After Safety, planning is the most important step in building your haunted house. Ask yourself these questions:
Safety is always your top concern. Keep this in mind at every step of your haunted house project, from conception to the point that your guests are making their way through the haunt. Check out our Haunt Building Safety page for tips.
Are there local ordinances, licenses or inspections (fire or other) required in order to run your haunt? For a home haunt, the answers may be a bit loose, but for a professional haunt, it will most likely be yes. The best way to answer this is to check with your local city or town government, as the answers may differ depending on your location.
Insurance: Is insurance required for haunted houses? If so, where do I find haunt insurance? Check our Insurance For Haunted Houses page for more information.
This determines what type of materials you will need. If you have access to use a pre-existing building that looks like it's directly out of a horror movie (such as an old prison, abandoned hospital, creepy old house, gothic mansion, etc.), you're already off to a great start. However, if you're building from the ground up, you will have complete control over the look, so there are advantages to both methods.
Measure the dimensions of the area in which you wish to build your haunt. If there are multiple rooms, spaces, hallways, etc., write down the dimensions of each separate area. This will be very important when it comes time to build.
Will it be a single, all-encompassing theme, such as a haunted asylum, hospital, prison, castle, mansion, etc.? Or will you have different themes in each room, much like traditional haunted houses? Many traditional haunts dedicate individual rooms to specific horror films or characters like Jason Voorhees, Freddy Krueger, The Ring, Silent Hill, Babadook, etc., as well as more general themed situations or characters, such as a hospital room with a crazy doctor, a bedroom occupied by a tormented, deformed, ax-weilding psycho, or a good ol' scary clown in his own circus oriented room.
Who do you expect to be the guests in your haunted house? Little kids? Teenagers? Your family or friends? Or, perhaps you're going to be running a professional haunt - In which case, you still have to decide whether you're running a haunt for all ages, or adults only / 18+.
This seems like an obvious question, but this determines whether your haunt is meant for commercial (money making) purposes, or if it's just a fun project for you and/or your friends. A third option is to make a not-for-profit haunt that does collect money from visitors for specific charitable purposes. In this case, you may also want to decide whether to give guests a set price for entrance, or to allow them to "donate", perhaps with a suggested amount. And you should also decide which charity or charities that you will donate your profits to. In order to do this, you must be sure to register your haunted house as a non-profit entity, so you don't get into legal trouble.
These will be your blue prints. Before figuring this out, you definitely need to know the answers to the questions above. Once you have these answers, you can start your design ideas. You're going to want to actually draw these on paper, or in a graphic design application of your choice. After sketching your basic design (rooms, hallways, entrance, exit, etc.), you can get more specific with what items and/or people will be in each of the areas of your haunted house.
SketchUp is a 3D modeling program that can be used for haunt design. It's free for non-commercial use, and they even have a repository of free pre-designed items and layouts that you can search and download, from haunted houses to walls, individual rooms, chairs, etc.
Your design should not be just a series of rooms, hallways, etc. It should create the path that your guests will take through your spooky narrative. For example, if you are mimicking a haunted, abandoned hospital, perhaps your entrance should mimic a dilapitated hospital entrance with zombie EMTs dragging a corpse in the front doors, leading your visitors into a lobby area with a ghostly receptionist to greet them at the front desk, who might then direct them down the hall to an emergency operating room with an insane doctor who threatens to throw your guests on his operating table, etc. If you're designing a more traditional haunt, the segments don't necessarily have to connect a story in the same sense. Your first room could be a gruesome murder scene, second could be mimic a popular horror film, etc.
After answering the previous questions, you should be ready to get the answers to this one. The materials you require depend on whether you're building inside of an existing structure or creating a new one, the amount of space alloted, your theme, design, etc. You can start in a broad sense, such as "I need something with which to build the structure (walls, roof, floor), along with certain props for this room and that other room, this type of lighting", etc. You can get more specific with this after you've completed a basic outline.
It's important to plan far enough ahead of time that you will not only have your haunted house built in time for your opening date/time, but that you will have extra time for test runs, extra time to make any needed changes, adjustments for safety, etc.
If you plan on having actors and/or volunteers in your haunt, ie: the people who scare your guests, you will need to find them somewhere. Check out our page on finding actors for haunted houses.
If you want people to come to your haunt, you have to let them know that it exists. Check out our page on Promotion & Advertising for haunted houses.