It is expected that the future UKs grid inertia will reduce as the UK moves towards decarbonisation. The consequence is that National Grid may have to have to increase its spending on primary frequency responses, to keep the frequency within limits. There is however, potential for National Grid to reduce this cost with the assistance of a dynamic domestic Demand Side Management schemes. This paper considers how domestic appliances may be utilised to help with frequency response. This paper looks at the potential size of a domestic appliance service using a droop based scheme to participate in dynamic Demand Side Management for frequency response and determines the impact of this on frequency response costs.