This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol5", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
The first question to decide in the planning of this portion of the crematorium is the number of furnaces to be installed, and whether it is proposed to form it as an open chamber or with an intermediate or receiving room. It will be found quite sufficient if the portion of the chamber occupied by the carriage, while waiting to receive the coffin, is enclosed with black drapery to obstruct any light and view of the cremating chamber, and the increased cost of the receiving-room will be saved.
The following are the dimensions of the principal crematoria incinerating chambers in England Golders Green, 62 feet long by 40 feet wide (four furnaces); Leicester, 43 by 24 feet (two furnaces); Birmingham 38 feet 6 inches by 25 feet, including intermediate chamber (two furnaces); Sheffield 36 by 36 feet (one furnace); Hull, 20 by 24 feet (one furnace); Ilford, 30 by 37 feet (two furnaces). When planned for a single furnace this chamber should have a minimum width of 20 and 25 feet in length, which will be sufficiently large for any furnace at present in use. In considering the design of this apartment it must be remembered that the front of the furnace should, in every case, stand 10 feet from the wall of the chapel, this being necessary for transporting the coffin from the catafalque. When one of Messrs. Simons' furnaces is installed a basement is required 6 feet 6 inches in height, to receive the lower portion of the furnace, and for the purpose of stoking and commencing the fire. With this furnace it is advisable to construct the floor over the lower chamber with a clear space around the incinerator, so that any expansion or contraction which takes place will in no way affect the structures.