First of all, mushroom-specific growth substrate should be selected. Nitrogen concentration is very important, although some mushrooms don't like high concentration of nitrogen. In some mushrooms size and weight of fruiting body depends on the size of bag.
In addition, each type of fungi require different environmental conditions (light, CO2, oxygen, etc.). Spores of one species can be detrimental to others.
Indeed, Pleurotus spp. cultivation is easy. You can use any agricultural residue. I suggest increased spawn dose to compete with other microorganisms, to accelerate the substrate colonization, and to increase mushroom yield. Control of CO2 concentration is very important to form right fruiting bodies.
I think that the book: Mushroom Growers´ Handbook 1: Oyster Mushroom Cultivation, ISSN 1739-1377, Edited by MushWorld (non-profit organization), Published by MushWorld – Heineart Inc., Seoul, Korea. 298 pp. 2004.
Can be useful for you. I believe it can be free download in:
Dear Building a mushroom house depend upon your space /land as well as your investment, then accordingly can design your farm. What ever material in your place, according your material build a farm?
Mushroom size depends on your financial potential. However, all required conditions (clean air, humidity, temperature, light) should be provided. BE mainly depends on the mushroom strain peculiarities and growth substrate. You should screen and select the best substrate among locally available lignocellulosic materials.
I prefer bags, the yield is higher in a shorter time.