With an extended family, you might think about a vacation rental apt. or house. DC is a small city, but no one place will be walking distance to all the sites. (Plus after walking around all day you really just want to get home and relax, in a neighborhood with lots of restaurants, cafes, shops etc. nearby.) The Red Line Metro is the least convenient for tourists, but not a huge deal - just add 10-15 min. extra per trip, longer on weekends as you have to change trains.
There are three primary listing sites for vacation rentals now; Homeaway.com. Airbnb.com and Homeescape.com. (VRBO.com is also still active, but basically a duplicate of Homeaway, both owned now by Expedia.)
Homeaway & AirBnb charge a 9%-12% booking fee. Homeescape.com does not charge any booking fees, but it is newer and has fewer listings.
1. Search results can vary a lot depending on what device you are using - desktop, laptop, tablet or phone.
2. Enter your exact dates if you have them, but if you are flexible you can search without dates.
Sorting by neighborhood will make it easier. On Homeaway, you have to scroll down to the bottom of the first page to see the neighborhood list.
You can also just type a neighborhood in the search box - "Washington DC Columbia Heights" for example.
The most convenient neighborhoods for tourists, with lots of rentals and nearby Metro stations are - Columbia Heights, Dupont Circle, U St., Eastern Market, Foggy Bottom, Penn Quarter and Capitol Hill. (Woodley Park and Cleveland Park are also good, but have few rentals.) For all listings, but especially Capitol hill - check the map first thing. Many people stretch the boundaries, but this is especially bad for Capitol Hill.
Some good bargains can also be found in more "developing" neighborhoods like LeDroit Park, Shaw, Bloomingdale.
For larger houses - 3-4 bedrooms, also look at the neighborhood of Petworth and Brookland.
3.On Homeaway you can click on the "sort by" box and choose "price low to high." You might not be looking for the cheapest, but it makes it easier to organize. This will also let you scroll past all the bad listings. Don't even bother looking at anything under $100.00 per night.
You can also do a "map search" - but you have to enlarge the map quite a bit to see all the rentals. This is useful however, to find properties close to a Metro Station. Metro Stations are blue squares with a white M.
Do not even look as "Best Match," "Most popular," or "HomeAway Sort" - these are meaningless.
4. If you find a place you like - WRITE DOWN the listing number on a piece of paper! You might be looking at several properties, get confused and because of search algorithms, you might not be able to find it again.
5. Rates vary a lot by season. "Average Rate" is basically meaningless. You need exact dates to get exact rates. Also check the cleaning fee & tax policy. Some owners include cleaning & tax in the rate, some don't. It can make a big difference.
6. Email the owner. Tell them a bit about yourselves, ask any questions. Airbnb & Homeaway favor properties with "Instant Book" or "Book it Now" but you don't have to click these. Many owners also have their own websites.
If you want, post the exact listing number, or better yet, a link here and we can tell you more about the location, etc.
Airbnb.com in DC has over 6000 listings, but if you know the city well and are looking for a specific neighborhood, it can be a good option. Airbnb offers rooms in shared apts. or an entire apt. They don't let you sort by price, but you can enter a price range. You can also sort by neighborhood.
They charge the guest 9% booking fee plus 14% DC hotel tax, so add 23% to whatever the listed rent price is. Do be aware that most condos and rental apts. do not allow Airbnb rentals, so be absolutely sure you are renting only from an owner of the entire property, or with written permission from their condo board.
Several posters on this Forum want me to "disclose" that I own a vacation rental myself. I'm happy to. If you can find it among the 3,000 or so available, you will be very lucky!