10kW/35 kW heat pump, cost-effective for a heating area with heat pump suitable?

Hello

I am looking to replace my standard central heating with a heat pump to reduce costs. My house is about 200m2, and I don't know how much power I would need to heat it in winter. As far as I know, there are heat pumps from 10 kW to 35 kW.

Thank you in advance for any response.

I assume you will need the same kW number later as you do now - unless you also change something about the insulation. The heat pump makes sense especially if you have low flow temperatures.