“And they may further provide for the observance of such byelaws by enacting therein such provisions as they think necessary as to the giving of notices; as to the deposit of plans and sections by persons intending to lay out streets or to construct buildings; as to inspection by the urban authority, and as to the power of such authority (subject to the provisions of this Act) to remove, alter, or pull down any work begun or done in contravention of such byelaws. Provided that no byelaw made under this section shall affect any building erected in any place (which at the time of the passing of this Act is included in an urban sanitary district) before the Local Government Acts came into force in such place, or any building erected in any place (which at the time of the passing of this Act is not included in an urban sanitary district) before such place becomes constituted or included in an urban district, or by virtue of any order of the Local Government Board subject to this enactment. “The provisions of this section, and of the two last preceding sections, shall not apply to buildings belonging to any railway company, and used for the purposes of such railway under any Act of Parliament” (38 & 39 Vic. c. 55, s. 157). The result of this power having been so given to urban authorities, is that they have all framed sets of byelaws, which having received the sanction of the Local Government Board, are now law in the several districts. In the year 1877, it being found that considerable variation existed in the requirements set forth in the byelaws, according to the districts from which they emanated, and experience having shown that the forms of byelaws previously issued by the Local Government Board were inadequate, the Local Government Board in order to assist urban authorities issued a series of model byelaws; amongst the series being a set of byelaws regulating the manner in which new streets should be constructed and buildings erected.[153] These model byelaws are too extensive to give in detail, as they contain 99 clauses, but every town surveyor should at once procure a copy, even if his corporation have not adopted them, nor intend to do so. One of the first difficulties that often presents itself to those who have to enforce the observance of the necessary “giving of notices and deposit of plans and sections by persons intending to construct new buildings” is to prove that the building is “new” so as to bring it under the operations of the Act. In many cases, of course, there can be no doubt where bare land is being built upon, but often after buildings have been partially destroyed by fire, or where extensive alterations are being carried out, some considerable elements of uncertainty as to what is a “new building” are introduced. The law attempts to settle the question as follows: