In message , at 16:44:53 on Tue, 24
Feb 2015, Michael R N Dolbear remarked:
Oops, found
https://www.gov.uk/about-the-price-p...-from-the-hous
e-price-index-and-price-paid-data

Our House Price Index and Price Paid Data exclude:

all commercial transactions. By this we mean any transaction that
involves a transfer to a corporate body, company or business

transfers, conveyances, assignments or leases at a premium with nominal
rent which a
[...]
under a compulsory purchase order
[...]

So not exactly "excludes other than open market" but as above.

You snipped:

"sales that were not for full market value."

What I hadn't remembered was it also excludes:

"buy to let (where they can be identified by a mortgage deed)"

which is typically what could have been happening in several houses in
that particular street.

--
Roland Perry