The evidence
Each criterion with what we found, where we found it and when. Anything we could not confirm says so.
NTH criteria
NTH Framework v1.2. Score 14.8 (raw 11.2 of 100), calibrated so the best hotel in this edition (Santa Monica Proper Hotel) reads 90. Evidence retrieved 2026-10-22.
Sleep0.0 / 24
The room as an instrument for deep, uninterrupted, circadian-aligned rest.
Mattress & sleep system
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 5 pts
Unknown
Bedding & textiles
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 4 pts
Unknown
Sleep programme & pillow menu
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 3 pts
Unknown
Blackout
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Circadian & warm evening lighting
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
In-room red light
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Acoustic quiet
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 4 pts
Unknown
EMF & Wi-Fi-off options
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Air0.0 / 12
What you breathe for eight hours a night: filtered, fresh, smoke-free and unperfumed.
In-room purification
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 5 pts
Unknown
Ventilation & building standard
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 3 pts
Unknown
Smoke-free policy
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Fragrance-free & low-allergen rooms
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Water0.0 / 12
Clean water to drink, and to shower and bathe in.
Filtered drinking water
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 5 pts
Unknown
Shower & bath filtration
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 5 pts
Unknown
Gentler pool & hydrotherapy water
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Nourishment0.0 / 10
Food and drink that heal rather than merely please.
Organic & local sourcing
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 4 pts
Unknown
Clean-ingredient standard
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 3 pts
Unknown
Clean minibar & in-room hydration
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Nutrition guidance
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 1 pts
Unknown
Movement5.0 / 10
The means to train, stretch and move, indoors and out.
Gym completeness
Hotel-reported · across the property
Gym on the wellness floor.
Classes & studios
Hotel-reported · across the property
Movement studio; classes included in membership tiers.
Swimming
Hotel-reported · across the property
20 m pool.
Outdoor activity
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Holistic Wellness6.2 / 19
Healing traditions and the recovery technology that complements them.
Spa facility
Hotel-reported · across the property
Guerlain Spa: nine treatment rooms, vitality pool, sauna, steam.
Traditional & integrative modalities
Hotel-reported · across the property
Reflexology with Andrea Hurst (earlier NTH research).
Mind & breath
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Heat therapy
Hotel-reported · across the property
Sauna and steam.
Cold therapy
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Photobiomodulation & PEMF
Hotel-reported · across the property
Photo-biomodulation light therapy in express facials.
Clinical longevity (IV, HBOT, diagnostics)
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 4 pts
Unknown
Materials & Setting0.0 / 13
What touches the skin and surrounds the stay: finishes, products, cleaning, and the landscape beyond the door.
Natural, low-VOC finishes
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 3 pts
Unknown
Clean bath & body amenities
Not yet reviewed · in the best room
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Non-toxic spa & nail products
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Non-toxic housekeeping & plastic-free operations
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Green & blue space
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Walkability & low-impact mobility
Not yet reviewed · across the property
Unknown. We have asked the hotel.
0.0 / 2 pts
Unknown
Our review
At a glance
- Fragrance
- 1 not met, 4 not yet reviewed
- Air
- 5 not yet reviewed
- Cleaning & care
- 4 not yet reviewed
- Sleep & materials
- 1 not met, 4 not yet reviewed
- Water & pools
- 4 not yet reviewed
- Food
- 2 not yet reviewed
- Light & quiet
- 2 not yet reviewed
- Building
- 3 not yet reviewed
Two not met; the rest not yet reviewed.
2 not met23 of 25 not yet reviewed
Counts cover the 25 scored criteria; the other 5 windows are context.
Checked
Read the full profileThe ledger
Fragrance
Added scent is the most common complaint from sensitive guests, and the hardest thing to see on a booking page.
No added fragrance in rooms
Not yet reviewed.
No scent marketing
Not yet reviewed.
So far, the hotel says: L’Atelier Guerlain is a salon for fragrance, make-up and hair, with ‘gold-bottled perfumes along a backlit wall’.
Our note. Whether the hotel scents its lobby, corridors or ventilation is not stated.
How we know
What we look for. No signature scent diffused through the lobby, corridors or ventilation system.
Why it matters. In a US population survey, about a third of adults reported health problems from fragranced products. A scent pumped through shared air reaches every guest, and there is no way to opt out of it once you are inside the building.
Source: Steinemann, Air Quality, Atmosphere & Health, Fragranced consumer products: exposures and effects from emissions ()
Source 1: Hotel website: wellnessUndated · read 22 Oct 2026
Fragrance-free laundry
Not yet reviewed.
Unscented bath products
Not metacross the property
The hotel says: The London perfumer Azzi Glasser developed a fragrance for the hotel, ‘embodied in a special collection of bathroom products’.
Our note. Whether unscented toiletries can be supplied on request is not stated. Ask before you arrive.
How we know
What we look for. Fragrance-free toiletries in the room by default, or on request.
Why it matters. Fragrance ingredients are among the most frequent causes of allergic contact reactions to cosmetics. An unscented option lets sensitive guests use what is provided instead of packing their own.
Source: EU Scientific Committee on Consumer Safety, Opinion on fragrance allergens in cosmetic products ()
Source 2: Raffles website: rooms and suitesUndated · read 22 Oct 2026
Unscented spa options
Not yet reviewed.
