Commercial RENT index from the VOA rating lists — FOUR points, one per
list (2010 / 2017 / 2023 / 2026), each dated at that list's antecedent
valuation date (2008-04-01, 2015-04-01, 2021-04-01, 2024-04-01), with the
2010 list = 100.
READ `basis` AND REPEAT IT when you quote a number: the index is derived
from VOA rateable values — the Valuation Office Agency's assessment of
open-market rent at each valuation date — NOT from advertised rents, and
it is not a capital-value index. It moves in four steps; do not
interpolate between them as if it were monthly, and date each point by
`avd_date`, not `list_year`.
Why it exists: it covers the sectors the repeat-sales capital index
cannot (INDUSTRIAL_WAREHOUSE trades in portfolios, not Price Paid), for
every VOA sector and 320 local authorities.
`sector`: omit for ALL, or a VOA sector (OFFICE, RETAIL,
INDUSTRIAL_WAREHOUSE, INDUSTRIAL_FACTORY, PUB_BAR, HOTEL, LEISURE,
HEALTHCARE, EDUCATION, ...). `area`: omit for national; a local
authority GSS code ("E08000003") or NAME ("Manchester", bridged to its
code). `start` / `end`: rating-list years, e.g. "2017".
`link_ratio` is the median rateable-value ratio between consecutive lists
over the hereditaments present in both (`n_constant` of them). An empty
`series` with `available_sectors` means the area is published but not
that sector; an unknown area is an error. UK only. Free.