Bs rating, I'm confused now...

[Thehardwaremonkey]

I don't know if I'm being treated as an idiot or not -help!

 

I have a single eucalyptus cider gum tree in my garden, it's stem is 510 in radius at 1.5m height, approx 12m tall and in a healthy state. Which makes an RP radius of about 6 metres(?).

The tree is on my land and close to a neighbouring development, so has been given a bs5837 rating of C3 by them/their report for the following reasons, is this correct, does lack of biodiversity make it a C3 tree always as a Eucalyptus?

 

Their response to me when I queried the category...;

With regards to the categorisation of the tree, this decision was made

following an appraisal of the tree, the species and its location.

Eucalyptus offer no foraging value to our native invertebrates and are of

little value to local biodiversity therefore the tree does not have the

'material or other cultural value' that would require it to be categorised

as a 'B'. Eucalyptus as a species are also particularly vulnerable to wind

throw which will direct future management in the future and limit its

wider amenity value.

[daltontrees]

Not at all. Classifying a neighbours tree as C is going to have no effect on a development! It will still require the same protection as an A category tree.

 

Classifying trees as A,B, C or U is obviously limited, but if you are classifying all your run of the mill trees as A's or B's there is no differentiation. The aim of an AIA IMO is to help a designer decide which trees are worth keeping and how much space they require. If you don't differentiate the ones worth retaining with the "unremarkable" then how can the designer make an informed choice?

 

Sorry, I don't really get this. I was speculating that the surveyor was trying from the outset to make the case for develoing within the zone of influnece of the tree and thus wants to state that it is hardly worthy of protection.

 

It's for the designer (and the Council) to decide which are retained, not the surveyor. In theory and occasionally in practice the design is not known to the surveyor. Without teh context of a design it is impossible to say at the time of survey what should be retained, or even what the threshold for retention should be.

 

It is entirely possible for every tree on a site to be category A. The designer can still make an informed choice, he presumably then can decide which of the trees to keep. Or all of them. Or none of them. And the Council can then decide to TPO them all, or let them all go or put conditions in to protect certain ones.

[daltontrees]

What is rare or unusual. Helliwell in Amenity Valuation of Trees and Woodlands suggests less than 5 such trees in the County. On that basis I doubt it would be rare or unusual, even in Scotland.

 

Size is important on a number of counts. A small tree, any nursery tree, with the potential to grow to maturity is no the same as such a tree at maturity. The biggest difference you will see when looking is the size. Also, size matters when considering landscape qualities. Visual importance may not be just about size, but it is a large part. Small trees being less prominent.

 

The tree has to not only meet the Category definition, but also one of the sub-category definitions. BS 5837 para 4.5.3 For a tree to qualify under any given category, it should fall within the scope of that category’s definition (U, A, B, C) and, for trees in categories A to C, it should qualify under one or more of the three subcategories (1, 2, 3).It may in part fit B, but it doesn't fit any of the sub-categories. If its not A it can't be B1, B2 relates to groups/woodlands, and there's no known conservation or cultural value, so not B3.

 

All that's left is C. C2 relates to groups and woodlands. However it does fit C1 & C3

 

Ed

 

Well that's quite the point. Words without definitions are prone to many interpretations.

 

I am adamant that size is largely irrelevant to the categorisation. It is important for landscape value, amenity value, arboricultural value etc. and presumably that is a big part of the choice of which tree the designer chooses to retain. But it's not the surveyor's choice. He/she reports category and size, among other things. The designer will take all these things into account, but would never just choose what to retain by category.

 

I didn't follow your logic at the end there ("It may in part fit B, but it doesn't fit any of the sub-categories. If its not A it can't be B1"). I think the tree is possibly B1 and C3. B1 is the highest, so it's B1.

[daltontrees]

That's what I'd been thinking, surely since it's not in the ownership of the prospective developer, it's not within their gift to "do" anything to the tree other than that which crosses the boundary.

 

It's a funny old game, such knowledgable folks, using a common system, arriving at such different conclusions (mindful of the limited info.)

 

We're all doomed!

 

Nah, they just haven't realied I'm right yet:biggrin:

 

But seriously, the Council could TPO the tree even if it is not in the development area, and since the TPO covers the tree wherever its parts extend, the development site would be affected. This to my mind is one of teh reasons 5837 requires the recording of off-site trees.

[kevinjohnsonmbe]

Nah, they just haven't realied I'm right yet:biggrin:

 

But seriously, the Council could TPO the tree even if it is not in the development area, and since the TPO covers the tree wherever its parts extend, the development site would be affected. This to my mind is one of teh reasons 5837 requires the recording of off-site trees.

 

Hi Jules,

 

The issue of TPOs on boundaries was discussed at the recent Barcham's / Mynors seminar. It was suggested that, even if TPO'd, the neighbour (in this case the prospective developer) would have a right to abate a nuisance (overhanging branches / roots) without seeking consent regardless of TPO.

 

Caused quite a stir amongst some of the audience! It's was alluded to briefly in the "Barcham seminar. Charles Mynors, Trees & the Law" thread starting at post 26 / 27.

 

Not sure if there is an England / Scotland law difference??

