P1 cars have 4 hoses that make up the heater hose assembly. You should also change the top and bottom radiator hoses and the 2 oil cooler hoses.
It's also common for the bleeder hose coming from rear of cylinder head to overflow bottle to fail. Change the one to the radiator bleed as well. There's also the hose from the bottom of coolant reservoir to the metal hardline, and a small rubber line for coolant to turbo.
Worth doing the thermostat +housing at the same time as it is plastic.
If you get genuine hoses you know you'll get another decade of life out of them. You don't get a 2nd chance if any hose splits, you'll cook the engine.
