MISSION
with practical, cost-effective solutions driven by building science.
Air Sealing, Blower Door Testing, Duct Testing, and Plan Analysis
Save money while meeting the Energy Code with our D.R. Nelson Energy Seal ServiceĀ®.
Heat Calcs & HVAC Design
Design an energy efficient HVAC system with our Manual J, Manual S, and Manual D calculations.
Enclosure Integrity Testing on Fire Suppression Systems
Deliver a successful new fire suppression system to your client with our Enclosure Integrity Test and Room Sealing.
"I first met Don Nelson, President of D.R. Nelson & Associates, in 1982. At that time, we asked him to help us do a better job of insulating our houses. What impressed me was he solved our problem by thinking outside the box, and he has been that way with every problem we ever asked him to solve regarding energy efficiency. I think he is a terrific individual and very talented. He's the best!"