arsie wrote:My structural/soil engineering consultancy, the NHBC, the local authority building inspector are but three of the people I found that had data on all the different tree species and their effects....... it would be easy to base any legislation on this data
Lets assume all your experts are talking about the NHBC Chapter 4 Foundations, document. The information on tree to dwelling distances is based on the Kew Root Survey (Cutler & Richardson 1981). Interestingly the authors of the survey have said that the information provided by the survey should not be used in the way it is to determine foundation depths. Also, it only applies to highly shrinkable clays, which the vast majority of soils around the country aren't. So how would you legislate using this information and get it right, with great difficulty I would suggest.
arsie wrote: if you chop the trees down you might get 'heave'
You might not. It depends on many factors not just
arsie wrote:species of tree and the type of subsoil
arsie wrote:when plans are considered a great deal of attention these days is paid to the landscaping and the layout and species have to be specified. You won't see many willows, for example, one of if not the most thirsty of all trees.
That's as maybe, but are the trees, of whatever species, that are to be planted as part of the landscaping scheme taken into consideration when the engineers calculate foundation depth. And what about all that grass on those well tended lawns which invariably is overlooked.
arsie wrote: inconsiderate people who thoughtlessly plant trees without thinking or caring about the consequences
But people are entitled to plant what they like, (within the law), where they like in their garden. Do you really think that a government of any colour is going to give a home owner/occupier the legal authority to dictate to their neighbour what they can plant and where on the basis that something might be a problem at some unspecified time in the future in a small part of the country dependent upon the soil characteristics and the weather. An Englishman's home is his castle to each and every politician, and I can assure you they won't be changing their minds any time soon.
As for the high hedges legislation. As I said previously, it's easy to legislate, the difficult bit is getting it right.