The Darwin Pigeon loft was built by local Downe Carpenter John Lewis. It was based on designs maybe seen in pigeon books of the time,It was hexagonal with a high pitched roof, light coming from openings in the pitch, otherwise known as a lantern, having no windows other than a pop-hole opening into the aviary.
I would have thought this too dark ,perhaps there was a wire door fitted at the entrance door to let in further light and fresh air, if not it would soon become unpleasant for both Darwin and the pigeons. Breeding cages arranged all around the walls were 4 high and being 3 foot long, 18 inches high, 20 inches deep.
In the loft used for the film "Creation" the cages all had dowelling fronts but maybe only two rows would have been like this, the rest more open, bearing in mind large birds such as English Pouters, Scandaroons and Runts would not be able to access this type of cage. The dowel fronted cages would offer the smaller breeds such as Tumblers and Rollers a degree of safety while rearing young. On the front of the loft was a large aviary, 9 foot high, where the pigeons could be exercised or their habits studied by Darwin such as the mating ritual, bathing and sunbathing.
I have included other Victorian loft designs on this page just to give an idea of different styles bearing in mind fanciers would have varied from the well to do to the ordinary working chap in a small house or attic bedroom.
Larger octagonal flint and brick built dovecotes can be seen at Baliffscourt, Clipping, West Sussex New Timber Place, Hassocks, West Sussex.and West Dean Village East Sussex click to view Pictures