This section is from the book "The Principles And Practice Of Modern House-Construction", by G. Lister Sutcliffe. Also available from Amazon: How Your House Works: A Visual Guide to Understanding & Maintaining Your Home.
Fig. 724 shows the distribution of light and shade, without regard to the angle of aperture, in the ground, first, and second stories of houses, the heights of which are to the width of the streets as 1:1, 1: 1*5, and 1:2 respectively. It shows also the improvement of the illumination of the lower rooms with the widening of the street.
Town-Houses. - The light and air of cellars and basement-rooms must not be forgotten. If the entire site of the house be laid with concrete or asphalt, and the walls and footings to the ground-level protected from damp, one great objection to underground rooms is removed; hut when such are occupied continuously - whether as living rooms, kitchens, offices, workshops, warehouses where packing is carried on, or indeed otherwise than as mere cellars for coal, beer, or wine, - they should be brought under the same regulations respecting light and air as over-ground floors; and the diagonal, whether at 45°, or as at present permitted in the Metropolis at 63.5, with the ground, should be drawn to the sills of the basement windows, and not of those of the ground-floor. This would necessitate the excavation of wide areas in the rear, and would preclude the practice of building a roof over the yard, which is often allowed, though it converts the ground-floors into back-to-back buildings, and consequently adds considerably to the difficulty of ventilation. The requirements of the London Public Health Act, 1891, Sec. 96, are a considerable improvement on those of the corresponding Sections 72 and 74 of the Public Health Act, 1875, in force elsewhere, though they are to a great extent nullified by the exemption of underground rooms which are occupied together with any other apartments in the house.
Again, all regulations as to the number of square feet to be left vacant in the rear of a building are futile, unless the free movement of air along the entire length of the block is ensured; the so-called open space in the rear of some aristocratic "mansions" or block-buildings is really nothing but a well. For like reasons, squares, quadrangles, and courtyards, surrounded by buildings on all sides, should have openings - not necessarily thoroughfares - at the corners to permit free circulation of the air.
Fig. 724 -Influence of Width of Street on Illumination of Rooms.
Streets cannot be too wide, and should never be less in width than the height of the abutting buildings, to which again a limit should be placed; the height of 90 feet to the wall-plate or eaves permitted by the Metropolitan by-laws is certainly too high, except for isolated buildings standing in extensive grounds, or for factories and warehouses. Fig. 725 shows the requirements of the regulations adopted for new buildings in the residential streets of Liverpool, and recommended in the Metropolitan Bill as originally drafted. The height of the houses, it will be seen, is not to exceed the width of the street, nor in any case to be above 90 feet from the ground to the top of the walls; while a line drawn from the ridge of the roof to the foot of the wall of the opposite houses, or in the rear to that of the wall or fence dividing the backyards of contiguous houses, is to make an angle of no more than 45° with the ground, which is, in fact, that obtainable in a street where the height of the walls does not exceed its width, and the pitch of the roofs is not more than 45°.
Fig. 725. - Diagram illustrating Regulations for New Houses in Liverpool.
The paving of streets has an important effect on the health and comfort of householders in towns. A perfect paving should present a surface sufficiently hard and smooth to reduce the friction of passing vehicles to a minimum, while at the same time affording the requisite foothold for horses; it should be durable, not wearing into furrows and depressions, or crumbling into dust; impervious to moisture, easily cleansed, and sufficiently elastic to be nearly noiseless. Such an ideal has not been, perhaps never will be obtained, but the nearest approach is likely to be found among the asphalts or concretes, the chief defect of which is their "greasiness" when neither quite dry nor thoroughly wet Granite cubes are durable, but the noise of traffic over them is intolerable in residential quarters. Wood paving when first laid seems perfect, but it is not lasting and, in spite of treatment, is too absorbent, often emitting in hot weather a perceptibly immoniacal odour. Macadam, though suitable for country roads and quiet suburban streets, is wholly unlit for the lines of heavy and ceaseless traffic. The practice of repairing such roads with gravel and flint is bad, since crushed Hint has no tendency to consolidate; tot country roads at any rate, limestone is even better than granite, becoming compressed under the traffic into a mass almost resembling concrete. The more frequently and thoroughly a macadamized road is swept, the less the wear and tear and the total quantity of detritus removed in a given time.
For foot-ways the Imperial. Victoria, and other artificial stones are good materials, now being largely used in preference to York flags, which, as is implied in their name of flag-stones, are given to flaking, especially after frost. Asphalt and concrete laid in situ are, in some respects, excellent materials for foot-ways; they are practically joint less, and therefore present an even surface easily cleaned, and from which rain rapidly runs off. This very continuity of material has. more especially in the case of concrete counterbalancing disadvantage, namely, the difficulty and expense of taking up the pavement when required for laying or repairing the mains for water, and electricity, and the still greater difficulty and expense of making the pavement perfect again.