Bark of a tree is like the façade of the building. The outer layers prevent most elements and other things to penetrate into the inner layers of the organism.
The stomata of the leaves of any plant is similar to the HVAC system. It controls the inflow and outflow of gas to the organism so that it can maintain the proper oxygen levels and heat levels. It can control the heat levels indirectly by releasing vapour through evapotranspiration. By that analogy, I guess it's also similar to a plumbing system in some ways. Leaves are also the original solar panels!
Capillary action in the veins of the trees act as the corridors and transport system of the 'building'. It ensures that materials can be delivered and people can move from one place to another within the building.
The root system acts as the foundation and ensures that the plant is able to stay upright despite growing in size. A building also needs a stable foundation to operate properly.
The ability for plants to adapt to any situation can kind of be thought of as the resilience factor of a building. It should be able to adapt to a variety of situations.