If you've watched all the old vampire movies from the 1930s to about the 1970s, you've probably noticed that vampires are shown getting in and out of their coffins at sunrise and sunset.  the coffin was essential in the past because they are light-tight.  However, modern vampires don't need to sleep in them.  The energy-efficient features and blackout curtains of today's modern homes and hom designs means that vampires don't need to sleep in coffins in the basement or in the cemetary.  All they need is a lgiht-tight area to sleep during the day.

Why Do Vampires Need to Avoid the Light

The traditional vampire is highly allergic to light, specifically sunlight.  Depending on the vampire lore you subscribe to, the light either has a purifying effect on the vampire's putrid tissues, causing them to self-distruct and burn, or the UV part of the sunlight has a sterilizing affect that causes the same problem.  The vampire catches on fire and burns to death.  For this reason, vampires must stay out of sunlight, or they will be burnt to ash within a few minutes.

Vampires and Luxury

Vampires love luxury as much as humans.  This means thy'd much rather sleep in a bed inside a lavish home than in a filth filled coffin.  Living in luxury also means the vampire has a beter chance of attracting their food source - humans.  After all, who would you rather visit - a mysterious man living in a century old mansion or a dirty man living in a trailer park?  I think the answer is self-explanatory.  Most humans would rather cisit a mysterious man who lives in a mansion and serves expensive alcohol than one who lives in squalor and drinks coors light.