We stayed at Sanctuary House Hotel on our honeymoon 20 years ago, when it was rather new, and not on the RS forum radar screen. I chose it on the basis of location and price, and liked it so much we returned several times, but now we enjoy longer stays in London and book apartments. I still recommend Sanctary House, especially for people who like to walk, as we do.
You are just 2 blocks from Westminster Abbey but on a quiet street away from the tourist crowds. From the hotel on Tothill St., it is a short walk north on Dartmouth Street past lovely historic buildings to the passageway down the Cockpit Steps to St. James Park, our favorite park for flower displays and water birds. You are 5 minutes from the Churchill War Rooms at this point. Turn left on the park paths and walk to the west end of the park and you are at Buckingham Palace. Or walk the loop to the NE corner of the park and walk The Mall to Trafalgar Square, gateway to the Theatre District and Covent Garden. For the Tower of London and St. Paul’s, you can catch the No. 15 double-decker bus east straight to the Tower, passing St. Paul’s and many historic buildings on the way. Ride upstairs for the best view. From the Tower you can take a boat from Tower Pier back to Westminster Pier to reach your hotel.
The hotel itself is a boutique hotel, with comfortable rooms above the pub where breakfast is served. Very different ambiance from a big chain hotel like Premier Inn. I compared prices for the 2, and found them similar, but it varies by date—-literally day to day for Premier Inn. Sanctuary House rates are lower on weekends, and they offer a discount of 25% for stays of 3 nights or longer. Both came in around £850-900 for 4 nights over a weekend, with August being less expensive than July, for rooms with comparable amenities (meaning a Premier Plus room rather than standard). But the Premier Inn prices are quoted without breakfast, while the Sanctuary Inn price includes breakfast (I did not check if that is continental breakfast or “Full English”. If you add breakfast at the Premier Inn, it adds £20-25 per night for 2 people.