Your first question:
to understand better, think of it this way;
The DDO First acts as a REIT which plans; in advance; feasible project proposals based on Yield and Profitability potential of each proposed project. These Proposed Projects come in bundles (1 proposed project = 1 land + 2 proposals (2 project possibilities on the same land)). After that, and on behalf of the Token Holders, the DDO acts as a Developer which buys raw land, obtains the necessary permits, puts in the sewers, water and electric lines and put together (Build) the prefabricated structures using our own engineers and workers. after that we hire subcontractors for heating/cooling and plumbing services.
We basically combine the property Development AND Real Estate Investment management business model with the technologies of High Rise Prefabricated buildings and the advantages it offers in duration and cost reduction = Rental Yield increase. BSB is a company, like many in Mainland China offering prefabricated building structures with international technology franchising rights.
Our team's expertise in Real Estate Development as well as Real Estate Management is extensive and plan to capitalize on all of the above.
which brings me to your second observation;
The reduction is from 25%-40% of the total construction cost because prefabricated structures need less man power and machinery, which is always the highest cost of construction. this reduction of cost is widely know in the prefabricated building industry and you can just search it up. not mentioning numerous other operational, constructional and financial benefits. this technology (when applied to high rise properties like towers, etc) have existed for 2 decades now. and prefabricated building concept has come a long way since the first ever prefabricated house was sold in late 1880's.
this technology is foundational to the 30%-40% Annual Rental Yield produced by all Block Estate DDO Properties. and is exclusive to BDDO because once the properties are sold on their market price, the 30%-40% Rental Yield disappears and becomes the Average of 5% produced by most properties. meaning the longer the Payback Period is, the higher the property retention rate, therefor higher total property value will allow for systematic increases in Rental amount, exponentially increasing the Rental Yield.
and no it will not take 12 months. in fact, one of the foundational projects is a 16 floor Condominium which will be will be finished in 6 months (and this is the furthest stretch).
in prefabricated buildings, preparing the structure (16 floors) takes 2-4 months. and erecting the structure on the Land takes an unbelievable 2-6 weeks only!
and no, the owner is not all that happy. because the owners of the properties are actually the Token Holders with the organization acting on their behalf. therefor the Token Holders are happy . meaning 100% of profit produced from such high yield per property (after management and property maintenance fees, etc) goes to a DECENTRALIZED ACCOUNT which is placed on the Blockchain. (remember how high the yield is).
and by utilizing this Dec Acc, Token Holder SOLELY have the power, through a smart contract managed voting system, to steer the target project of the organization by controling the entire profit of the organization (only projects voted for by majority receive funding from decentralized account)
you can check this link for more information: https://bitcointalksearch.org/topic/m.38701536
also, on the above link i posted some images in the 1st and 2nd post. you can only click on them to veiw them because i am still not a junior member. the business model is clearly outlined there, and for the sake of time i will post it here too: https://imgur.com/a/NGyybPi
THE 30% AVERAGE ANNUAL RENTAL YIELD IS NOT BASED OF ANY TOKEN OR COIN, IT IS BASED FROM REAL CASH RENT RECEIVED FROM RENTERS BY BLOCK ESTATE DDO. it is not only sustainable. it will actually increase even more during the Real Estate Market expansion (bull) cycles due to increase in the total underlying market price for the Property if purchased Ready Built.