This clause gives an excellent power to the sanitary authority, especially in older towns, to lay down improved building lines upon the plan of their town, and thus set back the line of buildings as opportunity offers. In assessing the value of compensation to be paid to the owner for setting back his property, the following points should be considered: (1.) The value of the area of the land given up to the public. (2.) The loss of available and useful space to the premises. (3.) If any use is made by the owner of the land given up to the public by constructing cellars underneath, the amount of compensation should be less. (4.) The amount the owner will have to expend to make good the sides of the neighbouring premises thus exposed by his setting back must be considered. A surveyor should be very careful to recollect if any building line has been laid down in any street when the plans of new buildings are deposited with him for approval. If these plans are approved without any notice being given to the owner to set back, it is questionable whether he can afterwards be called upon to do so.[132] (2.) _Removing Projections of Buildings._--The Towns Improvement Clauses Act 1847 made provision for setting back any house or building, or any part which projected beyond the regular line of street when taken down, on payment of compensation,[133] and this and the following sections were incorporated in the general Public Health Act 1875.[134] “The commissioners may give notice to the occupier[135] of any house or building to remove or alter any porch, shed, projecting window, step, cellar, cellar-door, or window, sign, sign-post, sign-iron, show-board, window shutter, wall, gate, or fence, or any other obstruction or projection erected or placed after the passing of the special Act, against or in front of any house or building within the limits of the special Act, and which is an obstruction to the safe and convenient passage along any street, and such occupier shall within fourteen days after the service of such notice upon him, remove such obstruction or alter the same in such manner as shall have been directed by the commissioners, and in default thereof shall be liable to a penalty not exceeding forty shillings; and the commissioners in such case may remove such obstruction or projection, and the expense of such removal shall be paid by the occupier so making default, and shall be recoverable as damages; provided always, that except in the case in which such obstructions or projections were made or put up by the occupier, such occupier shall be entitled to deduct the expense of removing the same from the rent payable by him to the owner of the house or building.” The wall of a garden in front of a house, and shrubs in the garden, which encroach on the street, come within the words “any other obstruction” in this section.[136]