Home suits a small, low-key group, a hired venue anything larger.
Hosting at home is relaxed and free to book, and it suits smaller, low-key gatherings. On private property you also skip the public-space licensing that organised outdoor events attract. The trade-offs are real, though: limited capacity, your own furniture and clean-up, no dedicated parking, weather cover to sort, and noise that carries to neighbours late at night.
A "free" park is rarely as simple as it sounds. According to
The Royal Parks, using a Royal Park for a commercial activity or organised event means applying for a licence or permit and paying a fee. Safety scales up outdoors too.
HSE advises that the same crowd-management principles apply even to free events on open ground, so you stay responsible for managing the space safely.
A hired venue gives you room to grow and takes the logistics off your plate: a defined capacity, proper facilities like loos and a kitchen, and a host who runs the space, in exchange for a hire fee and fixed hours. For anything beyond a handful of guests, dedicated
small party venues in London often deliver a more polished evening without the morning-after tidy-up.
Pro tip: Booking a private venue on Peerspace means you skip the public-space permit process you'd wrestle with in a park or on the street, since you're hiring a space that's already set up for events.