I really love the idea of creating a setting and environment that includes both able and disable people. It's truly inspiring and interesting to think about.
As someone who has not spent any time before thinking about the requirements that such things might need, I don't necessarily have many thoughts on what the final product might look like. I do however think about identifying requirements as part of my professional life daily. I think that it might be very helpful to list as many of the specific requirements, both functional and elective, that bear on the outcome for the final design.
Some additional design questions that might be helpful to know the answers to: Is this meant to be deployed in a single location in Ghana only, or in multiple locations? Given the way that the local environment breaks down most materials, what is the desired longevity of the final product? 1yr, 3yrs, etc.? Does the material choice need to be an abundant local material or can it be sourced globally? What are the budgetary constraints for a completed product? What level of production is expected to be achieved for the final product? Meaning, will we always build it manually onsite, or is it ever expected to achieve some or any economies of scale? What are the safety parameters for the product? What level of ability is the user expected to have on their own to be able to use the device? Should they be able to access/use it without assistance, or is it expected that they will have a caregiver help them to get set up and use the product? Given weather, environment and insects as common issues for product longevity, can these be addressed separately? Can we find materials that have inherent anti-bacterial/microbial properties? Are there ways to mitigate weather conditions that blend with the environment and are also functional and aesthetically pleasing?
I offer these additional questions and hope they might be useful in taking the design process in useful directions.