The catch at The Standard, London

The hotel's own room page opens with the Standard King Interior and says of it, in its own words, that there are no windows. It is an interior core room of 19 to 26 square metres, dressed with plants in the shower, and the hotel pitches it for a red-eye or a late night rather than for a morning. The catch inside the catch is that the first room with daylight, the Standard Queen, is 16 to 19 square metres, so you lose floor area to gain a window, and the Standard Single is 13 square metres with a twin bed.

The room in the photographs is a Premium King or a Premium King View, 33 to 37 square metres with bay windows and a bath. Every category from the Standard Queen up promises triple glazing and abundant daylight; only the interior king promises neither, and among the rooms only the Premium King View names St Pancras; above them, the ninth-floor Studio Suite does too.

The FAQ answers the spa question with a gym. It is open 24 hours, for guests only, with treadmills, Peloton bikes, yoga balls and free weights, and that is the whole of it. There is no pool, no treatment room and no sauna, and the suite perks list, which runs to a raincoat, sneaker cleaning and a Peloton wheeled to your door on request, shows where the hotel's idea of pampering sits. At a design hotel two minutes from Eurostar that is a choice, not an oversight, but it is a choice you are paying for. Guests rate the location highest and value lowest, and the gap between the two is the missing spa.

Decimo and Sweeties share the tenth floor. Decimo's own site runs dinner to 1am on Thursday and 2am on Friday and Saturday, Sweeties is a cocktail bar and discotheque, over-18s only, open Wednesday to Saturday until 11pm, midnight and 1am, and the Library Lounge downstairs keeps going to 2am from Thursday to Saturday. The hotel sells triple glazing for a quiet night, and guests tend to report quiet rooms against Euston Road; what they raise is the music in the public rooms and the late tenth floor. Guests rate their sleep as highly as the stay as a whole, so this is a mood catch rather than a decibel one.

The other half is what is shut. Decimo closes on Sunday and Monday and serves lunch only Wednesday to Saturday. Sweeties is dark Sunday to Tuesday. The Rooftop on the eleventh floor is seasonal, opening from about April and closed through the winter. A winter Sunday here is Isla from 5pm, Double Standard, and the lounge.

Breakfast is not included on the standard rate; the FAQ points you to a Get Toasty package or to Isla from 7am. On Isla's own menu the continental breakfast is 23 pounds, the Full Breakfast Package, which adds one a la carte dish and unlimited speciality coffee, is 33, and a discretionary 15 per cent service charge is added to the bill. On the room itself the hotel adds an optional 5 per cent service charge on the rate, distributed to the housekeeping and maintenance teams, and it pre-authorises 100 pounds a night on your card for incidentals. Late checkout is 20 pounds an hour after noon. None of it is hidden, all of it is on the hotel's own FAQ, and guests report the extras on the bill. Add it up for two people over two nights: four Full Breakfast Packages are 132 pounds before the discretionary 15 per cent, and two hours of late checkout on the last morning is another 40, before the 5 per cent on the room.

This is a hotel for people who are out at night, and its rules say so. Decimo's own site admits over-16s only after 8pm and enforces a dress code with no flip-flops, shorts or ties. Sweeties and The Rooftop are over-18s throughout, and Sweeties carries the same dress code. The family room, the Standard Double with Two Double Beds at 36 square metres, sleeps up to four, and the hotel takes dogs free of charge, so it is not that families are unwelcome; it is that after dark the top of the building is closed to them, and the ground floor, Isla and Double Standard, is where they eat.