The Façade Noise Map

Façade Noise Maps - What for?

The Façade Noise Map arranges receivers to be calculated on all façades of residential buildings. Receivers can be placed for each floor, or at a single height from the ground. The results are used for two main purposes; to show the noise levels at buildings and to generate the data for the END noise statistics where the number of exposed people are tallied. The conventional Façade Noise Map includes the capabilities to shade a facade point by point, to shade the façade in accordance to the maximum noise level found on the façade, or to color the entire building in the color of the highest noise level found anywhere on the building.

The Façade Noise Map can be displayed as a top-view as in the top picture, or as a 3D model as in the lower picture. Formatting options allow buildings to be displayed with the calculation points superimposed, or the entire façade shaded according to a user defined scale. For the display of single receivers, it is possible to select different icons to distinguish between noise levels exceeding the noise limit and noise levels that are acceptable.

The Prep-Work

In the Geo-Database, the buildings for which a Façade Noise Map shall be generated must be activated and the façades to be calculated must be marked. It is possible to mark all building façades or to select/de-select individual façades. The buildings must also have certain parameters defined. The number of floors is crucial, as well as the height from floor to floor. These parameters are needed to locate the receivers.

If you want to use the Façade Noise Map to gather noise exposure statistics, you must assign the number of residents to the building. This can be done on a building by building individual assignment or by assigning residents in the Attribute Explorer.

If individual resident numbers aren't available, SoundPLAN can distribute the number of residents on the basis of the usage area, where the number of residents are assigned to areas of similar building use. The numbers can come from sources such as the voting register or city databases. SoundPLAN's GeoDatabase has

   GeoTools/More Building Tools/Distribute occupants     

to distribute the inhabitants from the (marked) usage areas to the residential buildings enclosed in them. The program calculates the total number of square meters of residential living space in the area (footprint of the building times the number of floors assigned to the building) and distributes the number of residents from the usage area evenly among them. The last screenshot in this section shows the result of the assignment where the population numbers and the square meters per resident are listed for each usage area.

Another method is marking the buildings and use

   GeoTool/Prepare Buildings

which allows the user to assign a number of residents directly to the building depending on the square meters of residential space each resident has to their disposal.

The data of the buildings, along with the 3D terrain model and the noise sources, make up the noise model. Information must be saved in a Situation that the Calculation Core processes. The Calculation Core needs to know where the Façade Noise Map is to be calculated. For this purpose, an area we call the calculation area is required. All buildings within this area will be included in the Façade Noise Map. SoundPLAN can handle an unlimited number of noise maps that can be included in a Façade Noise Map Graphics or be used for the calculation of the Spreadsheet.

How to assess the Number of Residents

In order for SoundPLAN to tally the residents exposed to high noise levels, the entire town must be defined as a usage area or divide it into multiple usage areas (this was already helpful to define the residents per building). It is wise to generate usage areas with similar building structures and character (similar number of floors, similar number of residents per apartment...). The SoundPLAN Spreadsheet can then deliver the EU statistics on the basis of the usage areas.

At this point it is assumed that the number of residents have been assigned for each building, and the number of dwellings if that information is desired. A Façade Noise Map is calculated on the basis of the statistical noise exposure evaluation.


Façade Noise Map Calculation Options

The user needs to decide where the receivers are to be located on the map. It is possible to have a single receiver placed in the middle of the façade, or two receivers, or just select a spacing between the receivers. If the Façade Noise Map is carried out in strict compliance to the END, a second receiver should be calculated 2 meters in front of the façade, This, however, will double the calculation time. As the initial noise mapping was to be carried out at a single height of 4 meters above ground, there is also the option to not calculate floor by floor and instead simply locate all receivers at the 4 meter level.

Additional settings define how the calculation is to be done. If the search range is defined by the facade, noise from the backside of the building will be ignored. First order reflection on the "own" building can also be suppressed (see façade correction in the hotline desk section).

A Façade Noise Map can save more than the noise levels, but this has to be done with caution as city wide noise maps have huge file sizes.

Getting the END Statistics

The easiest way to get the END statistics is to load a Situation and a calculated Façade Noise Map in the format of the EU-Buildings directly into the Graphics. The raw-unformatted form of this can be seen to the left. The buildings are shaded in accordance to the standard EU color scale, and a box with the statistics for the entire town (or calculation area) is prepared from the data contained in the situation and the Façade Noise Map. Simple procedure are sufficient for most cases.

