Hi Emilie,

There is no regulation for public spaces (streets and squares) in France, just a practice : the distance between trees and buildings is recommended to be more than h/2, h being the height of trees.

I'm also interested in knowing the uses or regulations in other countries.

Marjorie

Hi Marjorie,

thank you for these new elements. I have found some laws about distance of trees from fences for private gardens and tree management rules for public spaces in France. This h/2 ratio is worthwhile.

Other countries ?

Emilie

Hello, there is no specific regulation in Serbia. But reality is to use half of diameter of crown in third age class of species and in some cases root diameter also must be added. Many planted too close to buildings and gave wrong distances. I had plans to accumulate all research we made and to start making list with best distances. For example Tilia grandifolia and T. argentea 10 m, Juglans sp. 10 m, Platanus acerifolia 9-12 m, Betula verrucosa 7-9 m. and etc. Many fruits could go on 5-7 m.

Plan was to do same with distances in allies but I had to stop such work and delay for later when organisation of work on my job and wages become better. Maybe in 2 years I manage to make list you need. But suggestion is - do not use only diameter of crown when trees are old. Use also root diameter and it's behave because in case of Juglans you may be surprised to see roots breaching in sleeping room. Height is not relevant enough as constant. Diameter of crown is a bit safer but for each case you will need more trees to measure for making decision. Trust me ;) these are results of 14 years watching trees.

I had to edit answer because I did not found option to add new one.

Question about risk for pipes is good. Populus sp. can breach in buildings trough pipes if it is just on 3 m away from building. That species does need height to be used as measure for distances, and in it's case diameter of crown is not good to be used. But I did not had chances to measure relation. No worries it is not half of height. I think it would be closer to 1/5-1/4 of height (Populus can reach above 30 m in towns). Roots grow around pipes and sooner or later they break them and start developing inside. It was another question we tried to watch on field but did not had chances to make exact conclusions because we do not have ways to scan roots. Such machine exist but we do not have it normally. It is project for Universities I think and not for communal service where I work. Maybe some University could help you with those data.

About shading roofs and fasades - you can't avoid. It can be done, but then you will stay without 30-40 % of possible green surfaces. It would not be possible to avoid in narrow streets. Wise is to plan well and to avoid as much as possible. If you can limit shading on max 10% you did good job. But remember distances all are talking about are for mature trees. 

We have continental climate with adds of marine climate. Sorry can't translate better. I am in Vojvodina. Changes went towards warmer summers, long dry periods, lack of or reduced spring and autumn, insufficient snow and higher temperatures during winter. 

Hope this helps a bit and good luck :) 

Thank you very much Natasa Spica for your expertise. You provided great elements. In France, we have categories of trees ranged by their height only for each type of roads and avenues. Planted street trees are not taller than buildings (if it is the case they are cutted) and placed at least from 3 meters for medium size (as species you cited) to at least 5 meters for the largest boulevards, avenues and higher trees. What about shading of trees in roofs in Serbia ? Here, the distance prevent the shade on roofs but the shade can be large in walls.

Please forgive for so many edits of my answer. I really did not seen option to add new answer so I missed your respond :) 

5 m is not enough for many species Emilie. Distances must be chosen according maximal growth that plants can reach in urban areas. That growth is not always reduced if you compare with forests. Plants will only live shorter then in forest, but they will have chance to develop till almost full size. This area is researched really low. Many waste time on repeating same researches instead finding detailed answers on questions you asked. I hope it will change.

About shading buildings, it is not possible to avoid. problem is big because people get psichological consequences due to lack of light. I was thinking a lot about that problem and watching ways how to solve. Solution may be found in reducing density of crown, by cutting inside branches. It will also create some problems (insects, fungy, and etc.) but if job is done well solution could be acceptable. This approach could be used for most original species.

