When big residential towers are built - when are their "sale" dates recorded?

I'm trying to do some historical analysis of sale prices and it's dawned on me the numbers could really be affected when big towers consisting of hundreds of apartments all hit the market at once. I'm curious - when are the sale dates recorded? Is it when they are sold off the plan? Or when the contracts are settled?

 

They may be recorded as "agent advised" on unconditional exchange. But his data is overwritten after settlement when the import from the Land Titles office (or equivalent) is provided.

(Assuming you mean the industry databases like Core Logic's RP Data and Domain's Pricefinder etc.)

Bear in mind some developers had a habit of "buying" a couple of units within their own development, using other company names they owned. Why would they do that, I hear you say, and cost themselves stamp duty? To establish comparable sales in the building for Valuers to use on legitimate sales to the general public.

 

This.

 

Does this apply to Desktop valuation used by the Banks?

I've seen some good results in some recent sales, but Desktop valuations aren't really reflecting these results just yet.

 

Most banks use a system with a Core Logic RP Data engine. They also have some rules around not using exchanged but not yet settled sales or limiting the number of these to only 1 or 2 out of a total of 6 comps., depending on their whims.