Plunge pools are built for this
A plunge pool - compact, often around 3 by 2.5 metres up to 5 by 3 metres - is designed for exactly the small backyard problem. It still gives you a place to cool off, sit and relax, without needing a big footprint. It is also the lower-cost way into a pool.
Use the awkward space
A narrow side yard, a courtyard, the strip along a fence - small pools fit places a family pool never could. Placing the pool in otherwise wasted space can also leave the main yard usable.
Design it to feel bigger
A dark interior, a clean rectangular shape, frameless glass fencing and continuous paving all make a small pool feel like a considered design feature rather than a squeeze. Built-in seating along one edge adds function without adding footprint.
Heating goes further
Because a small pool holds less water, heating is cheaper to add and cheaper to run. A heated plunge pool is usable for far more of the year, which makes a small pool earn its place.