In preparing decisions in all fields of spatial and sectoral planning, interests typically need to be weighed. This is a key requirement in planning for the benefit of society under the rule of law. A complex theoretical framework has consequently been developed to achieve this in applying building and sectoral planning law. The requirement to weigh interests in urban land-use planning is enshrined in the Federal Building Code. Conflicting public and private interests are to be weighed against each other and given fair consideration This places a duty on municipalities to ensure:
1. that interests are duly weighed,
2. that all matters warranting consideration are covered,
3. that there is no failure to appreciate the importance of public and private interests
4. that the balance achieved is proportionate to the objective importance of individual interests.
Within these limits a municipality is free to decide in favour of one interest and thus against another.