The type of adaptive reuse project you are describing might take months or years to plan depending on how busy your engineers, planners, zoning attorneys,  and general contractors are in your market.

I'm a tax and financial planner that specializes in real estate! 

My brother has contacted a designed planner and received a quote for $35K that covers the planner's fees, property layouts, and some permits.

There are recent posts on this issue, listing questions to ask accountants as you vet them, as well as the differences between a tax-planner and a simple tax-preparer. 

Once you confirm this I would then proceed to talk to a civil planner/engineer and the local utilities company. 

Meaning, that you have to email your planner and any other department head that is working on your project bc they are human and they will forget or miss deadlines. 

Can anybody here connect me to a building planner in massachusetts?

I'm bringing the team: architects, designers, planners, builders, investors, lenders, etc.

Some of the broad questions I would ask a potential CPAs may include 1) their experience with rental real estate as a whole, 2) are they a tax-planner or just a tax preparer - huge difference, 3) how often they will update your books (monthly, quarterly, or at the end of the year), 4) their strategies for depreciation, 5) how they would handle deductions/depreciation on a rental unit re-hab, 6) their recommendations for cost-segregations, and 7) how they approach the addition of more rental properties.

If I never buy another house I am in a great position so I might as well enjoy it a bit now for no one knows what tomorrow holds.I encourage you to talk to a financial/wealth planner.