First of all: it depends on the relationship between resources. Is it with the contractor, the design unit or something else?
Second: You need to see which one is more profitable and easier to cut in. It's all about relationships these days. Try not to touch other people's cakes. Otherwise there will be trouble.
Third: If it doesn't matter, find the corresponding suppliers, such as steel, cement, bricks, wood, glass, decoration materials, elevators and hydropower materials. These things are indispensable for buildings such as houses and factories, and several projects come down every year. Quite a few. :)
Fourth: if we can operate behind the scenes, such as building projects can help contractors win, the profits will be even greater.
Send me a message if you have any questions. I have some such resources here.
Fifth: you can take some low-priced houses or shops, wait for appreciation and collect money.
We can discuss it together. :)