Managing an IT project and building construction project has their own obstacles and scales of efforts. As an IT project is mainly in soft form(no physical) which you can rollback and create again and again according to the customer requirements. But on the other hand a building construction is more like one time shot, you can not request customer to give one more chnce to rebuild that building.
on the other hand IT projects need more mind numbing decisions and actions to takes, such as thinking of new logics and idea on each part of a software, whereas a building constuction needs a predefined blue print created according to customer.
so there are no comparison scale but still i will say IT projects are not as easy to manage as it takes alot of constant changes and decisions.