I don't know about technical or required distance, but we have an extremely large 100 year old maple in front of our house that we had to switch garage side for. This was a bummer because it impacted our layout and windows for south facing natural light! We have about 30 feet between tree and our front porch. Our village was also careful to require 'tree protection'. Our builder told us that we should not be concerned about our plumbing lines being impacted by roots due to the material. My parents live on a wooded lot and it seems like they have plenty of trees within 20'.

Cant be closer than 5' in our county.

Other than local community restrictions, it very much depends on the species of tree, and how far you are willing to push your luck.

As a rule of thumb, most trees have as much (and a similar configuration) root below ground as branches above ground, but the lateral root-spread varies from drip-line to treble the dripline's diameter. So if you have a fullgrown ten-foot holly with an 8'-diameter dripline, it is reasonably safe for both foundation and tree to build about 5' from the trunk. However, a maple (noted for their spreading and invasive root systems) really should be kept at least 50' from the foundation and farther is better. BTW, willows are notable for invading the water and sewer pipes -- I know of one which extended its roots over 100' to curl around (and eventually into) the water supply pipes.

In loose generalization, one can safely build up to the expected mature dripline of any tree, without problem. Note that it is the *mature* dripline which counts...

That'd be too close for my comfort. Trees get damaged during construction. Their root systems are greatly compromised not only by the digging for the foundation, but just generally from the equipment running over the roots on a regular basis and from any dirt that has been disturbed around them (either adding or removing). If you plan on maintaining those trees, you will have to take drastic steps in order to keep them healthy throughout the build - fencing, signs, etc to keep workers and equipment away. I'd use the dripline approach to determine where the fencing should go. If you do not take steps to protect the trees, they will die and you will be taking them down in the next couple of years.

We pretty much cleared our lot 80' + in all directions, except for the one tree that was the reason we purchased our property (it adds to the southerness (word??) of our home). We employed a professional arborist to come out before the lot was cleared and help us establish a perimeter around the tree as a safety zone. We then put up semi-permanent fencing with flagging and signs (in English and Spanish) which stayed in place throughout our entire build. We also made sure that we were on site whenever any grading or trenching was scheduled to occur. The tree made it through unscathed, but it would definitely not have done so if we had not been diligent in our efforts to keep it.

Keep them at least 20-30 feet away depending on the species. Get rid of any now that look like they may cause trouble down the road. You don't want any that are leaning toward your house even if they look good. Ice and storms can bring down a healthy tree into your house. I like to keep as many as possible too, but you also have to consider equipment getting around your house.

We have several large oak trees within 10-12 feet of the home and they lived through the construction and are thriving several years later. I am glad we saved them.

Think also of leaves...and gutters. We're willing to pay the (gutter cleaning) price of having a huge sycamore shade the south side of our screened porch. Darn tree doesn't leaf until June and doesn't drop its leaves until December! They're blowing across the snow right now. But it's great all summer.

We just removed two big ashes from our front lawn -- messy and increasingly falling prey to Emerald Ash Borer in our area. Awaiting *big* bill.

We have 3 birch trees that are that close and they've made it, it's been over 4 years now. DH roped off a large area and allowed no excavation or driving inside the roped off area.

The drip line of the tree is the requirement. Keeping in mind that there are some trees that can not handle compacton of the soil at all...like post oak and burr oak. While they will not die immediately they will sicken and die over the years. You can add a requirement to the builders contract that any trees damaged (limbs, etc.) during construction are to be replaced.

We built around a tree -- it is less than two feet from our porch, which we put up on piers to maintain as much root as possible. We'll see if the tree survives, but i consider it worth the risk.

If I were in your situation, I would leave them all, fence them off, tell the builders not to disturb the fence, and hope for the best. If you have to remove one in a few years, well, it's not going to be much more expensive than removing it now.

There are extensive rules here with regard to tree protection during construction. See page 3 of the linked document for required tree protection zones.

Here is a link that might be useful: Tree Protection

I'd be willing to bet that a lot of people in the north east wish that they didn't have trees so close to their house after that big ice storm!

I hate big trees near our home.

But municipal restrictions here prohibit you from even cutting down trees on your own property without permission--and that is rarely granted unless your new home is to be located where the tree is. And you pay a $100-$300 per tree charge. If you cut without permission, you'll be charged up to several thousand dollars per tree. (By contrast, the City itself has removed hundreds of trees at once with no charge when they've built municipal housing or rejigged park space.)

As a consequence, builders routinely leave trees in the middle of driveways, hanging perilously close to porches and so forth.

Here is a link that might be useful: City of Toronto Private Tree By-Law

We have overhead utilities lines running by our properties. The co-op now and then cruises around marking "dangerous tress" concerning those lines. On the latest campaign over the summer, none of our trees were marked. If they fall trees on your property, you have the option of keeping them for firewod. Getting towards the fall and the end of tree cutting season, they convienently took another "survey" of the area and cut down six of our trees and didn't bother leaving us the trees for firewood, which in writing was originally agreed should they determine any trees would be cut down. When we approached them about it, they said there was nothing they would do to make up for the lack of leaving the trees for firewood despite us being pissed about them removing the trees. They were obviously digging up more work for themselves as it was late in the season. Nice, eh?