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New planting - required to comply with BS5837 ?

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BS5837 (referring to NHBC 4.2) makes very clear recommendations as to the distance that new planting should be from existing buildings. The distances are greatest for tall, 'thirsty' deciduous trees in clay soils adjacent to buildings with shallow footings.

Can anyone offer a view or legal precedent as to how much duty there is to take BS5837 into account, on the part of a developer designing, or the Planning Authority in determining a planning application?

The case concerns an extensive mitigation planting carried out as part of a planning permission.

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Perhaps the foundations have been designed to accommodate the trees' influence, or perhaps there are no shrinkable clays. If the answer to both those is neither, or if you don't know the answers, then speculation is pointless. But if they are 'yes' then ...

 

5837 in regard to these issues is secondary to well-established industry standards, particularly NHBC and building regulations. Annex A is 'informative', a lower level of imperative than the rest of the Standard. It talks of the 'need to' avoid damage. At best one can say that in saying 'need' it is echoing legal liabilities and the cost/life implications for buildings if the advice is not followed.

 

I know of no precedent citing 5837. There are several subsidence cases citing NHBC and two citing 3998.

 

So could done get hammered for not consulting 5837 or not taking its advice? Probably not in isolation. Could a Council be liable for imposing conditions that ignore Annex D? Hmmm, maybe but not in isolation. Such conditions would be unreasonable and should be overturned. I think someone in the design team would be responsible for spotting the conflict between conditions and likely subsidence. Ideally before conditions were formally imposed.

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BS5837 (referring to NHBC 4.2) makes very clear recommendations as to the distance that new planting should be from existing buildings. The distances are greatest for tall, 'thirsty' deciduous trees in clay soils adjacent to buildings with shallow footings.

Can anyone offer a view or legal precedent as to how much duty there is to take BS5837 into account, on the part of a developer designing, or the Planning Authority in determining a planning application?

The case concerns an extensive mitigation planting carried out as part of a planning permission.

 

The scenario you paint is a little vague. Your words imply that the planting has already taken place....and there have been some implications? Is negligence alleged? For a precedent to have been set the case would have had to be heard in the Court of Appeal and I am not aware of any such cases. Furthermore I am not aware of any cases where lower courts have considered such matters and delivered a judgment that might be of use to you.

 

In terms of a view: planting potentially large trees en masse near large numbers of domestic houses on clay soils where the foundations have been designed without knowledge of large trees coming along is a recipe for disaster. The case studies of Peterborough and Milton Keynes are interesting as that is precisely what they did and are now paying the price. I wouldn't be surprised to hear that their insurance bill (from claims) is larger than their "tree" budget but I have few hard facts.

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Thank you for your replies. i have tried to be concise and stick to principles rather than air too much detail in public.

However, to add a little 'flesh to the bones'. I am the owner of property adjacent to the mitigation planting. (I am also a builder and have a working knowledge of planning and the Building Regs.).

The trees have been planted. The soil is a Class One low plasticity clay and the foundation depth of at least some of the adjacent properties is around 400mm.

NHBC4.2 gives a distance of 27m for oak, the planted distance of the nearest trees is as little as 8m.

Outline PP has been granted and the planting is in response to a condition of the OPP. The area of planting is greater than that required for mitigation. I am trying to keep both developer and Planning Authority 'on side' in the hope of negotiating a compromise but am also trying to establish any legal recourse.

This might have to be through seeking enforcement.

Neither applicant nor the planning Authority appear to have even considered applying the yardstick of BS5837 or NHBC4.2, to which it defers.

These standards are much more commonly used for construction near existing trees.

I have had sympathetic words but no concrete undertaking to resolve the situation. There are further nuances but those would be for a PM.

 

I can see that there would be legal liability were a link to be demonstrated between the planting and future damage. The degree of duty to only plant or give permission to plant in accordance with BS5837 / NHBC 4.2 is less clear.

As a builder, I am obliged to comply with NHBC4.2 and the equivalent Building Regs.

Any further thoughts would be welcomed. I shall try to locate the Peterborogh and MK cases.

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Some further clarification:

The trees were planted a year ago, so no damage yet!

I am trying to get a minor modification to the planning so that some of the trees closest to my property can be removed. My property is much more affected than others.

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Sorry but I do not wish to post a picture.

It is a mass planting on 2.5m centres, both ways.

There are 6 or 7 species.

The nearest rows, which include oaks, are 6m from a recently built (pre-trees) wall on 900mm deep footings and 8m from a 1930s wall on 400mm footings.

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Sorry but I do not wish to post a picture.

It is a mass planting on 2.5m centres, both ways.

There are 6 or 7 species.

The nearest rows, which include oaks, are 6m from a recently built (pre-trees) wall on 900mm deep footings and 8m from a 1930s wall on 400mm footings.

 

Trees are not the problem. Are there shrinkable clays and/or insufficiently deep foundations? That's all you need to think about.

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Just to be clear the buildings and indeed the soil were there before the trees.

People seem to think BS 5837 is only about new construction near trees but it is equally about planting near existing buildings.

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Trees are not the problem. Are there shrinkable clays and/or insufficiently deep foundations? That's all you need to think about.

 

I totally agree Joules. Any future management, ie standard tree care, will accommodate the usual perceived tree related issues. Without shrinkable clay in this instance, there is nothing else to be done IMO. The trees are a condition of planning. Retrospective changes are hard to implement without real evidence.

 

To the OP, I suggest finding out specifically what soils you may have, this link would provide you with some coarse level indication of the types of soil you may have in your area (it is not absolutely definitive however!).

 

Further to that, you can send away some soil to be analysed - usually 1kg is needed, and this will determine if you actually have shrinkable soil or not. There are several soil analysis services (ask Google...) that will be able to complete this analysis for you.

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