EcoSmart Stud 
Blue Barn Construction 1420 sq ft Rambler Home
The Build Series has been an exercise in looking at what it takes to build an Energy Star Zero Energy Home in Minneapolis, MN, climate zone 6. Build costs will vary from city to city and state to state. There are a lot of variables when it comes to building homes: offsite, onsite, size of builder, size of home, local building codes, and location. The point of the series has been to look at real costs.
The 1420 finished sq ft above grade rambler with an 1000 sq ft unfinished basement we have been using as a guide is planned to be built on an existing lot where the current home has been removed and the lot divided into two separate lots. Blue Barn Construction who intends to use the EcoSmart™ Stud in their new builds was curious to see the actual cost difference between building an Energy Star Zero Energy Ready Home (ZERH) and a standard home built to the current Minnesota Energy Code.
Now that we have walked through the difference in upgrade costs needed to meet the requirements of an Energy Star ZERH build over the past weeks, it is time to add in the complete numbers and look at the total cost to build this home to the different standards. These numbers are based on the sworn construction statement developed for this 1420 sq ft home. The lot cost is extra but estimated at $110,000. The totals are without the Energy Star and utility rebates figured in.
Current Minnesota Energy Code: $327,072
The 2021/2024 Energy Code: $329,522
Energy Star: $330,180
Energy Star ZERH: $331,557
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Cost Comparison. Upgrade cost | |||||
| Design Criteria CZ 4c-8 | ||||||
| Elements | Current Code or practice for MN Climate zone 6,7 | Energy Star | ZERH | Upgrade Cost for new home, 1400 sq ft Rambler | ||
| Energy Star | Energy Star ZERH | |||||
| Insulation Envelope | ||||||
| Ceiling | R49 | R60 | R60 | $200 | $200 | |
| Above grade exterior walls | R20 stated | R22 effective | R22 effective | $1,450 | $1,450 | |
| Foundation walls | R10 | R15 | R15 | $1,000 | $1,000 | |
| Floor insulation | R30 | R30 | R30 | n/a | n/a | |
| Slab on grade | R10 | R10 | R15 | n/a | n/a | |
| Under Slab, heated | R10 | R10 | R15 | n/a | n/a | |
| Windows | ||||||
| U-Value | 0.37 | 0.27 | 0.25 | $458 | $1,285 | |
| SHGC | 0.35 | 0.3 | 0.3 | $0 | $0 | |
| Sky lights | n/a | n/a | ||||
| Doors | ||||||
| Opaque U-value | 0.17 | 0.17 | n/a | n/a | ||
| SHGC | any | any | n/a | n/a | ||
| 1/2 light or smaller U-value | 0.3 | 0.3 | n/a | n/a | ||
| SHGC | 0.4 | 0.4 | n/a | n/a | ||
| 1/2 light or larger U-value | 0.25 | 0.25 | n/a | n/a | ||
| SHGC | 0.25 | 0.25 | n/a | n/a | ||
| Mechanical | ||||||
| Water heating | ||||||
| Electric UEF | 1 | 2.2 | 2.57 | $0 | $0 | |
| Gas UEF | 0.84 | 0.9 | 0.95 | n/a | n/a | |
| HVAC | ||||||
| Furnace AFUE | 81% | 95% | 95% | Common | Common | |
| AC SEER | 14 | 14 | 16 | n/a | $200 | |
| Boiler | 81% | 95% | 95% | n/a | n/a | |
| HSPF | 8.8 | 9.2 | 9.5 | n/a | n/a | |
| Air Source Heat Pump | 8.8 HSPF/15 SEER | 9.2 HSPF/16 SEER | 9.5 HSPF/ 16 SEER | n/a | n/a | |
| Whole house mechanical ventilation system efficiency | 1.2 CFM/W balanced 65% SRE at 32 Deg F | 1.2 cfm/W balanced 65% SRE | 1.2 cfm/W balanced 65% SRE | Code | Code | |
| All ducts and air handlers within conditioned space | x | x | x | Code/Common | Code/Common | |
| Sealed ductwork | x | x | x | Code | Code | |
| Programmable thermostat | x | x | x | Common | Common | |
| Lighting, Appliances, Other |
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| Energy star appliances. LED lighting | x | x | x | Common | Common | |
| Outlet for Heat Pump Water heater | x | n/a | $0 | |||
| Outlet for Heat Pump Furnace | x | n/a | $0 | |||
| Outlet for Car Charging | x | n/a | $350 | |||
| PV assessment | x | n/a | $0 | |||
| HERS rating | x | x | $0 | $0 | ||
| Upgrade Sub totals | $3,108 | $4,485 | ||||
With the total cost of all needed upgrades to build the Energy Star Zero Energy Ready Home being a mere ($4,485), it’s challenging to see a difference in cost. That ($4,485) upgrade cost is only 1.3% of the total build budget. An Energy Star Zero Energy Ready Home is estimated to save about $1 per sq ft in Climate Zone 6, that is about ($1420) a year in energy savings. The return on Investment (ROI) for the new homeowner for the extra cost is only about 3 years, a promising figure that indicates the financial benefits of this project if the additional costs were not offset by Energy Star and utility company rebates for building an energy-efficient home.
Now, with the lower cost of the EcoSmart™ Stud wall system, the total upgrade cost needed for the Energy Star ZERH build ($4,485.50) is less than the cost of the CI wall system estimates of ($6,868.00) for just the wall system alone! Now, the Energy Star rebates, when paired with Utility Company rebates ($11,650.00), cover the complete upgrade cost for this build including the energy raters’ costs. Those will vary depending on the rating company, we saw a range of $1500-$2500. We chose to go with MN CEE, their charges are $2300 for an Energy Star ZERH build.
We also have an additional estimated cost savings for this build of ($1750) from use the 48V DC lighting system ($1,000) and the EcoSmart™ Stud ($750) both from the electrical installation. These have been kept separate from upgrade costs but still do lower the amount of the ZERH costs.
With the EcoSmart™ Stud wall system, building an Energy Star Zero Energy Ready Home becomes a ‘why not’ decision instead of a ‘why’ decision. The cost benefits are clear, making the EcoSmart™ Stud wall system a compelling and financially sound choice for the building community and new homeowners!