From Wikipedia:
“Radiant House is an architecturally notable building in Mortimer Street, in the City of Westminster, London. It is a grade II listed building.
The building was commissioned by Ernest Eugene Pither to honour the memory of Sophia Elizabeth Pither, née Bézier, and it was completed in January 1915. The building was designed by Francis Léon Pither, although a plaque on the building shows “F. M. Elgood, FRIBA” as the architect.”
From the Historic England entry:
“Commercial premises. Dated 1915. White faience with turquoise glazed brick. Free classical manner. 5 storeys, 3 main bays. Canted bay windows to ground floor separated by Ionic ‘Jacobean’ pilaster strips. Dentil cornice above ground floor. Continuous arcaded round-headed windows to first floor, with semi-Gothic Corinthian columns between. Outer bays to second and third floors with round headed architraved windows. Central 2 storey bay window rising through second and third floors, mullions and transoms, 2 and-3-lights, continuous Doric loggia at fourth floor level. Modillion cornice and decorative frieze above third floor; subsidiary cornice to loggia. Iron balustrade to loggia.”