Display Options

When a Façade Noise Map is started in the Graphics, the user can select the time slice (day or evening or night or Lden...) and the floor the noise map will display when it is in 2D. Alternatively, the loudest value for each facade receiver can be presented. In 3D, all floors can be visible simultaneously. The scale for noise maps is also users controlled.

With the graphics Object Setup you can control the appearance of the Façade Noise Map. Decide if the noise map is going to be in 2D or 3D.

If 3D, choose between painting the facade the color of the noise scale or displaying individual receivers as solid objects representing the levels at the facade.

If 2D, there are individual symbols for the calculated receivers. They can be filled in scale colors or there can be one symbol showing the noise levels in compliance and another showing conflicts. The noise levels themselves can be printed in the middle of the facade noise symbol or be omitted. If the scale increases, the visibility of individual symbols may be problematic. If so, it is advisable to color entire facades in accordance to the maximum noise level found on the facade, or to color the entire building in accordance to the scale colors. Combinations of the different display modes are also possible.


Façade Noise Map in 3D

The Facade Noise Map can be used within the 3D Graphics to produce the receivers as a solid object such as the high-rises to the left, or it can color the entire facade as shown above for the Facade Correction. Simply select different options in the Object Setup!

Facade Noise Maps can be combined with Cross-Sectional noise maps or Grid Noise Maps or Meshed Maps to form maps depicting the complete noise situation.

Calculations with Façade Noise Maps

Just like Grid Noise Maps, it is possible to do arithmetic calculations with Facade Noise Map. This makes it possible to show differences between analysis and prognosis. Once can see where noise levels increase or decrease. This is only possible with the flexible concept of the SoundPLAN Facade Noise Maps which allow a limitless number of noise maps and can address each of them individually . The formulas allow the user to calculate the difference between the maps or add noise maps from road noise to maps from railway or industry to form a comprehensive noise map. It is also possible to add a constant background noise level.

The Meshed Map - a Cousin of the Façade Noise Map

The Meshed Noise Map (available when Grid Noise Map and Facade Noise Map are part of a license) uses the internal storage mechanism of the Facade Noise Map. This calculates the initial noise map and  then produces multiple noise maps as a frequency by frequency breakdown as seen to the left.

The Façade Noise Map and the SoundPLAN Spreadsheet

If you are requested to produce more in-depth results than the Graphics statistics supplies, SoundPLAN has the ultimate flexibility available with its SoundPLAN Spreadsheet. This spreadsheet functions similarly to other spreadsheets but has several distinctive advantages. All SoundPLAN internal data are directly available, it is possible to generate columns for result data and to import data from other Facade Noise Maps into an existing building account. The spreadsheet has provisions to make separate/compound statistics for road traffic, railway traffic, aircraft and industry, and then tally the sum of the infringements and the total of the noise affected persons. It is also possible to host data for multiple scenarios in the spreadsheet and to create columns with the change between the analysis and the prognosis.

The spreadsheet has multiple pre-defined variants. One allows access to the calculation results of the Facade Noise Map, one is for an account of all buildings and another is focused on usage areas. Information from one spreadsheet can be imported into another spreadsheet type. The Area Table can also be displayed in the Graphics as seen to the left.

All data in the SoundPLAN Spreadsheet are internal, so they update automatically when new calculation results are available, eliminating the need to export from SoundPLAN and then re-import into an outside spreadsheet or a GIS system.

One example showing how practical this spreadsheet is - especially for big areas, is to relate the total number of noise infringements to the total area and thus map the total infringements per square kilometer. In the Area table of the Spreadsheet, the building statistics has been imported to show the number people exposed to more than 65 dB. The area table supplies the size of the usage areas, and an extra column with the formula to divide the number of people by the size of the area yields the number of people per square meter. Multiplied by 1000² shows the number of people with exposure greater than 65 dB per square kilometer. This Area table as a conflict map is directly imported into the Graphics to present the areas with the number of noise impacted persons per square kilometer. It is presented with a user defined scale, shown here in different shades of blue. In addition to the areas being shaded to reflect the occupants/km², the buildings are colored in accordance to the noise scale.

Copyright 2014 SoundPLAN international LLC, Shelton, WA 98584, USA