A ground source heat pump needs more space than an air source heat pump.
A typical horizontal system (trenches) needs around 700 sq metres minimum.
A vertical system (boreholes) needs enough space for the drilling rig to access the site, the boreholes themselves are only about 25cm wide and 100m deep. For a typical UK home one borehole is enough. If multiple boreholes are needed for larger properties / district heating systems, these are placed around 5-6m apart.
The pump itself is about the size of a standard fridge and will need to be set up in a utility room or something similar with a footprint space of about 1m x 2.5m.
For more details please speak to a local installer.