# Maximum building volume optimization with galapagos

Hello!

I am a fairly new user of Galapagos and I’m having minor difficulties formulating a solution within Galapagos that is solvable within a reasonable amount of time. In essence, I’m trying to find the maximum building volume above the pink area on the ground (see image), which can shade the red existing important facades, but only to the degree that these facades still receive a minimum of 1 hour of sunlight on the 21 of December. This is not a regular solar envelope as it is not strictly linked to the ground - it can float in some areas, depending on the optimization.

The fitness is currently composed of 2 variables. One is the value of received sunlight (calculated with Ladybug for each individual building) and the other is the total gained volume, both weighed at 50% and trying to be maximized. Geometry is the bigger problem; I am not sure what is the optimal and simplest way to formulate the “search for geometry” so that Galapagos can be effective? One idea I have is making a 3d array of cubes acting as pixels for him to turn on or off, but the issue here is that we soon run into hundreds if not thousands, each needing its own gene. What would be your suggestion?

Some other questions:

• Is this problem realistically solvable in Galapagos or is it very likely to get stuck in a local maximum and be ineffective?
• Would it be better to include only the sunlight criteria in the fitness and somehow restrict the minimum geometry volume within the parameters?

I hope I was clear in my explanation and thank you very much for all your help!