In my opinion it is quite an ugly building.
Subjective I suppose, personally I think it's quite a fine building, despite its history.
the extensions yes an eyesore , quite sure the cottages are ok, the house in its early years of completion may well have looked fine .
Again I think the beauty may well be in the eye of the beholder, yes the building is listed, the parts which you refer to as extensions is actually the original 18th Century farmhouse, the formal front is the extension.
The building was actually only listed in February 1987, the National Heritage listing reads as follows:
TOLLESHUNT D'ARCY PAGES LANE TL 91 SW(west side) 3/78White House Farmhouse GVII
TOLLESHUNT D'ARCY PAGES LANE TL 91 SW (west side) 3/78 White House Farmhouse GV II House. Late C18 and early C19. Red and gault brick in Flemish bond, roofed with slate. C18 range of red brick aligned N-S with 2 axial stacks. Early C19 crosswing of gault brick at S end, forming entrance front, with internal stacks at each side. C19 single-storey extension at N end. 2 storeys. Ground floor, 2 early C19 sashes of 16 lights, first floor, 2 similar sashes and one of 12 lights, all with flat brick arches. Central C20 half-glazed door in simple flat-roofed porch with 2 columns and 3 stone steps. Low-pitched hipped roof. Reported to have date 1820 inscribed on beam in roof. White House is shown on Chapman and Andre's map of 1777, then on another site approx. 400 metres to the west. Both were built by a charity established in 1626 by Henry Smith, salter and alderman of London, to which the farm still belongs at the time of survey, May 1985 (P. Morant, The History and Antiquities of Essex, 1768, I, 399).