Looking for advice about building near trees

PennyD79

[FONT=&quot]Has anyone had any experience of building very near to trees? And [FONT=&quot]in particular, do you know about the [/FONT]costs of needing deeper, pile or raft foundations?[/FONT]

• [FONT=&quot]Did it significantly add to the overall costs?[/FONT]
• [FONT=&quot]Did you find builders were willing to take this on?[/FONT]
• [FONT=&quot]Did you face any other problems, long-term issues, hidden costs? [/FONT]
• [FONT=&quot]If the build work damages the roots, could the trees to become dangerous? Would we be liable?[/FONT]
• [FONT=&quot]Anything else we need to think about?[/FONT]

[FONT=&quot]
Thanks!

Background on our project:

We've been planning to do a two-story extension on the side of our 3-bed house in SE London for some time. This would replace a single story garage, and we'd be able to go a couple of meters wider, stopping just short of our neighbours' fence. There are no access issues.

Our neighbours 4 leylandii/conifer-type trees are just the other side of the fence, and are taller than our house with branches overhanging our garage. Our corner plot means the end of their garden backs on to ours, so their house is a long way off and we don't know them to speak to.

An architect who came to quote for plans, said we may need pile or raft foundations - unless something could be done about the trees. 6 months ago, we wrote to our neighbours offering to pay to remove the trees and make good. They said they needed to think about it, but we've not heard back from them.

Now we're thinking that removing the trees won't solve the problem anyway as the ground will take a long time to settle. We just want to crack on with this project ASAP, so we're thinking the foundation will have to be extra deep, pile or raft.

[/FONT]

Doozergirl

Speak to a structural engineer. They can design appropriate foundations and advise on the trees.

Chrishazle

Our house was built fairly close to a very large oak tree that is within our property boundary. Before planning consent could be obtained, the owners (it was a self build plot) had to have a full foundation study undertaken - we have the documents as they were part of the documentation package that came with the house! On the tree side of the house, the foundations had to be 3m deep, shallowing to 1.5m on the opposite side.

Chanes

Chrishazle wrote: »

Our house was built fairly close to a very large oak tree that is within our property boundary. Before planning consent could be obtained, the owners (it was a self build plot) had to have a full foundation study undertaken - we have the documents as they were part of the documentation package that came with the house! On the tree side of the house, the foundations had to be 3m deep, shallowing to 1.5m on the opposite side.

How close is fairly close? I remember learning that each type of tree had an ideal minimum distance from a property. Oak was a serious prospect because it had one of the furthest distances. Tree aren't a problem if the foundations are good (as you can certify) Newer houses are less at risk from tree roots because of the foundations that are built.

Furts

Piles sound fine, but a raft would be a no go area. Be ultra careful if you are receiving such advice. Indeed I suspect your Architect is not qualified to give that advice but only you know what competence the person has.

In the interests of simplicity and cost you would be wise to push for a conventional foundation design. However this does not resolve your tree issues. The fact that they overhang your garage means it will be impossible to build without removing them at least as far as the boundary fence. Remember you need space for scaffolding in order to build your extension and this scaffolding cannot be located amongst trees!

moneyistooshorttomention

The plus side is that people are legally allowed to trim back any trees overhanging their property to the boundary line - provided they hand the trimmings back to the owner.

The other factor here is the number of insurance companies that include a question about how close the nearest tree is to ones house in their questionnaire assessing whether to insure you/how much to charge. So - it's possible you may get a "computer says no" response - rather than a commonsense "Please tell us the exact facts about your particular house" response and have problems getting insurance cover as a consequence.

****************

and...yes....I've been watching those recent tv programmes about designer houses built literally right amongst trees and decided, as a consequence, that I personally am no longer automatically against having a house bang near a tree/trees and that it depends entirely on what the foundations are like (and how well fixed in the ground those trees are v. the strength of nearby winds).

brightontraveller

· [FONT=&amp]Did it significantly add to the overall costs? (Can easily double cost of foundations, [/FONT]aboriculturalist fee’s, higher engineers, architect fee’s, extra access cost (over underground root systems etc )
· [FONT=&amp]Did you find builders were willing to take this on?( Plenty will most of them shouldn’t )[/FONT]
· [FONT=&amp]Did you face any other problems, long-term issues, hidden costs? ([/FONT]crown reduction, disease to tree’s, higher maintenance leaves in guttering, higher insurance etc)
· [FONT=&amp]If the build work damages the roots, could the trees to become dangerous? Would we be liable? (Tricky it comes down to contract, onus of proof, limitations on time, eventually it will be solely your responsibility) [/FONT]
[FONT=&amp]Anything else we need to think about? (Moving is often cheaper) [/FONT]

Chanes

Furts wrote: »

Piles sound fine, but a raft would be a no go area. Be ultra careful if you are receiving such advice. Indeed I suspect your Architect is not qualified to give that advice but only you know what competence the person has.

In the interests of simplicity and cost you would be wise to push for a conventional foundation design. However this does not resolve your tree issues. The fact that they overhang your garage means it will be impossible to build without removing them at least as far as the boundary fence. Remember you need space for scaffolding in order to build your extension and this scaffolding cannot be located amongst trees!

I thought raft foundations were safe near trees?

http://www.darlington.gov.uk/media/121421/Foundations-Close-to-Trees.pdf

Clive_Woody

There are several very big oaks near our house and apparently we have medium shrinkage clay soil. We had an extension built a couple of years ago and had to have 2m deep foundations. We needed a mini-digger to dig the foundations and several lorry loads of concrete (there was also a pumping lorry involved to get the concrete round the back of the house).

We used an architect to do the plans and also had an engineer do various calculations for moving beams and widening openings. I can't recall who came up with the decision on 2m foundations but the buildings inspector was happy enough with this.

Furts

Chanes wrote: »

I thought raft foundations were safe near trees?

http://www.darlington.gov.uk/media/121421/Foundations-Close-to-Trees.pdf

Not so for house extensions. For a one off complete unit a raft can perform provided it is correctly built.

Your link uses the weasle words "may" and "such as" to protect the authors here.

Chanes

Furts wrote: »

Not so for house extensions. For a one off complete unit a raft can perform provided it is correctly built.

Your link uses the weasle words "may" and "such as" to protect the authors here.

Ah, I see the reasoning; it has to be a continuous slab, not two separate slabs.