There’s a myth circulating that super energy-efficient homes cost more to build than homes with typical code-level energy features. Last year, Architect, Richard Pedranti, busted that myth by designing a home to Passive House standards for only $165 per square foot. “We typically use between $175 and $200 per square foot for standard new home construction costs in our area,” said Pedranti.
For that modest price, this Passive House offers three significant benefits: personal health and comfort, superior energy efficiency, and affordability.
The 2,153 square-foot home achieved this with a simple design, lots of insulation, super air sealing and modest package of mechanical equipment. The result attracted quite a lot of attention, including the 2017 Passive House of the Year award and several magazine articles.
The Scranton Passive House is the 112th Passive House certified by the Passive House Institute, US. Pedranti produced a free e-book (PDF) packed with photos, detailed drawings, and useful information on this extraordinary home.
The Passive House program has had immeasurable impact on the North American housing industry by raising the bar for energy efficiency. The organization has set a very high standard of energy performance, trained thousands of professionals, stimulated a growing market for high performance building materials and equipment. Pedranti has managed to meet these high Passive House standards with a home that is cost comparable to similar standard homes in the area.
Simple Design
As with most Passive House designs, simplicity is key. The building envelope is a two-story rectangle. The first floor has an open kitchen, dining, and living space along with a mudroom, office, powder room, laundry room, and mechanical room. The second floor has 3 bedrooms, 2 baths, and a den. A generous front porch on the north side of the home connects to a large screened porch on the northwest corner. These outdoor spaces add a bit of architectural interest and gracious living without complicating the insulation or air sealing details. An arbor across the south side provides summer shading and a porch overlooking the neighborhood. Because the roof of the main house was shaded, the garden shed to the northwest of the screened porch will accommodate solar panels to produce enough on-site energy to achieve zero energy status when the owners are ready.
“I knew when I got into Passive House, there was a hard learning curve, which has everything to do with the fact that you measure things. That’s not the case with a typical, prescriptive code-built home,” said Pedranti. “With Passive House, you create an energy model with a spreadsheet. It’s very detailed. Every bit of material, the design, the orientation of the windows—all that stuff is either ‘yes’ or ‘no’ in terms of meeting the requirements. For me, it’s well worth the extra effort because we make better buildings that are healthier, more comfortable and cost less to operate”
Performance
In typical homes space heating and cooling are the biggest categories of energy use, followed closely by water heating. Today’s super energy efficient homes turn this relationship upside down. The energy breakdown for the Scranton Passive House shows that a whopping 67% of the energy is used for the lights, appliances and other devices that draw power from wall outlets, collectively known as “plug loads.”
All that efficiency adds up to significant dollar savings. If this home had been built to code, it would have cost $233 per month for energy. Instead, the monthly bill has averaged $67. With $166 per month in additional buying power, the owners could qualify for a mortgage that is about $32,000 larger. While it’s impossible to say how much the same house would have cost without the Passive House features, these savings go a long way to funding the energy saving features.
Energy Efficient Features
To achieve these savings, Pedranti designed raised heel roof trusses that allow R-85 ceiling insulation that extends all the way to the exterior walls. Walls are framed with I-joist studs providing enough depth for R-61 insulation. Many Passive House projects use up to 12 inches of expanded polystyrene (EPS) below a slab-on-grade. Instead, this project uses perlite, a natural mineral with insulating qualities. “It has an R-value of 3.5, is environmentally safe, and it is made in nearby Bethlehem, Pennsylvania,” said Pedranti. “It comes in 8-inch bags. Our slab went from R-40 to R-75 at very little cost. I never realized it could be that easy.”
Window area and placement was carefully designed to balance heat loss and heat gain. Most of the windows were placed on the south side to maximize heat gain in winter and reduce overheating in summer. Super-efficient R-7 Eforte windows were purchased from Intus.
While thick insulation increased the cost for the thermal envelope, the entire mechanical system cost only $5,000. This included the 9,000 btu mini-split heat pump, heat pump water heater and energy recovery ventilator. This illustrates how high-performance homes shift cost from large mechanical devices that require large amounts of energy to use to structural features that reduce energy use.
“This was my first super energy-efficient project. It was a very positive and exciting direction in which to take my business,” he said. “I have found over the years that a lot of the bad things in our industry are the result of an overemphasis on pure aesthetics. I really like that Passive House is based on science.”
Richard Pedranti Architect (RPA) is a full-service architectural firm serving the Upper Delaware River Region, as well as Philadelphia and New York. RPA specializes in Passive House and high-performance buildings putting modern building science to work creating beautiful, healthy, comfortable, and energy-efficient buildings.
Anders Lewendal says:
Nice project. While I support the idea of zero energy and Passive homes I am not convinced the costs can equal code built homes of the same design using the same costs of labor.
