Exterior Insulation Options
Choosing the exterior insulation of a home is an important step in achieving optimal energy efficiency and sustainability goals. At CSA, we work with our clients to find the best product for their home through suggesting insulation products that align with our values. Products we often recommend to clients who seek more environmentally conscious options include Rockwool and ZIP R Sheathing.
A sweater for your home
Traditional insulation methods typically involve filling the wall cavity between studs with some sort of insulator— spray foam, fiberglass batts, loose fill insulation, etc. These options insulate the space between wall studs, but do little to prevent heat loss at the studs themselves. This is why we ask:
Would you rather eat your coat or wear your coat?
Rockwool and ZIP R Sheathing are both systems that the house “wears” (placement is on the exterior of the wall studs) rather than “eats” (placement is inside the wall cavities). This allows for more consistent thermal protection.
Rockwool
Rockwool is a form of stone wool insulation made by spinning molten rock and minerals with steel slag to form a wool-like product. The material can be pressed into rolls and sheets of various densities with incredibly effective sound-absorbing and fire-resistant properties. Additionally, stone wools are water repellent and resistant to rot, mold, and mildew growth.
Rockwool provides a variety of products with specific thicknesses, R-values (the measure of a material’s thermal resistance with a greater number indicating better insulation), and lengths. Learn more about their product and commitment to sustainable practices on the Rockwool website.
We used Rockwool for the exterior insulation on our Cypress & Bluestone project. In the photos below, you can see the green-brown material covering the house in a wooly blanket.
In addition to being a great insulator and keeping the house energy-efficient, the sound absorbing properties of Rockwool made it a good fit for this project. Located in Linden Hills, Cypress & Bluestone is under a flight path for MSP Airport. Using this material quieted the noise from overhead airplanes inside of the house!
ZIP System R Sheathing
Another product that we recommend to our clients is the ZIP System Insulated R Sheathing. This system is an all-in-one structural panel that offers built-in exterior insulation.
The panels consist of a weather-resistive barrier covering the exterior structure (plywood), with insulation adhered to the interior side. The insulation comes in a variety of thicknesses and R-values and the panel themselves can be ordered in specific sizes for easy assemblage. Adjacent panels are sealed together with a ZIP system tape that forms a continuous water and air seal, reducing leaks for a more energy-efficient exterior.
We used ZIP panels on our GreenHouse ADU project, seen below.
Read more about the advantages of using this system in this publication focusing on GreenHouse.
Exterior insulation can have a big impact on your home’s energy footprint. At CSA we look forward to discussing the advantages of each material and helping you find the best option for your project.
Read more about the featured projects: Cypress & Bluestone and GreenHouse.