Chapter 786) Which Provides That No Tenement House of Third Class

construction shall be erected nearer than 5 feet to adjoining lot line; but it may be constructed to the lot line if protected by a fire wall. A provision found in several codes limits the size only of tenement houses and apartment houses by specifying the proportion of lot which may be built upon, varying in the case of a corner lot from 75 per cent to 95 per cent, and in the case of an interior lot from 60 per cent to 80 per cent. The building code of Baltimore provides that there shall not be less than 20 feet between frame buildings, and no other building of any kind shall be built within 20 feet of any existing frame building on the next lot.

A bill presented to the legislature of the state of Washington in 1911 proposed a considerable extension of the right to regulate the use of private property by requiring that in every newly developed area containing five acres or more there should be a reservation of 10 per cent of the land for public open space, after deducting such land as would be required for street purposes. It is clear that a most liberal interpretation of the police power would not justify a regulation which in reality amounts to a taking of private property without compensation.

That the courts will not sanction any and every legislative regulation is clear in several decisions in which the validity of ordinances specifying the degree of intensity with which property should be used have been successfully attacked. The supreme court of California in 1910, in the case of Wilson et al. vs. City of Alhambra, 158 Cal. 430, enjoined the enforcing of an ordinance which compelled the owner of six acres of land to lay out a street over his land not less than 50 feet wide. The street in this case was an extension of an existing street which was only 40 feet wide. The court held merely that to require an owner to build a street wider than many of the existing streets in the town was an unreasonable exercise of the police power.

2. DIFFERENTIATED ZONES OF HEIGHT LIMITATION

A most important question to the city planner is to what extent American municipalities may, in the exercise of the police power, copy regulations common in German cities and prescribe different building regulations for different districts of a city. The principle is not new in the United States. Many cities have at least two building districts from one of which non-fireproof buildings are excluded. The constitutionality of fire zone ordinances is universally upheld.

The building regulations in the city of Köln are taken as illustrating the German system, because they are simple compared with the regulations in some other German cities. The city is divided into four building districts, the first of which comprises the area inside the old city walls and contains the central business district. In this district buildings may have four stories and a height of 66½ feet, and may occupy 75 per cent of an inner lot and 80 per cent of a corner lot. The second district is made up of the more closely built suburbs of urban character, and here buildings may have not more than three stories, a height of not more than 52½ feet, and may occupy 75 per cent of the lot if the building does not exceed 26 feet in height, but only 65 per cent otherwise. In the third district the buildings are limited to two stories, a height of 38 feet, and may occupy 65 per cent of the lot if they do not exceed 20 feet in height, and only 50 per cent otherwise. The fourth district is devoted to detached buildings or villas of two stories and 52½ feet in height. Only 40 per cent of the site may be covered by buildings, or 50 per cent if the site is a corner lot. In this district also there must be at least 33 feet between buildings and 16½ feet from the boundary of the lots to the buildings. Reference to the map of Köln will show that the districts have been so located that just outside the old walls of the city is a broad band of open villa buildings, and that the more closely built suburban districts are also separated by the same open style of construction.

An approach to the German system is found in Boston and in Washington. The Massachusetts commission on height of buildings authorized under