[Talk-GB] Accuracy of cadastral parcel alignment

[Tom Hughes]

On 03/03/2021 13:04, Tom Crocker wrote:

> I spotted the new land registry imagery in JOSM - thank to those who 
> have made this available - and the claim of perfect alignment in the 
> info box. I assume this means perfectly aligned with Land Registry's 
> data and therefore some default legal position on ownership (although my 
> memory from buying a house was that boundaries aren't just about what is 
> marked on a map). Anyway, looking at the layer it seemed closer than the 
> Bing alignment to what I have been mapping to based on quite a lot of 
> GPS tracks, but still offset by about 1 (metre?) in either direction. 
> Although there are going to be boundaries that have shifted and 
> presumably inaccuracies in the surveying, would it be fair to assume 
> that the majority of their data is likely more accurately placed than I 
> can estimate with multiple tracks from my phone GPS, particularly around 
> new estates where I guess OS have done a recent survey with far better 
> equipment than me?

To quote what HM Land Registry say on every title plan:

   "This title plan shows the general position of the boundaries: it
    does not show the exact line of the boundaries. Measurements scaled
    from this plan may not match measurements between the same points
    on the ground.

The UK does not operate a system of precisely surveyed land
registrations like a typical cadastral system.

Rather titles are basically just shown by lines scrawled on an OS map
in the rough area of the boundary...

Tom

-- 
Tom Hughes (tom at compton.nu)
http://compton.nu/