| Hi gripp2020,
The first aspect to consider in order to design your basement is "what you are allowed to do". Check with your building dept the egress windows, ceiling height, ventilation systems, etc
The second part is a realistic $$$ estimation--> there are many things that you can DIY, however, for permits, seals and inspections you'll need to pay someone to do this for you
As for the layout, keep it simple and consider that you'll improve it in the future. For example, a wet bar. perhaps you can't install this now, but set the plumbing in order to install it in the future
If you can post pictures and dimensions as well as your ideas, perhaps I can sketch something __________________ Good luck with your project!  Patricia |