Great — here are highly recommended boutique hotels known specifically for their lively, well-designed public spaces (lobbies, bars, rooftops, restaurants, pools or communal lounges). I picked properties across the U.S., Europe and Asia so you have options by city; each entry notes what makes its public spaces vibrant.

• Yours Truly, Washington, D.C. — big, open-plan ground floor with a buzzy lobby café/bar, planted seating areas and coworking-style spaces that make the lobby an all-day social hub. (en.wikipedia.org)

• Thompson Seattle (Seattle, WA) — dramatic open lobby, rooftop bar and a public-facing courtyard; strong local design and a lively restaurant-bar program that draws locals as well as guests. (en.wikipedia.org)

• The Chelsea (New York City) — historic, artist-centered property whose public rooms (lobby, cafes and bars) have long been social and cultural meeting points. (Iconic for its communal, creative atmosphere.) (en.wikipedia.org)

• Mollie Aspen (Aspen, CO) — boutique property with a highly styled lobby bar and communal areas designed around social lounging and après-ski gatherings. (Noted for its design-forward, hospitality-oriented public spaces.) (vogue.com)

• Soho House Barcelona (Barcelona, Spain) — members’ house/hotel with a lively rooftop pool, restaurant and bar scene that creates a constant social buzz across public areas. Great for daytime lounging and nightlife. (thetimes.co.uk)

• Maison Souquet (Paris) — small luxury hotel whose richly theatrical reception, salon and bar are designed for lingering conversations and intimate social evenings. (Public rooms are a major part of the experience.) (en.wikipedia.org)

• Art'otel Hoxton (London) — art-filled public spaces (gallery, ground-floor café and rooftop) programmed with exhibitions and events so the hotel functions as a neighborhood cultural hub. (marieclaire.co.uk)

• The Mark (New York City) — celebrated for its lively Mark Bar and restaurant scene; public areas are stylishly designed and often attract a fashionable local crowd. (en.wikipedia.org)

• Yours Truly / similar Vignette/independent-boutique hotels (general trend in US) — many newer boutique properties emphasize large flexible lobbies, coffee-to-cocktail bars, and coworking/communal seating to create vibrant daily programming. (Trend noted across recent hotel coverage.) (en.wikipedia.org)

• (Wild-card) The Netty — a very small, theatrical boutique that turns unique spaces into social moments; notable for creative public areas that are conversation starters. Good if you want eccentric, highly designed communal spaces. (livingetc.com)

Quick tips for choosing the right “vibrant public spaces” boutique hotel

• Look for hotels that advertise a lobby bar/café, rooftop, pool bar or member’s club — those spaces are most often programmed to be social.
• Read recent reviews or event calendars (hotel websites and local press) — a hotel can have a beautiful lobby but still be quiet unless it programs DJs, happy hours, exhibitions or pop-ups.
• If you want locals in the mix (more energy), target hotels with popular restaurants/bars open to the public or those affiliated with members’ clubs (Soho House-style).
• For daytime activity, check whether the hotel hosts coworking, coffee service or weekend brunches — those bring steady foot traffic.

If you want, I can:

• Narrow this to one city or region (examples: New York, Los Angeles, San Francisco, Miami, London, Paris, Barcelona, Tokyo), or
• Pull up current availability, rates and the hotels’ event/program calendars for specific dates you have in mind.