Look at the insulation in the attic, look at your soffits to make sure you're getting enough airflow through the roof.

You can easily snag 1% rent to value ratio here, it's a market where the population is growing and we're very insulated to recession! 

The current building code has many green initiatives which require things like energy efficient windows, and insulation in the walls (not common practice 50 years ago when much of was built.Outside of the City and County of Denver it varies significantly and most jurisdictions aren't set up to provide concrete guidance from the start like Denver is. 

Current as-built drawings, plans & specificationsDescriptions of buildings, physical aspects and systemsSite Plan (with dimensions and identifying tenants and vacant locationsPhase I and if applicable Phase II environmental site assessmentProperty Condition ReportStatus of ADA compliance (including ADA plans)Warranties (HVAC, roof, insulated glass, etc.)Existing exterior, interior, and aerial photographs of PropertyFloor plans with tenant location (CADD/PDF files)Any and all Leases and Tenant correspondenceAny and all Service ContractsGeneral Ledger for the past 3 yearsThree year history of delinquency and bad debtMost recent detailed billing statement for all TenantsTenant ledgers for previous calendar year & YTDCertified Updated Rent Roll and Certified A/R ScheduleList of security deposits and prepaid rentLeasing update (pending deals, LOIs, renewals, lease-up projections)Future Tenant improvements and leasing commission obligationsThree year history of tenant improvements and leasing commissionsCurrent year detailed operating budgetYTD budget vs. actual analysis for current year & 2 prior yearsThree years of operating statements (revenues & expense) historyCapital items/budget forecast (3-year projection)Three year history of capital expendituresProperty Tax bill for current year and previous 3 yearsCurrent Insurance CoverageThree year history of insurance claims and incidentsTenant’s sales volumes for at least 3 yearsThree year occupancy historyExisting appraisal report(s)Confirmation of ZoningCertificate of occupancy/use permitsStatus of pending litigation and/or threatened condemnationMost recent title insurance policyMost recent as-built surveyCAM Reconciliation for prior 3 years

Austin is also very government based so it becomes more insulated to the ebb and flows of the economy at large.

I think the main differences would be lower prices in OKC and more insulation to recession .. all depending on where you're looking in Texas of course.

I thought about a thin layer of spray foam insulation, but am not sure.

They have old pier and beam foundations which will need to be leveled, they will need new wiring, new plumbing, probably new siding with insulation.

Storage containers usually stand superior in the face of building codes.Properly insulated, they can make for a warm and cozy home in the winter.

If you go this route, pull all your wiring and plumbing before insulating.