本文发表在 rolia.net 枫下论坛Trees are urban assets that grow in value over time and produce a wide range of economic benefits. Direct economic benefits received by each homeowner are usually associated with heating and cooling energy savings, and increased property value. Trees generate benefits for commercial sector, and retail business in particular. In addition, urban forestry has other significant indirect economic benefits associated with reduction in airborne emissions from mobile sources, and energy generating facilities due to lower peak energy demand. Other benefits include soil erosion control and lower storm water treatment costs.
Heating and cooling energy savings
Trees are "low tech" solution to energy conservation. Potential savings in residential building are higher than in commercial or institutional buildings. Large shade tree reduces air temperatures by about 5 to 10 degrees F and, when properly placed, can reduce summer cooling costs. Evergreens with dense, persistent leaves can be used to provide a windbreak, while deciduous tree allows the sun to warm a house in the winter.
Previous studies used building energy simulation programs that calculate the annual hourly heating and cooling energy use of a building based on the building characteristics, its operational schedules, and weather data.
We use the Chicago Urban Forest Climate Project as a case study to estimate potential residential cooling and heating energy savings in Rhode Island, given the similar level of mean air temperature (49.1 F in Chicago and 50.4 F in Providence) and the same annual wind speed of 10.4 miles per hour. Other factors affecting the amount and type of energy savings associated with trees are neglected.
A single 25-foot tree planted near the house to maximize wind breaking and shading effects, reduces annual heating and cooling costs by 2 to 4 percent, or $15 to $30. The total potential savings from planting a tree near each of 259,500 single-unit houses in Rhode Island amount for $3,892,557 – $7,785,115.
Street trees and other scattered trees in neighborhood can reduce wind speed by as much as 50% (Heisler, 1990). Lower wind speed minimizes the infiltration of outside air, which is beneficial during heating and cooling seasons. Computer simulations and building energy measurements indicate the windbreaks potential to reduce heating costs by 10-30%. This impact alone can lower home heating bills of an average household in Rhode Island by $70-210. Although trees planted along streets and in the parks do not offer direct shade to air-conditioned buildings in summer time, they exert an ambient cooling effect sufficient to have a substantial impact on smog reduction.
Increased property value
Properly placed and maintained trees increase the value of real estate in urban areas of Rhode Island and proceeds from property tax. Developers can maximize profits by retaining existing trees or replanting an urban forest after construction is completed.
According to previous studies in different parts of the USA, realtors assign 10-23% of value of a residence to the trees on property, while the buyers are willing to pay 3-7% more for residential properties with ample trees. Generally, current or potential residents of low price homes do not discern between the hardwoods and softwoods, as well as the location of trees on the lot. Tree size tends to affect the judgement of price for expensive homes. Small and medium-sized trees enhance the public's perception of real estate value. We assume that the presence of trees increases the sales price of a single-family house by 3-5% (Anderson and Cordell, 1988). Under this assumption, property price increase is equivalent to $4-6.65K per $ 133 K, the median value of owner-occupied housing units in Rhode Island (U.S. Census Bureau, 2000).
Trees also influence rental prices as they enhance landscape aesthetic and produce building shade: rental rates can increase by 7%. At the same time, plants as visual screens reduce rates by 7.5%. Therefore, proper location of trees is essential for enhancing the property value.
Benefits in retail environment
Urban trees enhance the economic stability by attracting business and tourists. Apartments and offices in treed areas have higher occupancy rates. Treed shopping districts are associated with higher quality, amenity and comfort. Contingent valuation surveys reveal the willingness to pay for products in the landscaped district to be 11% higher as compared to the no-tree district. The respondents assign higher prices for both convenience and specialty goods, which allows to perceive the trees as a significant "amenity margin". Consumers give 30% higher ratings to the quality of goods, and 80% higher amenity and comfort ratings for a tree lined sidewalk in the shopping area. The automobiles parked in the shade of the tree have the interior temperature 20 to 30 degrees F cooler than an automobile in the sun. This increases willingness to pay for parking, as well as the duration and frequency of visits, travel time and travel distance. Therefore, despite planting and maintenance costs, the trees provide indirect benefits to business.更多精彩文章及讨论，请光临枫下论坛 rolia.net
Heating and cooling energy savings
Trees are "low tech" solution to energy conservation. Potential savings in residential building are higher than in commercial or institutional buildings. Large shade tree reduces air temperatures by about 5 to 10 degrees F and, when properly placed, can reduce summer cooling costs. Evergreens with dense, persistent leaves can be used to provide a windbreak, while deciduous tree allows the sun to warm a house in the winter.
