I am excited to introduce you to one of my ongoing deep energy retrofit projects we are calling Old House – New Energy (OH-NE). Like a lot of older homes in the Twin Cities, this 120 year old home has an abundance of existing beautiful architectural character and detail, but is at the stage where it is in much need of an energetic upgrade to put it on track for the next 120 years of its life.
In many regards it follows in the footsteps of Net Zero Victorian (NZV) which we upgraded a few years ago. Built in 1904, OH-NE is even slightly older than NZV, but also seeks to apply a conservation-first approach to achieve renewed durability, net-zero annual energy performance and an improved layout to better serve the owners’ contemporary lifestyle. Some additional specific points of emphasis in the process are as follows:
- Preserve and enhance its architectural beauty but also preserve significant embodied energy and embodied carbon through the remodeling process.
- Wrap the exterior walls and roof with continuous insulation.
- Improve indoor comfort and air quality by replacing the old gas-dependent cast iron radiator heating system with a new ducted heating and cooling and fresh air system that utilizes electric ground source heat pump technology.
- Significantly upgrade existing window performance while preserving the art glass and most existing window frames and intricate interior trim, staying true to the original character and detail.
- Convert the basement into usable space while addressing previous foundation water leaks and high radon levels.
- Convert the entire home to all electric.
- Add solar photovoltaics.
I decided not to wait until the very end of the process on this project to write and share about it, but rather bring you along for the ride periodically as the process unfolds.
That said, here are a few photos from before any remodeling began. Despite being in the city it is somewhat hidden by the trees, particularly on the side facing the busy street. We are working around them with the goal of keeping them alive.
The first step in nearly every remodel involves documenting existing conditions. We carefully measured, photographed and modeled the entire house in this case since the remodel will be touching nearly all parts of the house in some way.
We also had an Energy Audit and Whole Home Assessment performed to learn as much about existing conditions as possible to help make informed decisions throughout the design and remodel process. The GreenStar Assessment Form is a great tool for this. It is a little like when you go to the doctor for an annual visit and the first thing they do is check your temperature, breathing, blood pressure, pulse rate, etc. An air leakage test (blower door test) is a big part this.
The overall house leakage came in at 4,154 cfm50. We are hoping to cut that in half by the time we are finished with the project. One surprise found in this process was that the house did have a small on-going gas leak . . .Yikes! That certainly provided some additional motivation to remove gas all together and convert the house to all electric.
A previous “remuddler” removed all the original wood lap siding and replaced it with vinyl siding, which can be seen in this photo to be buckling and failing. Of course, they also cropped off much of the exterior trim in the process, as they often do, which we will replace and restore to its original character. We are excited to be using a new lap siding material that will look like the original siding, but has a whopping 94% recycled content from post-consumer and post-industrial recycle and waste streams!
Here the siding is removed and framing for a new guest bathroom is complete and temporarily wrapped with conventional Tyvek house wrap until Blueskin adhering house wrap can be installed.
Moving inside the home, the basement is showing its potential once the existing mechanical system and piping is removed. Existing stone foundation walls will be insulated on the interior, but with a technique that allows them to continue to dry to the interior as they do now. We will certainly improve exterior grading to direct storm water away from the foundation, but cannot fully waterproof the exterior surface of these existing 20” thick stone foundation walls below grade. Thus we must accept that some moisture will likely continue to migrate through them, drying to the interior, as it has all their life. Existing floor consists of concrete tiles loosely fit together and as you can see are not even a continuous slab! It is no surprise that previous radon levels were high!
Here is a similar basement view and an additional one showing the removal of the concrete floor tiles and discovery of the existing stone footings. Next is the initial install of the dimple sheeting on the interior of the stone foundation to maintain an air space for drying toward the interior.
Here the all new sub-slab plumbing rough-ins are complete along with perimeter stone footings wrapped with drain and dry channeling. The perimeter drain pipe and free draining rock is installed and ready for sub-slab insulation, poly vapor barrier & in-floor heat pipes.
Here is the sub-slab insulation (100% recycled EPS), poly vapor barrier & in-floor heat pipes completed. Also visible is some rigid insulation salvaged from the vinyl siding removal which we re-used for sub-slab perimeter (yellow). Under a slab is often a great place to re-use rigid insulation that is broken, slightly damaged, odd shaped scraps from previous projects, etc. I love finding ways to incorporate material re-use and/or products with high recycled content into projects! This obviously helps keep materials out of the landfill and gives manufacturing companies incentive to create new products from recycled content. It is now ready for the new concrete slab!
Here the new slab is complete and interior energy wall framing is getting started.
Coming up out of the basement, this photo is a nice example of the beautiful but poorly insulated existing art glass which we will be preserving and improving with an additional new insulated sash and storm windows.
An example of the beautiful and ornate window trim we are working to leave in place with our window upgrades.
Here is more of the beautiful original stained glass windows and trim to be preserved with protection installed on existing finished floors to prevent damage during construction.
Here the third level is ready to be transformed into a fun rec room. Old roof structures like this are often structurally stable, but can be complicated and expensive to re-frame to change the shape, given current structural code requirements. Thus we will be using an innovative technique to add insulation and simple reinforcing to avoid much of that complexity and cost, yet significantly improve its energy performance, durability and strength to support new solar panels as well.
Here the attic demo is complete, including removal of original chimney.
That’s all for now! Check back again over the coming weeks and months to see more updates as we continue to give this Old House, New Energy!