For the latest information on tax credits and energy rebates please visit these websites:
www.energystar.govCommercial Tax Credits for multi-family apply to any rental housing – single unit to 100+
The Oregon Business Energy Tax Credit is very significant- 35% of eligible project costs taken over 5 years. If the project cost is less than $20k, the allowable costs can be taken in 1 year.
See Oregon.gov