Autograph Collection, Tribute Portfolio, Luxury Collection for Marriott and similar brands at other chains are soft brands because they consist of independent hotels that have their own name. Standards are generally lower; like the requirement for a gym or a pool. Some like Tribute Portfolio may not be required to have an all-day restaurant or room service.

So, it may make sense for a hotel within a historic building with limitations due to the historic nature of the building and any historic preservation restrictions to affiliate with one of these brands instead of Renaissance and similar brands that at least on paper have uniform requirements that all properties must have.

Additionally, Marriott and other chains generally require a hotel owner to renovate rooms every 7-10 years. The St. Pancras opened in 2011. So while some premium rooms were purportedly renovated, most of the rooms have not been renovated since the hotel opened. I imagine there's an extensive floor-to-ceiling update required. Furniture, carpets, wall treatments, probably new or extra electrical outlets, maybe TVs, perhaps improvements to the bathroom, etc. You get the idea.

Marriott is probably willing to forgo some of those requirements by converting or, using hotel parlance, re-flagging the St. Pancras from Renaissance to St. Pancras.

There could be other things at play. The club lounge could have been a money-loser as a club lounge. So it may make more sense (or cents) to redevelop it into a restaurant, bar, or other commercial space.

It could also be that the owner, Harry Handelsman of the Manhattan Loft Corporation, is unhappy with the Renaissance brand and thinks an unbranded hotel at the upscale to luxury price point would do better than a Renaissance, which admittedly is one of Marriott's more tired brands. Renaissance, in my opinion, is a fairly directionless brand with no real consistency. There are some genuine 5-star Renaissance properties but then a lot of dumpy properties in North America that date back to the 1980s or 1990s when Renaissance was part of Stouffer and Ramada. Marriott has tried making Renaissance a kind of corporate boutique brand but has never put as much money or resources into the brand as W. Also, unlike W, Marriott franchises Renaissance. Marriott does not franchise W. So, W is generally more consistent and a little bit more luxury than Renaissance.

And then don't forget that London is an extremely competitive hotel market. The Park Hyatt just opened. Hyatt went from having one Hyatt Regency to having four Hyatt Regencies. Until recently, Marriott's only 5-star luxury properties were arguably the Edition and W. The JW Marriott Grosvenor House has declined in recent years and will struggle once the Rosewood opens in the former United States Embassy a couple blocks away at Grosvenor Square. Marriott unable to a Ritz-Carlton due to the original Ritz owning the trademark is also about to open a St. Regis in a former Luxury Collection property. Then you have all the 5-star-plus hotels in London that make Edition and W look like a Courtyard or Holiday Inn.