Insulating suspended timber floor ‐ do i need to do the lot?

[Coliander]

So, I'm looking at insulating my floors.
1980's Bungalow, suspended timber floor.
Cost is a bit of an issue at the moment, and I'm wondering if there's any reason not to do the primary living areas first (Bedroom and Living room), then revisiting next year to install insulation under the floor in the hallway and office once I have a little more money put aside.
Kitchen and bathroom are already done.

I'm no expert on thermodynamics, but as the underfloor cavity is essentially shared across the entire house, would I be seeing any benefit at all if I leave the hallway and office uninsulated?
I'm aware that insulating the lot would be the ideal solution, but if that isn't feasible, is it worth doing half the house for the time being?

Ta.

 

[blup]

Doing half will help reduce the heating bill. The insulation retains the heat in the room, so although some will escape to adjoining uninsulated areas, less heat will escape if the underfloor is insulated.

Blup

 

[Coliander]

Wonderful. Ta!