Seeking Your Insights: Energy Efficiency & ROI in Historic Duplex Renovation

[Daniel M.]

Hello BiggerPockets Community,

I'm embarking on an exciting journey to acquire and renovate a duplex from 1900, aiming to tackle the inherent challenges of outdated insulation and the lack of modern vapor and air barriers. To kickstart this project, a comprehensive home energy audit is on my agenda to craft a strategic retrofit plan that significantly enhances operational efficiency by 40-70%.

This endeavor seeks to diverge from common quick fixes, such as installing baseboard heaters, which merely shift heating costs to tenants. My vision is broader: I'm investing in high-quality renovations to offer more comfortable, healthy, and affordable living spaces. By potentially halving heating costs for tenants, I anticipate fostering more extended tenancy periods, thus reducing turnover rates and driving up ROI.

Drawing upon the expertise of renowned professionals like Michael Maines, Emily Mottram, Joe Lstiburek, and Allison A. Bailes, I've delved deep into the complexities of vapor dynamics and the importance of tailoring retrofit strategies to the specific needs of older buildings. Their insights highlight the necessity for a careful approach to vapor barriers and insulation, emphasizing compatibility with the building's original design and moisture management needs.

Here's the plan:

• Ceilings/Attic Floors: Elevate insulation to R-38 or above, incorporating vapor retarder paint or smart vapor retarders for optimal moisture management.
• Walls: Boost insulation to R-13 or more, utilizing smart vapor retarders or materials with adjustable permeability.
• Basements, Crawl Spaces: Increase insulation to R-19, targeting ground moisture and internal humidity control.
• Materials: Opt for eco-friendly, breathable insulation and vapor barrier materials that preserve the building's historic charm.

This meticulous approach elevates the property's energy efficiency and moisture management, enhancing its value and ensuring a profitable return without compromising its architectural integrity.

I'd like to hear your thoughts, experiences, or any advice you might have on integrating vapor barriers and insulation in renovating historic properties. Have you undertaken a similar project? What challenges did you face, and how did you overcome them? Your collective wisdom will be invaluable in ensuring this project not only preserves the building's heritage but also meets modern performance standards, increasing its market appeal and overall value.

Let's discuss it! Please share your insights, questions, or stories in the comments below. Your feedback is welcome; it's essential to making this project successful.

Thank you for engaging in this discussion. I look forward to your valuable input.

[Joel Forsythe]

1st off- Kudos for your enthusiasm to tackle a difficult problem; adopting new materials and building science understanding on really old structures.

Success levels for energy retrofitting will be directly tied to the level of "gutting" you do to the old house, especially trying to add a vapor design and passive ventilation retrofit. You really need to separate that scope from thermal insulation. If your pulling every mechanical component out, most interior wall and ceiling cladding, then the ROI on the energy upgrade may spec out nicely over a period of yearly savings (many years). Most of the time, however, too much cladding or systems are left in place, making (serious) vapor barrier improvements infeasible, let alone solving passive ventilation needs created. You simply can't effectively work around a spider nest of wiring, piping, ducting, with cramped space to really address vapor installation plus new passive ventilation modification.

So, most just jam more insulation in, upgrade better performing windows and doors, and call it a day.