Plenty of small ceremonies happen at a house rather than a venue. Somebody's backyard in Henderson, a patio in Summerlin, a grandmother's living room with fourteen chairs borrowed from the dining set. Couples choose it for the obvious reasons and we are glad they do. What surprises them is which part of the house ends up setting the schedule. It is not the yard, and it is not the kitchen. It is the number of doors you can close behind a person who is getting dressed. A ceremony for twelve guests and a ceremony for twenty are nearly the same event outdoors. Indoors they are completely different, because everyone has to get ready somewhere and then stay out of the photographs.
So the walkthrough turns into an inventory. One bathroom with a working door and decent light. One bedroom where a suit can hang without being moved twice. A flat surface near an outlet for the hair and makeup people, who need more room than anyone expects. A place for the officiant to stand that is not the kitchen, because the kitchen is where the caterer is. The house sets the timeline.
The homes that run easiest have a second small building on the lot. A pool house with its own half bath. A casita behind the garage. A detached converted room with a door to the yard. Two staging spaces instead of one removes the negotiation entirely, and it gives the couple somewhere to sit alone for ten minutes between the ceremony and the toasts. It also keeps guests out of the main house, which matters more than it sounds like it should when the main house belongs to a parent who is also a guest at the event.
What that structure is called, and whether one can be added, is a question for the firms that build them. Kingdom & Co, a design-build company in Las Vegas, describes a casita as a small standalone structure on the property, often used as a guest house, home office or pool house, and lists casitas and additions alongside its custom homes and remodels. Its page also notes that Las Vegas, Henderson and Clark County each set their own size limits, setbacks and zoning rules, and that HOA and CC&R restrictions can apply on top of those. That last part is the answer to the question most couples are really asking, which is whether the idea survives the neighborhood.
None of this is a reason to build something for a wedding. A wedding is one afternoon and a casita is not. The reason it comes up is that it changes the question worth asking at a site visit: not how many guests, but how many rooms with doors, and whether any of them have a bathroom attached. The answer says more about the run of show than the head count does. It also says whether a vow renewal at a grown child's house is going to be comfortable for the couple, who are usually the two people with the least private space at their own event.
So when sending photos of the yard to whoever is planning the day, send the rest of it. The hallway, the bathroom door, the outlet next to the mirror, the side gate the caterer will use. Fourteen people in a home that fits fourteen is a better afternoon than twenty in a home that does not, and small weddings work in the first place because nothing about them is being stretched to fit.