Grantulla House has high local significance as one of the remaining guest houses that were so popular in the Dandenongs during the 1920s and 1930s. More recently, from the late 1960s, the former guest house has been used as a children's holiday camp and for short term accommodation. The building has been significantly altered internally and externally.

Grantulla House is set on a large property in an isolated setting, overlooking the Sherbrooke Forest Park from the north. The grounds contain evidence of the former nature of the complex, including a disused pool, water feature and terraced garden with picturesque views and planting. The building is in a very poor condition. It has been subject to a number of additions and extensions, predominantly to the rear and side faces. The front facade shows evidence of change, although it is relatively intact.

The older section of the house, dating from the turn of the century, includes a substantially proportioned, rectangular plan, timber single storey building with a dominant transverse gable roof. The main roof terminates to the east in a gable end roof, which forms a projecting bay to the south or front facade. This bay is mirrored towards the west corner by a gable end roof which projects from the main, transverse gable. These corrugated iron roofs and projecting bays are connected to one another by a flat roofed, south-facing verandah.

The projecting bay gable ends are timber lined and have overhanging bargeboards. Decorative, angled timber struts are fixed to the overhanging bargeboards, sitting proud of the wall structure. The verandah has a timber floor and posts and exposed rafters, with timber framed double doors to one side, adjoined by rectangular, timber framed strip windows. The eastern projecting bay has a pair of centrally located timber framed, double hung windows, which are fixed to the outside face of the wall. The west bay has been altered to include a bay window with large, multi-paned timber windows and a concave metal-lined roof.

Skillion roofed weatherboard additions are located to the south facade beyond the western projecting bay and to the west and north facades. Timber, gable roofed outbuildings are located west of the house.

Physical Conditions: Poor

Integrity: Major Alterations