If there are species that could be used for specific narrow streets then they are best option. In many streets we can't avoid shading of walls. Job of landscape architect is to find those solutions. Many simply do not plant anything and that depends from type of building. Rules for that exist in core of designer part of studies. I can't list them, because it was long time ago and I also added some rules from other professions. I forgot how we called them, sorry :(

But decision what to plant is not easy. I finished University many years ago and I never got any update about best distances. That is why I started changing old list I got and replacing them when ever I remember with new distances I got as result of measuring on field.

Emilie :) Linkedid and Online seminars will help you with many answers you search ;) :) I like these most http://gibneyce.com/ 

Great website ! Thank you Natasa, I will study it.

I just noticed the above message. Thank you Natasa, the choice of species according to the urban form is pointed as crucial to limit management as cutting. I'm surprised that urban trees can reach a full size, good to know. I hope that your project on improving the knowledge about trees will succeed.

I'm not a landscape architect, so I can't address the specific design practices common in the US. I will say that in Texas it is very difficult to get the trees close enough to the structure to provide beneficial shading (heat rejection) during the summer as the afternoon sun angles are too high. As for legislation, that is typically determined at the level of the local municipality (city or town). In my experience, municipal tree preservation ordinances have only become relatively common in the last 10 years. Prior to that, the property owner could do just about anything they wanted when demolishing an old structure or constructing a new one. It was a common practice to bulldoze the entire site, including significant trees, even ones with historic significance.

Wonderful point Sam, specially about behave of others towards trees when they are reconstructing something. We also have similar problems, but our legislation did demanded pre-project documentation. In past 10-15 years it is not respected, but it exist in main Law for construction and etc. Many countries probably have that Law. They do exist but are on level of state. Each town only adds decisions as extra if something needs to be regulated. Many things are regulated trough planning rules in institutions for global planning of town development, like town Urbanization institution. Some towns adjusted rulers and if some one wants to build building for more people on place where only 1 family lived (change from P+1 to P+3 or bigger), then they must move construction line 2-5 m away from regulation line, or something like that. All towns did not implemented those changes and they will face with problem - loss of trees. Investor does not lose much because he will anyway charge extra from selling way too many apartments instead having only 1 or 2. Problem is greed - they want it all. Another regulation is - if some one is building on 100% of surface, then he must buy parcel nearby and make it as park. It is not exactly familiar to me because I am not working in Urbanism, but they will tell if some one ask them. Laws exist, some act and adjust them with changes or new trends. There is proposal of new Law in my country that deals with everything that concerns green surfaces, but it is not accepted jet. I heard that some other countries have firm laws, specially Austria and Germany. But did not researched it..

About Texas :D yes it is hot there. But ways exist always. Choice of species is best to start, then way how to water and when. You have enough space there, so pooling back building line would help. You will probably need 2 lines of trees in alley, with 2 species. Smaller one closer to buildings and bigger close to road. Maybe that would protect bigger one and make shade faster for later future. Also to plant them bellow normal height of surface so you can save up some water and drain all water if it fells to trees, instead wasting it on pedestrian or street. Just suggesting, we have different climate here ;)

Thank you Sam Watkins and Natasa Spica for these insteresting views of distinct parts of world. Trees are poorly protected in cities. In brief, the right species in the right place appears to be a big deal in the future while conflicting interests are numerous.

I have seen guidance for trees to be kept clear above a vertical angle of 45 degrees from the bottom of the house perimeter - keeps the green outlook meanwhile allowing solar penetration to the built form and to keep the house cladding dry and able to be maintained. Discretionary use of deciduous trees for solar shading in summer i.e. North and west in the southern hemisphere - south for the northern hemisphere

Thank you Renelle Gronert for your help. I have found some requirements specifications about street trees imposing a minimum distance from balconies or windows of 1.5 m to the crown in order to avoid excessive shading and facilitate the long-term management, so it is quite consistent with your guidance for trees. You mentioned the solar shading in summer, do you think it is considered as a priority in your place by the city council ? Is there any reference about it in documents related to local rules of tree management ?