A duplex is a house separated into two living units. Each almost always has its own door. Duplex home-building kits are available from a variety of manufacturers and are usually called prefab or modular. Concrete, steel building and post and beam kits are also widely available. The use of structural insulated panels has become common in kit building. SIPs are a solid wall piece bonded to expanded foam insulation.
Building a duplex home from a kit is quick and cheap. A moderately skilled do-it-yourselfer, with the help of a few friends, can build the home in a matter of days. Duplex houses built with SIPs are stronger and frequently more energy efficient. Building from a kit removes the costs of an architect or engineer. Building a duplex home from a kit carries the added advantage of creating income-producing extra living space. Using SIPs allows more flexibility in your design.
There's limited demand for duplex home-building kits, so you may have to engage in creative thinking. Many kit companies will allow you to design exactly what you want. They then work out the specs and quote you a price. From there the process is the same. Websites like Duplex House Plans Gallery are a good place for ideas. These sites offer their house plans for sale for you to give to your architect or builder, but you can look at the basic plans online. A less elegant solution is to simply buy two kits and put them side by side.
Before ordering a duplex home-building kit, take into account what parts you will have to supply in addition to the kit. Some kits don't come with windows, doors and roofs. Kits may not include wiring and plumbing, You'll need to build your own slab or basement for the duplex. Check local building codes and have the appropriate inspections done as your building progresses.
Prepare your site for your duplex home. Build the foundation. When modular parts are delivered, they're lifted into place and fastened. If your home kit comes with a roof, it is then put in place and finished. Next, install windows and doors, and complete the exterior finishes. Finish the interior, including plumbing, wiring and utilities. Install heating and air conditioning, then porches and decks. The final step for your duplex is to landscape your property.