We really need to know your budget to make recos.

Also - not sure who your party is made up of - will 2 triple rooms work? Or do you need another configuration?

Yes - Budget and bed configuration and then we can make useful suggestions. Also - when/how many days?

End of June/beginning of July

Would like to stay under $400 per night

5 people; possibly a 6th person

Me, my husband and our 3 kids (21, 18, 15) 6th person may come (son's GF)

Not sure how many nights, probably 4 or 5

Thanks for your help!

What configuration of beds/bedrooms do you need?

We stayed here with 6 (2 grands, 2 adults, 2 kids). Might be a touch cozy with 6 adults (and would require some bed sharing). Nothing fancy, but very functional and we liked the location. Well under your budget. Looks like they have availability starting early July but not late June.

http://www.vrbo.com/323395

I'm sure there are other options around that the more experienced can recommend. We loved having a flat/apartment.

Trip report:

http://www.fodors.com/community/europe/londongreenwichoxford-with-kids-and-grandparents.cfm

Thanks indy_dad...great trip report!

Configuration:

1 bed: husband & wife
1 bed: 2 brothers
1 bed: 2 sisters

What area/areas would be good to stay in for the most convenient access to the sites I mentioned?

Things are fairly spread out in London, so as long as you are located near a tube stop you should be fine. I would highly recommend you stay in an apt. I think it will be more fun for you all to be in the same space together. I would get a good map, I like the Streetwise maps, and see exactly where the apt is located and proximity to a tube stop.

There were six of us, and we stayed in an apt in Belgravia/Knightsbridge (I just looked and, unfortunately, it appears to only be for long-term rent now). But we did really like the neighborhood, well located and very nice. We booked this apt through Great Trips Unlimited, but I have used VRBO.com several times for other trips.

Our kids were younger when we did this trip, but they are now closer to your kid's age and I know they would love to go back to London - you will have a fabulous trip!

In case you are interested, here is a link to my trip report with pictures:
http://www.fromhometoroam.com/2012/05/london/

Must you stay in the same apartment? There are plenty of rental agencies that specialize in tourist rentals and many have more than one flat in the same building.

If you want a hotel you would need 2 rooms - either a double and a quad or two triples. $400 per night for these two rooms is not a very large budget.

You may e able to find an apartment that will sleep 6 - but you will have to look carefully at the bed configuration and you may only get one bath (IMHO not a great idea).

You may find a place that has two apts - perhaps a one-bedroom and a studio - for your budget. But I would start searching now.

We always stay in a very central area but I don;t think your budget will cover that. Look at South Kensington, which is near some Museums and not too far from other sights by tube - and seem to have a lot of rentals. But look carefully at how close the apts are to a tube station.

I have just recommended Waterloo Travelodge for Britcher. It may work for your family. Family rooms have a queen bed and extra single. We stayed for 4 nights. Great price, location, comfortable, clean, quiet. Three of us stayed for less than AUD$200 for 4 nights! Would stay there again definitely.

SusannahT: The OP hasn't been around for a couple of months - the thread was topped by an advertiser