PLANNING INDICATIONS
7.5 Noise as a subject of weighing in city planning

If urban land-use planning wants to fulfil the requirements of noise precaution in planning, the knowledge of noise-related interdependencies must be systematically translated into practice. Their implementation is initially limited to the legal instruments laid down in the Federal Building Code and restricted to the particular designated area, including the representations of the land-use plan (e.g. route planning), the legally binding designations of the development plan, the project completion plan and the agreements of the urban development contract. Another basis for noise-related planning are noise action plans; they are at the same time a helpful strategic sectoral planning instrument.

Noise protection is therefore one important aspect among the "requirements of environmental protection" mentioned in the Federal Building Code to which the principle of weighing according to § 1 para. 6 of the Federal Building Code is to be applied in relation to other, potentially competing interests. As there is no designation which, on its own, could guarantee sufficient noise control, it is essential that the sum of representations and designations accounts for the noise-related requirements. What needs to be considered, however, is the principle laid down in § 9 para. 1 of the Federal Building Code, claiming that all designations need to be based on urban development requirements.

In the drawing up of a legally binding land-use plan, it does not suffice to include appropriate noise abatement measures, but comprehensible reasons must be given for the selection of these measures and designations. Please note that the required noise abatement regulations must and can often not only be prescribed in the legally binding land-use plan alone but that further pollution control rights requirements must be met. What counts here is the polluter pays principle, other than in building law. This means that if an immission conflict is caused by planning itself, e.g. in the case of an approaching residential development, the municipality must ensure by means of appropriate planning methods that the polluter pays principle pursuant to pollution control rights has no negative effects on the noise emitter/operator of the installation (BUNZEL, 1997, 4.1 Building law).

This is why the argumentation of a legally binding land-use plan must consider the following questions:

• Which noise emitters have an impact on the planning area/designated area?
• How can the resulting noise situation be assessed?
• Which noise sources are changed or must be added due to planning?
• Are there acoustic characteristics, like short-term level peaks or branch-specific features, which must be considered?
• Do the conditions relevant for sound propagation change due to planning?
• Which impacts do these changes have in the planning area, which noise abatement measures are possible and which measures are taken in particular?
• What is the sound level prognosis for the planning area in consideration of the applied measures and how can the intended situation be assessed?
• Are there alternative measures in order to improve the result within the meaning of § 50 of the Federal Immission Control Act, regulating that harmful environmental effects must be kept to a minimum?
• Are there any disadvantages for adjacent territories as a result of planning?

Information from official sectoral planning provisions (noise abatement/noise action plan) may help to answer these questions; calculation foundations or forecast data can be collected or complete expert opinions ordered if necessary.

Urban land-use planning is not only concerned with the prevention of harmful effects on the environment (hazards, significant disadvantages or disturbances), it shall rather "contribute to securing a more humane environment and to protecting and developing the basic conditions for natural life" (§1 para. 5 no. 1 of the Federal Building Code). So its purpose is also to take precautions against hazards and to prevent perceivable risks. Furthermore, the question of what is "relevant" has no scientific evaluation basis, i.e. that the decision is based on values and priorities. This makes an assessment complicated and puts high demands on the assessment foundations. Relevant technical regulations, ordinances and acts are of special importance here, especially official and unofficial sectoral planning provisions, even if they often provide no binding definitions and requirements. In this case, a reasonable degree of disturbance must be determined on the basis of individual circumstances, reference values or by consulting a particular expert opinion.

Sometimes it may suffice to make an assessment only for the critical parts of a planning area. But the cases where the consideration of the noise aspect is completely irrelevant will be rare. What must be considered in very quiet areas is the fact that even relatively slight traffic increases or new noise sources can change the situation sustainably. And new, so far unfamiliar noises particularly stand out.

Excess planning in particularly noisy urban development situations which require acoustic redevelopment can definitely improve the situation, but this does still not fulfil the requirements of due noise protection. Planners must nevertheless treat the above-mentioned questions for an appropriate weighing according to the initiator principle.

