was difficult for me to work in the center of them. I just couldnt reach that far in from the edge! If your diorama is this large you may want to consider building it in two halves and then when each half is completed stitching them together with materials. I highly recommend you build a custom table for a large diorama and you put it on wheels so it can easily be moved. You also need to ask yourself if the diorama is going to stay in the room you build it in. Will you be moving it to another location after it is done? If so, will it fit easily through doorways? You might not want to tip it sideways as you move it so it might be a good idea to make it in pieces or to keep one dimension to less than twenty-nine inches so you can get it through even the narrowest doorways.
A big diorama can be made with a low expense if you are very crafty and creative with materials. And twenty dollars will buy you enough paper towels and Plaster of Paris to make even the largest of dioramas. But if you want to use traditional hobby textures and trees the cost can quickly escalate. Trees alone will cost between fifty cents and a dollar each depending on the size. So if you have large forested areas with scores of trees the expense can quickly climb. You can have a big impact on the cost of your diorama during the planning stage.
The two biggest expenses for diorama making are water effects and miniatures. Miniatures can cost ten dollars each or more and realistic water costs around one dollar per ounce. And the ounces go very fast so if you want to keep the cost down be very frugal with bodies of water and dont make them deep! Again this can be carefully controlled in the planning stage.
Building for the ease of building
One of the biggest challenges I have when it comes to a large diorama is the addition of special effects like motors, working drawbridges, lights and sound effects. I consider these additions to be the things that take an ordinary project and turn it into something special. But this adds extra cost, takes time, and adds some difficulties to the process. And the biggest thing to think about in terms of these extras is the wiring. If you have planned your diorama well you already know where all the special effects go and you can pre wire all the wires before you create the plaster shell. This makes it so much easier.
But dioramas change and you never know exactly what changes you are going to want to make until you are well underway so I recommend you run extra pairs of wires to difficult areas and build the shell so there are access hole in the back, sides, and even bottom. These access holes will allow you to add more wires and objects without destroying the terrain.
Building a small project is something that can be done in an afternoon or a weekend but building a large project can absorb well over a hundred hours of concentrated work. And this can go up significantly if you want to achieve a high level of realism and detail. If you work on it two hours a day it still will take you several months to complete it. Its just good to consider the commitment to the project and whether you have the time to complete it.
Building a large diorama is one of the most exciting projects you can do. People go absolutely crazy over them and you will get a lot of compliments on your work. And even if you are not a skilled diorama maker you can make one that is just spectacular if you just plan ahead and follow some of these simple guidelines.