I like a couple things in this abstract from the journal Cities.

One is a definition of hybrid infrastructure as “infrastructure systems that are integrated within buildings and landscapes that also provide non-infrastructure uses”. In other words, you are trying to kill two birds with one stone. This should be efficient and cost-effective compared to killing two birds with two stones, but the reason it often doesn’t happen (at least in the U.S. cities I am familiar with) is that there are typically two entities responsible for killing one bird each, and if their stone happens to kill the other bird they will ignore that and not count it as a benefit. Each agency calculates the cost as one stone, while the actual cost to society was two stones. (The only problem with this analogy, obviously, is that we are talking about ecological benefits and killing birds would actually be bad.)

The second thing I like is that the question asked is about the “maximum ecological performance potential of buildings and landscapes”. This is a nice question to ask – not just how can one type of infrastructure perform one function cost-effectively, but how can it fit into the landscape and perform many functions at the same time. If those two agencies (or in real life, 10 or 20 agencies) were all asking this question together, maybe you could achieve much better outcomes in cities.