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I don't know, but I should thing that a timber floor will be much
cheaper and easier to install than a suspended concrete one! Even
with insulation and nice boards....



No, it isn;tt. And its draughty as well because you have to let
underfloor spaces breathe or risk rot.

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Given that the OP already has a suspended floor it should be cheaper to
refurbish that rather than complete replacement by either infill or concrete
block and beam.

I recently replaced my suspended timber floors including the addition of
50mm insulation and the cost was about £150-00 per room - 4m x 4m approx..
The job was actually quite straightforward and caused very little
disturbance or mess.

Cic.