[kevinjohnsonmbe]

Nah, they just haven't realied I'm right yet:biggrin:

 

 

:thumbup1:

[benedmonds]

Sorry, I don't really get this. I was speculating that the surveyor was trying from the outset to make the case for develoing within the zone of influnece of the tree and thus wants to state that it is hardly worthy of protection.

 

I was disagreeing with your speculation. Classifying a tree as a C because it is unremarkable is a reasonable thing to do. The report presumably stated that as tree belongs to a neighbour it will still need protection..

 

It's for the designer (and the Council) to decide which are retained, not the surveyor.

 

The whole point is the designer is a non arb. The arb is providing the information for the designer to use. The surveyor does NOT decide which are to be retained, but by ranking the trees gives the designer information to make an informed decision. The council may disagree that is their prerogative..

 

It is entirely possible for every tree on a site to be category A. The designer can still make an informed choice, he presumably then can decide which of the trees to keep.

 

If all the trees are exceptional.... However if you are more realistic and set the bar lower, you are able to differentiate the great from the average and the nothing special. The designer will then have information that may allow them to design accordingly.

[daltontrees]

Hi Jules,

 

The issue of TPOs on boundaries was discussed at the recent Barcham's / Mynors seminar. It was suggested that, even if TPO'd, the neighbour (in this case the prospective developer) would have a right to abate a nuisance (overhanging branches / roots) without seeking consent regardless of TPO.

 

Caused quite a stir amongst some of the audience! It's was alluded to briefly in the "Barcham seminar. Charles Mynors, Trees & the Law" thread starting at post 26 / 27.

 

Not sure if there is an England / Scotland law difference??

 

I have always thought the necessary abatement exemption nuisance existed. I don't think iut's any different up here as the law has developed on a similar basis.

[daltontrees]

.... However if you are more realistic and set the bar lower, you are able to differentiate the great from the average and the nothing special. The designer will then have information that may allow them to design accordingly.

 

Sorry, again I disagree. The bar is set by BS5837. It is possible for a report to create additional distinctions between good and exceptional, but I think it is incorrect to do this by manipulating the definitions in 5837. One could for example add a category A+ or even A++, but it would still be A.

 

You're kind of promoting the argument that would allow say drivers to be marked numerically in their driving test, and the top 25% being allowed to pass, regardless of whether they are safe to drive.

 

If it is done accordign to 5837, the designer and the LA can assess it relative to other sites that have been done on the same basis. Otherwise no one has any objective information to make a decision on. That to me is realistic. Shifting the mean and deviation to create a normal distribution of some kind isn't.

[jaime bray]

Yes, I just don't think I explained this very well. For every tree a surveyor is not just faced with a choice of A, B, C or U, but with a preliminary choice of 1, 2 or 3. So a free-standing veteran that is ghastly looking and not providing much amenity could be considered a low grade 1, not a 2 at all, and a high grade 3. I have always gone on the basis that if I have 2 choices, say C1 (low arboricuktural value) and A3 (high conservation value) then I must choose A3.

 

In the case of the OP's tree, the surveyor has chosen 3 (conservation) and then given it a low subcategory (C3) because Eucalyptus is not native. A low subcategory might well be right for conservation value. However, if it is a perfectly good arboricultural tree in a garden, it should also have a A1 or B1 value.

 

So what I meant was A always trumps B always trumps C (stating the obvious). Given the choice, the tree should have been reported as A1 or B1, adn that even if it was in relally poor condition because of root damage it shoudl have been reported as C1 rather than C3.

 

Jules, the first part of your answer just shows how subjective it all is. A free standing veteran, ghastly in appearance, etc. Some people would look at said veteran tree with veteran features as less than ghastly, and the prominence, and history of it may add to the landscape from afar. So cat 2 would be totally adorable in their eyes. The gnarliness of it would lend some users of said landscape to reflect upon the usage of the land in years gone by and Thurs it's contribution to the broader landscape could be argued. The human mind works in so many ways that for us to stand and say no, that's definitely a a,b,c123 is not feasible. Or experiences throughout our careers up to and beyond consultancy will alter or opinion, so the document is furthermore interpreted by everybody in a different manner. The years for each category and the writing therein are interrupted differently by many. Regardless of what we think, it's subjective.

 

Apologies for long paragraph folks

[benedmonds]

If it is done accordign to 5837, the designer and the LA can assess it relative to other sites that have been done on the same basis.

 

I don't want to going to keep going on about this but I think you are SO wrong..

 

Simple scenario, a plot with two trees, in one corner is a 150 year old oak good condition in the other a 50 year old leylandii also in good condition. The designer has room for a house but only if one tree is removed.

 

A report in the way I was taught would grade the leylandii as "unremarkable" C it would be removed, protection for oak put in place, house built, no fuss no TPO's (the tree is not threatened) no expensive, time consuming fannying between council and designer etc.

 

A report grading them as both A's would help nobody. The designer would have no information to say which tree is worth retaining and which is not. The designer might put the house in the Oaks RPA, the TO would then TPO it, causing extra time an expense. Then might try to use engineering solutions to protect the tree etc, etc..