Can you please help us understand by supplying the final cost analysis of this home? For example: the cost of i joists for studs is much higher than 2×6 studs, high performance window are far more expensive than U .29 good quality vinyl windows. R 60 walls must cost more than code R19 walls. Plus HRV’s are not even required by code.
As builders we need much more detailed information.
Thank you.
Roberto Muller says:
I agree with Anders. I am working on community education about building energy efficiency and everyone I talk to asks about comparative costs b/w Code and Passive House. It would help to have granular details about the costs of Richard Pedranti’s project, besides just saying that rectangular design and an affordable HVAC system brought the cots down.
You wrote, “While it’s impossible to say how much the same house would have cost without the Passive House features, these savings go a long way to funding the energy saving features.” In our efforts to educate our community, it would help immensely to have a cost comparison that shows where the savings happen and where the costs increase with a Passive vs Code house (if both were built with the same “simple design”).
Any chance we could get a follow-up article to answer these questions?
Thanks for raising awareness on this so far!
L A says:
As well – I love the concept but to bust the high cost myth is ??????.
The $166.00 (based on what interest rate??) additional buying power is good but can the buyer qualify for the $32000.00 higher sale price of the home??
This type of home I have experienced easily cost $32000.00 more to build than a minimal code built home.
I know the evolving energy code is helping close the gap on the price issues but on the other hand it is hurting the affordability of a new home. Catch 22??
Question: Do we need to go so hog wild to save so little energy? If we do then let it be known.
Example:
Please supply me with the energy cost saving of the home or a home that has ceiling insulation of R-38 verses R-60.
Please show me the cost difference for the ( M & L) insulation in the ceiling for R-38 verses R-60. The price difference of insulation not including raised heel trusses.
I am proud of the fact it cost (reasonably) more and it should be so noted. Better (sustainable) is always going to cost more.
Bruce Sullivan says:
I don’t have to tell building professionals that cost comparisons are very difficult. There are regional differences, labor shortages, material tariffs, general inflation and other external factors that affect cost. There are also many choices that designers, builders, and clients make for features and materials. The first group of factors is beyond our control, while the second are all choices that we make.
No one can say that an R-40 wall can be built for the same price as an R-21 wall. So any cost comparison that breaks down by component would be missing the point. Many of the specific requirements for zero energy homes will cost more, but that doesn’t mean the house is not affordable.
There are three main ideas that make zero energy homes and Passive House projects more affordable.
Buying Power
The owners save $166 which gives them “buying power” to finance $32,000 more. Will lenders give them that money? In the past, this was a problem, but that is rapidly changing. The Home Style program recognizes energy savings when qualifying borrowers. New lending guidelines from Fannie Mae and Freddie Mac have just been announced that will extend this idea to mortgage originators. There is still much work to do, but those of us in the building industry must press lenders for them to acknowledge this.
Smaller Mechanical Systems
One element of energy efficient homes does save money. It’s the HVAC system. Smaller equipment costs less. Most Passive Houses don’t have any heating equipment. Some of those savings are used for improved ventilation, which many homes need anyway, but just don’t have.
Amenities
Clients, with the guidance and support of professional, can make many choices to reduce the overall cost of the home that will more than compensate for the additional cost of energy savings measures. Do we need commercial ranges, spa tubs, expensive countertops, and other creature comforts? Not everyone does. Richard’s clients were willing to put more money into performance than finishes. Countertops, appliances, and many other elements of a building will need to be changed over time. Wall insulation, air sealing and other performance measures cannot be changed. We need to focus on the substance of our buildings and not the more superficial elements.
Size
Smaller homes cost less to build. The entire cost of these energy upgrades can be paid for by trimming 300-400 square feet from the size of the home. I don’t know any typical family that couldn’t live in 1800 square feet instead of 2200 square feet.
These ideas are covered in much more detail here on ZEP:
Buying Power
https://zeroenergyproject.com/2017/02/10/buying-power-efficiency/
Size
https://zeroenergyproject.com/2017/03/23/zero-energy-upgrades-cost-zero-dollars/
Lending
https://zeroenergyproject.com/sell/appraisal-mortgage-strategies-zero-homes/
I can’t speak for Richard but I can give you my own costs. In 2015, I built a zero energy home in a market where the median home price was $380,000. My construction cost was $220,000, ignoring financial incentives. I kept pretty good records of my actual cost. The problem is always estimating what it would have cost to build the home to code. I estimated all the above-code features cost $34,000. This includes thick walls, blow-in insulation, air sealing, better windows, high-performance mini-split heat pump, energy recovery ventilator and 4.3 KW of solar. Tax credits and utility incentives were about $13,500. So I borrowed $20,000 more than I would have for a conventional home, making my additional monthly payment about $90. The energy model says that I would have spent $91 per month on monthly electric bills.
I’m making a buck a month. It’s not much but I’ll take it!
