In simplistic terms it is the sacrifice of something for something else. So, as to trade off the negative social consequences (building being too high in a local area and the unhappiness of those whose views would be effected negatively) for an economic benefit (increased revenue due to a larger building can have a higher capacity of rooms). In this scenario the trade off is the social unhappiness for the increase in revenue. This however can be used for any three of the pillars of economics (Social, economic and environmental). I'm not sure if this is 100% relevant to you as I am from Australia and not the USA.