Duplexes are two homes, often conjoined by a single wall. Sometimes, their heating and cooling systems are also conjoined, although their electrical systems are frequently separate. Still, if you are looking for a new home, there are some reasons why a single family home is preferential to a duplex.
Privacy is huge for most people, and most duplexes deny you of some of your privacy. That is directly related to the fact that your home shares a wall with your neighbor's home. Anything and everything that you do that is loud, from playing music to verbal fights to sex, can be heard through that wall. Even if you own the duplex in which you reside, and you heavily insulate that one wall, it will not block all the noise. In a single family home, your neighbors will only hear you if your windows are open or your music is cranked all the way up.
Circulation and Ventilation
In a single family home, you only smell what goes on in your home because you only have a single ventilation system. In duplexes that share a ventilation system, smells can travel between homes because of the way that the forced air circulation system operates. That means that if your neighbor is a smoker, or you burn dinner, both sides of the duplex can smell it. That may be quite off-putting if you hate cigarette smoke, or your neighbor hates the smell of burnt food.
There are a lot of duplexes that share driveway spaces or open garages. Open garages are two garages occupying the same space. There is no wall dividing your garage and your neighbor's. Many people find this very unsettling because it means that they have to constantly lock up their car(s) and everything else they store in the garage just to make sure these items remain safe. You never know what kind of neighbors you have until things begin to go missing.
If someone ends up sharing just driveway space, it could be even more difficult. Generally, someone always gets blocked in in the driveway, and then the person who is blocked in has to wake up and gently motivate the others to move their vehicles in order for the first person to back out and get to work. When you have a single family home, you may still have to move cars, but at least they are cars to which you have access and for which you have keys. No other adult in the house has to move a vehicle.Share