Previous studies used building energy simulation programs that calculate the annual hourly heating and cooling energy use of a building based on the building characteristics, its operational schedules, and weather data.
We use the Chicago Urban Forest Climate Project as a case study to estimate potential residential cooling and heating energy savings in Rhode Island, given the similar level of mean air temperature (49.1 F in Chicago and 50.4 F in Providence) and the same annual wind speed of 10.4 miles per hour. Other factors affecting the amount and type of energy savings associated with trees are neglected.
A single 25-foot tree planted near the house to maximize wind breaking and shading effects, reduces annual heating and cooling costs by 2 to 4 percent, or $15 to $30. The total potential savings from planting a tree near each of 259,500 single-unit houses in Rhode Island amount for $3,892,557 – $7,785,115.
Street trees and other scattered trees in neighborhood can reduce wind speed by as much as 50% (Heisler, 1990). Lower wind speed minimizes the infiltration of outside air, which is beneficial during heating and cooling seasons. Computer simulations and building energy measurements indicate the windbreaks potential to reduce heating costs by 10-30%. This impact alone can lower home heating bills of an average household in Rhode Island by $70-210. Although trees planted along streets and in the parks do not offer direct shade to air-conditioned buildings in summer time, they exert an ambient cooling effect sufficient to have a substantial impact on smog reduction.
Increased property value
Properly placed and maintained trees increase the value of real estate in urban areas of Rhode Island and proceeds from property tax. Developers can maximize profits by retaining existing trees or replanting an urban forest after construction is completed.
According to previous studies in different parts of the USA, realtors assign 10-23% of value of a residence to the trees on property, while the buyers are willing to pay 3-7% more for residential properties with ample trees. Generally, current or potential residents of low price homes do not discern between the hardwoods and softwoods, as well as the location of trees on the lot. Tree size tends to affect the judgement of price for expensive homes. Small and medium-sized trees enhance the public's perception of real estate value. We assume that the presence of trees increases the sales price of a single-family house by 3-5% (Anderson and Cordell, 1988). Under this assumption, property price increase is equivalent to $4-6.65K per $ 133 K, the median value of owner-occupied housing units in Rhode Island (U.S. Census Bureau, 2000).
Trees also influence rental prices as they enhance landscape aesthetic and produce building shade: rental rates can increase by 7%. At the same time, plants as visual screens reduce rates by 7.5%. Therefore, proper location of trees is essential for enhancing the property value.
Benefits in retail environment
Urban trees enhance the economic stability by attracting business and tourists. Apartments and offices in treed areas have higher occupancy rates. Treed shopping districts are associated with higher quality, amenity and comfort. Contingent valuation surveys reveal the willingness to pay for products in the landscaped district to be 11% higher as compared to the no-tree district. The respondents assign higher prices for both convenience and specialty goods, which allows to perceive the trees as a significant "amenity margin". Consumers give 30% higher ratings to the quality of goods, and 80% higher amenity and comfort ratings for a tree lined sidewalk in the shopping area. The automobiles parked in the shade of the tree have the interior temperature 20 to 30 degrees F cooler than an automobile in the sun. This increases willingness to pay for parking, as well as the duration and frequency of visits, travel time and travel distance. Therefore, despite planting and maintenance costs, the trees provide indirect benefits to business.更多精彩文章及讨论，请光临枫下论坛 rolia.net