The most important basis for the handling of noise conflicts in the context of a development plan procedure are the "acoustic orientation values" designated within Supplement 1 to DIN 18005-1 (Noise abatement in town planning). Planners must deal with the question of which measures can be taken in order to meet the sound level values or, for a minimization of the harmful environmental effects, stay below them. The "orientation values" describe the intended target values from a noise control perspective and can be used to this effect by the local authorities in the course of the weighing process. More stringent technical or urban development arguments are expected, however, if the values are significantly exceeded.

Territorial protection and therefore active noise abatement measures must have priority; in already developed areas, however, the range of measures is usually more restricted than in newly planned areas for example. Here the spatial distribution and the zoning of permitted uses are the central starting point for efficient noise abatement. Designations and earmarkings within the legally binding land-use plan can additionally provide for an arrangement and construction of the buildings right from the beginning, protecting important free spaces or at least the interior of the buildings from noise.

The Federal Building Code (§ 9 para. 5 no.1) allows to anchor the necessity of constructional or passive sound insulation measures in the affected areas within the legally binding land-use plan or to designate such measures according to § 9 para. 1 no. 24 of the Federal Building Code. The required measures at buildings (e.g. soundproof windows) shall be determined and verified according to DIN 4109 or VDI 2719.

But as such measures can create indoor environment quality only to a limited degree, the earmarking for noise abatement must by no means degenerate into a universal remedy for all situations in which mostly very high noise barriers should rather be avoided or cannot be established due to a lack of space in already developed areas. For an appropriate weighing of this problem, planners must thoroughly concern themselves with the question of whether there are other urban development concepts or road traffic measures to produce relief.

The Traffic Noise Ordinance (16th Federal Immission Control Ordinance), which is applied to the construction and major alteration of transport routes, represents a further aspect relevant for the weighing process in city planning. This ordinance and the immission limit values determined therein are valid regardless of the type of procedure selected for traffic planning and therefore also in connection with legally binding land-use plans, provided that they contain the construction and alteration of a transport route. This determines both the requirements for noise abatement measures in the context of a legally binding land-use plan and the method of calculation which is to be selected in the case of a new road for example.

In the context of urban land-use planning, the requirements of the 16th Federal Immission Control Ordinance represent minimum requirements for the protection from "harmful environmental effects", whose non-adherence may necessitate noise abatement measures. The immission limit values of the 16th Federal Immission Control Ordinance are therefore not qualified for representing an urban development principle within the meaning of the targets specified in DIN 18005-1 (principle of precaution). The contents of the 16th Federal Immission Control Ordinance are significant for the weighing of noise abatement measures as the immission limit values therein represent another threshold, i.e. the limit of reasonableness without further provisions, which is reached when the "acoustic orientation values" within Supplement 1 to DIN 18005-1 are exceeded. The range between the acoustic orientation values according to DIN 18005-1 Supplement 1, which must be possibly met pursuant to the polluter pays principle, on the one hand and the immission limit values according to the 16th Federal Immission Control Ordinance on the other hand provides the municipalities, as long as the reasons are plausible, with enough scope to fix the required presentations and designations in many cases where an intended residential development comes close to existing transport routes due to a lack of appropriate areas.

It is also principally conceivable that limit values are exceeded as the scope of the 16th Federal Immission Control Ordinance does not cover the case of a development approaching an existing road, and there is a wide range of possibilities for city planning. In the case of a newly planned residential area, only special reasons could provide the arguments for a noise exposure beyond the limits of "harmful environmental effects" which could withstand the process of appropriate weighing. If the limit values according to the 16th Federal Immission Control Ordinance are exceeded in the context of a planned road in the proximity of a residential area, a financial compensation is made pursuant to § 42 of the Federal Immission Control Act.

As municipalities must draw up noise action plans, which shall control "noise issues and effects" (§ 47d para. 1 of the Federal Immission Control Act) according to the EU Directive on Environmental Noise (2002/49/EC Directive) and to Part VI of the Federal Immission Control Act (§§ 47a to 47f Noise abatement planning), it would be difficult to accept noise situations as a consequence of new planning provisions, which should be assigned to the catalogue of acoustic restructuring cases on municipal territory already in the planning stage due to the occurrence of harmful effects on the environment.

The available planning options for noise abatement should be fully used for the purpose of sustainable urban land-use planning and therefore settlement development. However, the best possible noise protection is still noise prevention or noise reduction at the point of origin, even if it is true that not all life-related activities producing noise can be avoided or prohibited.