Escalator at South Kensington Station

This guide says that there is no exit to the street from that station without using stairs:

http://content.tfl.gov.uk/avoiding-stairs-tube-guide.pdf

Maybe another one nearby will do for your arrival? Most tube stations do have escalators and/or lifts.

If you are arriving in London by air at Heathrow, an alternative to taking the Tube would be Heathrow Express to Paddington and taxi to your hotel from there ---it shouldn't cost too much as it is just across Hyde Park and then a bit more south. Tickets for the Heathrow express are now £6.99 each if you buy them 90+ days in advance on their website.

If you're coming into South Ken on the eastbound Piccadilly line (i.e. From Heathrow,) you'll have a 17 step staircase down from the platform to a walkway, then two escalators and a final 16 step staircase up to the street.

The westbound Piccadilly is accessible from the ticket hall without stairs, but you'll still have the 16 step staircase from the ticket hall to the street.

South Kensington has stairs only between the ticket hall and street, and between the District Line platforms and the ticket hall. Escalators from the Piccadilly Line to the ticket hall.

If I were you and coming from Heathrow, I would change from the Piccadilly to the District at Hammersmith (walk across the platform, no change of level) and get out at Earls Court, which has step-free access from the District Line to the street. Then get bus or taxi to the hotel.

There is now step free access directly from the Piccadilly Line to the street at Earl's Court (Olympic legacy!) so no need to change to the District.

You may want to consider a private car service. Blacklane.com is a very reputable car service, all over the world. You can go to their site, put in your information. They will immediately respond with a GUARANTEED price. They pick you up with a big enough car for all your luggage. A taxi costs more money, as you have the meter running and might run into traffic. We like having the security of the driver meeting us, right after we pick up our luggage. Then the driver helps us with our luggage. I am envious your are going back to our favorite city. We have been there five times and stayed up to two weeks each time. I absolutely live to go back. Happy Thanksgiving.

If you are concerned about stairs and heavy luggage, remember that Aster House has a lot of stairs. Granted that you may be staying on the First floor, which has no stairs from the entrance. But there are stairs from the street up to the door to Aster House that you will need to navigate.

I am staying in Aster House currently, and am going to fly home tomorrow. I would definitely consider taking a taxi from Heathrow to Aster House, especially if you are coming in from a long flight. I took the tube, but I am relatively fit and the stairs at South Kensington weren't an issue for me. John helped me with my luggage to my room when I checked in to Aster House, which was wonderful. I am on the Second floor and it is very comfortable.

Thanks Marco, I knew the lifts arrived at ground level but I didn't know if there were stairs between the Piccadilly Line platforms and the lifts.