It's about the fact that there are usually not too many comparable sales for properties with 2 dwellings on one title for the valuer to compare against. That is why sometimes these valuations come in way lower than expected. With granny flats in western sydney this is changing as more and more are built.
Extract of notes from a recent valuation report below:
Although thinly traded, the market for dual occupancies in the suburbs of western Sydney has increased steadily over the last 12 months with the majority of interest coming from investors due to the high rental return generated from two separate residences. We advise the construction of detached flats in the rear yards of comparable properties in this location has increased significantly and therefore this market is considered to be slightly volatile as it has experienced different market conditions to those experienced in the greater Blacktown Council area in recent times.
The subject property is situated on a regular shaped inside allotment, providing a south-eastern aspect within the established area of Emerton, opposite Emerton Preschool. Local and regional shopping facilities as well as train services are available within the local neighbourhood of Mount Druitt.
The property comprises a single residential allotment of 564 sqm which is considered to be a average lot size for the subject locality.
The property comprise a dual occupancy development with an proposed extensions of an older 3 bedroom dwelling to the front and 1 bedroom flat to the rear. The main dwelling has a living area of 85 sqm, outdoor areas of 6 sqm, carport area of 17 sqm. The granny flat has a living area of 34 sqm.
VALUATION RATIONALE:
We have considered the highest and best use of the property to be that of a single residential holding and have utilised the direct comparison approach as our primary method. However, our searches revealed limited recent sales of directly comparable properties within the subject locality and therefore we have extended our searches to include sales of comparable dual occupancies and single residential dwelling with varying accommodation in the greater Blacktown Council area, and have made the appropriate adjustments in our analysis. We have then utilised the summation approach as our secondary method, with the added values depreciated accordingly to reflect the current market value. The sales considered in this report were the most relevant as at the time of inspection.