My wife and I tried out a lot of innovative systems and materials in the renovation/rebuild of our Dummerston, Vermont home — some of which added considerably to the project cost. Alas!
The induction cooktop that I wrote about last week is just one such example.
For me, the house has been a one-time opportunity to gain experience with state-of-the-art products and technologies, some of which are very new to the building industry (like cork insulation, which was expensive both to buy and to install). We spent a lot experimenting with new materials, construction details, and building systems. While we haven’t tallied up all the costs, we think that the house came in at about $250 per square foot.
All this has raised the very reasonable question about whether all this green-building stuff is only feasible for high-budget projects.
So I’ve been thinking about what lessons from our project would be applicable to more budget-conscious retrofits. Here are some thoughts.
Keep it compact. In renovating the old farmhouse we shrank the footprint, eliminating a kitchen addition that had been added perhaps in the 1920s. Fitting the kitchen into the main house meant some tricky design work, but it helped us contain costs with the exterior envelope and finishes. This cost-saving strategy applies whether with new construction or renovating an existing house. The cost per square foot will likely go up with a smaller house, but the total cost should drop — and there will be less volume to heat and cool.
Deep-energy retrofit with mineral wool. The cork insulation we used as an insulation wrap on the walls was really amazing, and I’m glad we used it, but if we were doing the project over with a more constrained budget, I think I would have gone with rigid mineral wool. Carrying out a deep-energy retrofit by wrapping a house in rigid insulation is never inexpensive and it depends on having deep enough roof overhangs, but with rigid mineral wool (such as Roxul ComfortBoard or the highest-density Thermafiber product) it can be a much more reasonable retrofit.
High-performance storm windows. While our low-emissivity (low-e) storm windows on the south and east facades aren’t installed yet, they can provide a reasonably priced alternative to window replacement with top-performing, triple-glazed windows. The idea is to keep the existing (prime) windows when installing exterior rigid insulation on a house and add window surrounds to extend the window openings to the new outer face of the walls — and then install the storm windows near the outer face of the window surrounds.
Air-source heat pump. The heating system we went with on our house is a great option today for compact, very well insulated homes, while larger, ducted versions of these systems will increasingly make sense for replacing conventional gas or oil heating systems. On a cost per million BTUs of delivered heat basis, air-source heat pumps are significantly less expensive than propane and heating oil, and they can be pretty competitive with natural gas — especially if natural gas prices keep climbing. An air-source heat pump means electric heat, but that opens the door to generating the electricity you need — now or down-the-road — with a photovoltaic system.
Water-efficient products. We went with state-of-the-art water-conserving plumbing fixtures and appliances. The 1.75 gallon-per-minute Kohler WaterSense showerheads in our two bathrooms significantly reduce hot water use, compared with standard 2.5 gpm models, saving energy as well as water. And they don’t cost any more than standard models.
Rainscreen detail on exterior walls. We spent a little more installing strapping over the exterior sheathing so that the siding will have an air space behind it, but the cost is low enough and the durability benefits great enough that this should be standard practice today. We will save thousands of dollars over the years by having to paint the siding only every 15-20 years (I predict), instead of as often as every five years, and a big part of the difference is the rainscreen detail.
Salvaged materials. We were able to save some money — and with more concerted effort, could have saved a lot more — by making use of salvaged materials. We bought a salvaged newel post and balustrades for the stairs, for example, picked up a discontinued floor-demo front door, purchased salvaged timbers for post replacements in the barn, and bought superb two garage doors from the now (sadly) closed ReNew Salvage in Brattleboro. Using salvaged materials not only saves money, but it can also help the environment by allowing us to save in raw materials extraction and by reducing pressure on landfills.
Saving resources, saving energy, and saving money when building
These are just a few examples of how a green, energy-efficiency agenda can be achieved with an eye towards economy. Building or renovating with a goal of energy savings and environmental stewardship does not have to have a huge cost impact.
Fundamentally, it’s all about savings — saving energy resources and saving the environment. If we were to put an economic value on protecting the environment, those environmental savings with our house might have compensated for the increased cost of building. But we’re not there yet.
Alex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. In 2012 he founded the Resilient Design Institute. To keep up with Alex’s latest articles and musings, you can sign up for his Twitter feed.