Know something about fragrance here that we don’t? Tell us
Air
What you breathe for eight hours a night: smoke history, fresh air, filtration and anything burning in the room.
Smoke-free property
Not yet reviewed.
Opening windows
Not yet reviewed.
So far, the hotel says: ‘Light pours through tall sash windows onto views of Whitehall and Horse Guards.’
Our note. Whether the windows open is not stated.
How we know
What we look for. Guest rooms have windows or doors that open to outside air.
Why it matters. The US EPA lists opening windows, when outdoor air allows, as a way to dilute pollutants released indoors. An opening window lets guests air a room themselves when it smells of cleaning products or new furnishings.
Source: US EPA, Improving indoor air quality ()
Source 3: Hotel website: stayUndated · read 22 Oct 2026
Filtered fresh air
Not yet reviewed.
In-room air purifier
Not yet reviewed.
No in-room combustion
Not yet reviewed.
Know something about air here that we don’t? Tell us
Cleaning & care
How a room is cleaned, treated and prepared, and whether a request for a gentler clean is actually honored.
Low-chemical housekeeping
Not yet reviewed.
No ozone or biocide treatments
Not yet reviewed.
Low-chemical pest control
Not yet reviewed.
Sensitive-guest preparation
Not yet reviewed.
Know something about cleaning & care here that we don’t? Tell us
Sleep & materials
The textiles, mattress and floor you spend the night closest to, and how allergen-aware the room is.
Tested or organic bed linen
Not yet reviewed.
Mattress materials disclosed
Not yet reviewed.
Hard floors
Not metacross the property
The hotel says: The rooms and suites ‘feature customised carpets, fabrics and wallcoverings’.
Our note. Whether any room has hard floors is not stated. Ask if you have a dust-mite allergy.
How we know
What we look for. Hard, cleanable floors in guest rooms rather than wall-to-wall carpet.
Why it matters. Dust mites live in carpet, and US health guidance for allergic sleepers is to replace wall-to-wall carpet in bedrooms with bare floors, which can be cleaned completely between guests.
Source: US National Institute of Environmental Health Sciences, Dust mites and cockroaches (undated)
Source 2: Raffles website: rooms and suitesUndated · read 22 Oct 2026
Allergy-friendly rooms
Not yet reviewed.
Pet-free rooms
Not yet reviewed.
So far, the hotel says: A staycation package invites guests to ‘bring your dog for a pet-friendly retreat’.
Our note. No pet-free rooms or separate cleaning routine are described.
How we know
What we look for. Rooms or floors where animals are never allowed, cleaned to a separate routine.
Why it matters. Pet allergen can stay on carpets and furniture for months and travels on clothing. For allergic guests a room animals never enter matters more than any amenity.
Source: US National Institute of Environmental Health Sciences, Pet allergens (undated)
Source 2: Raffles website: rooms and suitesUndated · read 22 Oct 2026
Know something about sleep & materials here that we don’t? Tell us
Water & pools
Drinking water, shower water and pool air.
Filtered or tested drinking water
Not yet reviewed.
Water safety plan
Not yet reviewed.
Shower filters
Not yet reviewed.
Shown for information; not scored.
Outdoor or low-chloramine pools
Not yet reviewed.
So far, the hotel says: The spa has a twenty-metre pool, a vitality pool, a sauna and steam.
Our note. Pool water treatment and ventilation are not described.
Shown for information; not scored.
How we know
What we look for. Pools are outdoors, or indoor pools have dedicated ventilation and monitored combined chlorine.
Why it matters. Chloramines irritate the skin, eyes and airways, and they build up in the air of indoor pools without enough ventilation. Outdoor pools, and good ventilation for indoor ones, keep levels low.
Source: US CDC, Chloramines and pool operation ()
Source 1: Hotel website: wellnessUndated · read 22 Oct 2026
Context, not scored: almost every pool in this catalog is outdoors, so it says little about one hotel against another.
Know something about water & pools here that we don’t? Tell us
Food
Allergen care first; where the produce comes from second.
Allergen-aware kitchen
Not yet reviewed.
Garden or organic produce
Not yet reviewed.
Shown for information; not scored.
Know something about food here that we don’t? Tell us
Light & quiet
Darkness and silence at night, and radio-quiet options for guests who want them.
Darkness and quiet
Not yet reviewed.
Radio-quiet options
Not yet reviewed.
Shown for information; not scored.
Know something about light & quiet here that we don’t? Tell us
Building
The materials a hotel was built and renovated with, how it handles damp, and what third parties have certified.
Low-emitting materials
Not yet reviewed.
Leak and mold response
Not yet reviewed.
Building certification
Not yet reviewed.
Shown for information; not scored.
Know something about building here that we don’t? Tell us
Notes & sources
- Hotel website: wellness, Undated · read 22 Oct 2026
- Raffles website: rooms and suites, Undated · read 22 Oct 2026
- Hotel website: stay, Undated · read 22 Oct 2026
- Hotel website: the building, Undated · read 22 Oct 2026
- Hotel website: fitness, Undated · read 22 Oct 2026
Room count: Per the hotel’s website, which describes 120 rooms and suites. Hotel website (opens the hotel’s website)
Photographs: Raffles London at The OWO; Raffles London at The OWO; Raffles London at The OWO; Raffles London at The OWO; Raffles London at The OWO; Raffles London at The OWO; Raffles London at The OWO
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