Roberto Muller says:
This was what I was hoping to find in the article about Rich:
“I can’t speak for Richard but I can give you my own costs. In 2015, I built a zero energy home in a market where the median home price was $380,000. My construction cost was $220,000, ignoring financial incentives. I kept pretty good records of my actual cost. The problem is always estimating what it would have cost to build the home to code. I estimated all the above-code features cost $34,000. This includes thick walls, blow-in insulation, air sealing, better windows, high-performance mini-split heat pump, energy recovery ventilator and 4.3 KW of solar. Tax credits and utility incentives were about $13,500. So I borrowed $20,000 more than I would have for a conventional home, making my additional monthly payment about $90. The energy model says that I would have spent $91 per month on monthly electric bills.”
Thanks for sharing!
Troy Hodas says:
My home is a near passive house in NY climate zone 6. Using exterior dimensions my cost was $100/square foot to build. This includes the solar panels that bring it to net zero as well as all the incentive money for the panels as well as Energy Star NYSERDA Tier 3 rebates. http://www.concretehomesmagazine.com/digital-issue/archives/09102017/html5/index.html shows a little about the home and http://passivehousebuildings.com/wp-content/uploads/2018/06/NYPH18-E-Book.pdf on page 43 (picture to be updated) … Someone commented on the ERV not being code. It’s not, but mechanical ventilation is and an ERV/HRV is the best method.
TIM MCCARTHY says:
It can done done for sure, I built a “good enough” performing home, double stud walls, spray foam, reasonable windows for 145 dollars per square foot including deck. I was architect and CM and handled all costs, so that number is accurate. great project. How much do those windows cost for say a 3 x 5 foot high casement?
Roberto Muller says:
Has anyone done for research purposes a construction of two identical houses – one to a given municipality’s code and a passive house – and done a line by line comparison of where the prices vary for the total project, including architecture and rating fees?
I would looooove to see something like that.
Ryan F says:
All- great points. Even if it’s only going to put $1/mo. in my pocket (although I think it would be more), there are still HUGE upsides- the biggest off the top of my mind: not having to import oil from terrorists overseas for a bunch more combustion heat, WAY less of a carbon footprint, leaving a better mother earth for your kids. We only get one earth, we have to evolve.
I am in the market for a builder who feels the same, and has experience building this way. If anyone knows of one near Burlington county NJ, please post their website/contact info.
Thanks
Joe Emerson says:
Please Check out our Directory of Zero Energy Building Professionals to find someone near you: https://zeroenergyproject.com/zero-energy-home-directory/
Roger says:
This is not accurate. Spoke to this builder about the most cost efficient design to be built in CT and what do you know…$300/SF. I don’t know what good it does to misinform people like this.
Richard Pedranti says:
Following our success building a cost effective PHIUS certified Passive House in Scranton, we have many inquiries about repeating this project success in other locations in North America. While there are many factors that drive construction cost including design, finishes, geometry, details, we have found that construction cost also varies considerably based on what region.
While the Scranton Passive House project cost around $165/SF, we have built a similar version in New York State with a construction cost around $400/SF and our comparable work in Connecticut is above $300/SF. However, another of our PHIUS certified Passive House projects with similar specifications to the Scranton Passive House was built by the owner for less the $135/sf. The project is located in Pennsylvania and the owner, who is a mechanical engineer, trained with PHIUS to become a Certified Passive House Builder (CPHB) during the process.
Our approach to controlling construction costs is combining an iterative design process with value engineering. It means we design, detail, specify, and engineer until we meet a budget. We don’t charge extra for this process; it is part of our design services.
The Scranton Passive House project started out with much higher costs during the initial cost estimating but through our iterative design and value engineering process we were able to bring the cost within budget. Some of the decisions that allowed for a lower construction cost in the Scranton Passive House include: a slab on grade foundation with little site work, municipal utilities, simple geometry, simple and compact mechanicals, and cost-effective finishes.
Kenneth R Tuttle says:
Does the cost of a new home built with traditional home construction methods include the additional power plants and infrastructure needed to supply them with energy? How about the cost of the next war we’ll need to fight to insure our access to energy from the Middle East? … What about the potential cost of poisoned groundwater from chemical fracking for natural gas?
I think we’re much better off giving a tax break to new construction and remodels that employ Zero-Energy design principles. Zero-Energy is a bargain when all costs are added to the base price of new home construction. … This kind of innovation should be a national priority given the proportion of total energy that buildings consume. Imagine how much better off we would be if we started building like this when the oil prices started climbing in the ’70’s.
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Grande Prairie Construction Projects says:
Passive House construction’s upfront investment may be slightly higher, but the long-term benefits far outweigh the initial expenses. With significantly reduced energy consumption and operating costs, Passive House buildings offer substantial savings over their lifespan.