We utilise principles of mass-energy distribution and similitude by ZPF equilibria to derive the values of the present Hubble constant "H0" and CMBR temperature "T0". It is demonstrated that a mathematical relationship exists between the Hubble constant and CMBR temperature such that "T0" is derived from "H0". The values derived are "67.0843(km/s/Mpc)" and "2.7248(K)" respectively. We also derive improved estimates for the solar distance from the Galactic centre "Ro" and total Galactic mass "MG" as being "8.1072(kpc)" and "6.3142 x10^11(solar-masses)" respectively. The construct herein implies that the observed "accelerated expansion" of the Universe is attributable to the determination of the ZPF energy density threshold "U_ZPF" being "< -2.52 x10^-13(Pa)". Moreover, it is graphically illustrated that the gradient of the Hubble constant in the time domain is presently positive.