Thrive Home Builders’ latest townhome tackles challenges such as affordability, growing families, and disaster resistance
Thrive Home Builders of Colorado has reached new heights with its E-PWR Volt Townhomes at Loretto Heights, in Denver. Perched high on a hilltop southwest of downtown, the historic site is once again once again making history as the site of one of Thrive’s most energy-efficient communities.
The 148 townhomes and 140 single-family homes by Thrive meet all of the high performance criteria of the U.S. Department of Energy (DOE)’s Zero Energy Ready Home (ZERH) program. They offer a high level of energy efficiency, sustainability, health, and cost effectiveness for local home buyers.
The townhome’s modern aesthetic includes flat and pitched roofs, and composite wood lap siding along with patches of red brick—a nod to the former campus of historic 19th century Loretto Heights College.
The regional builder of single-family and multi-family market-rate and affordable homes also achieved a DOE ZERH Innovation Grand award on the townhomes. With a Home Energy Rating System (HERS) score of minus 1, the winning home should provide its first-time homebuyers with near-zero energy bills for years to come.
“Thrive’s slogan is ‘Homes that do more,’” says Bill Rectanus, Thrive’s vice president for operations. “This ‘do more’ townhome shows how it can accommodate growing families, pay for its own energy, improve the health and comfort of its occupants, and play an important role in disaster resistance.” Thrive has achieved a home with an annual energy bill of $7 using readily available materials and simple construction methods that any builder and any subcontractor can reliably execute, Rectanus adds. Through its groundbreaking performance and durability, “it can also be the best investment of its owners’ lives.”
Like all homes certified through the voluntary DOE program, the home has ENERGY STAR Version 3.2 and EPA Indoor AirPlus home certifications, and the latest energy codes as its baseline, providing its home buyers with the health, resiliency, and utility bill savings these programs offer.
“This home serves as a template that will be replicated dozens of times in the future within Thrive’s Loretto Heights community,” says Rectanus. The townhome is one of 92 three-story townhomes, 56 two-story townhomes, and 140 single-family homes (288 total) that will circle the hilltop, which provides commanding panoramic views of downtown Denver and the surrounding mountains and prairies.
Easy on the Eyes
The townhome’s modern aesthetic includes flat and pitched roofs. There is also composite wood lap siding along with patches of red brick. This is a nod to the historic red brick buildings on the site, the former campus of Loretto Heights College, founded by the Catholic order of the Sisters of Loretto in the 1880s.
While the site was sold to a local developer in 2018, many of the historic structures have been retained and repurposed as community buildings or affordable housing.
Beneath the modern façade of Thrive’s townhomes, the builder showed how its focus on quality management yielded high performance results via mostly traditional methods.
The builder achieved R-23 walls with 2-by-6, 16-inch on-center construction that incorporated advanced framing techniques such as three-stud insulated corners, open and insulated headers, and ladder blocking at interior wall intersections that allowed more room for the dense-packed fiberglass.
Half-inch structural OSB sheathes the walls and, according to Rectanus, “expensive rain screen systems were replaced with low-cost corrugated draining housewrap.” The builder followed a total UA performance path rather than prescriptive path, which enabled him to meet the overall insulation level specified by the 2021 International Energy Conservation Code (a program requirement) and avoid the need for exterior rigid insulation.
The wall’s insulation performance was maximized through the use of extensive traditional air sealing methods, such as a top plate gasket at the ceiling-to-attic interface, foam sealant at electrical boxes and the bottom plate of exterior walls, taping of all house wrap seams, tape flashing around doors and windows, and gaskets around all exterior wall penetrations.
For an extra measure of air sealing, the builder used a whole-house aerosolized acrylic air sealant process that helped bring the three-story home’s overall air leakage down to 2.92 air changes per hour at 50 Pascals of pressure.
The home designs used a standard vented attic with R-60 of blown-in fiberglass insulation. The truss design incorporated 14-inch raised-heel trusses providing plenty of space for insulation over the exterior-wall top plates. Roofs were topped with ¾-inch OSB, a self-adhered membrane, and asphalt shingles.
The foam-wrapped slab-on-grade foundations reduce excavation costs and concerns about radon. Since the Denver area has high potential for radon, an active radon mitigation system was also installed. This includes a simple manometer indicator o provide homeowners with easy verification of system performance.
Moderately priced vinyl-framed windows with a higher-performance glass unit and an insulation value of U-0.25 complete the building envelope.
Safety Searches
In Denver’s litigious housing market, Thrive took the unusual step of hiring a third-party inspector who is well known as an expert witness for homeowner associations that sue builders for construction defect claims.
Among the many extra steps of inspection, the reviewer subjected the townhome to water-resistance testing using the ASTM-E1105 test method, which involves putting the home in negative pressure while spraying high pressure water at the windows and wall penetrations after flashing and house wrap have been installed but before siding is put on to test for leaks.
“This rigorous testing is done in addition to normal building inspections, inspections by our energy rater partner, and Thrive’s own quality assurance system,” says Rectanus. “It not only reduces Thrive’s risk of construction defects slipping through our multi-step inspections, but also provides a ‘belt and suspenders’ approach to delivering a home of superior quality, durability, and performance to our homeowners.”
The top two floors of the home are heated and cooled with a central ducted air source heat pump with a heating efficiency of 10.7 HSPF efficiency and a cooling efficiency of 22.4 SEER, with electric resistance for emergency backup. Thrive also installed a ductless heat pump in the ceiling of the lowest floor.
For hot water, Thrive installed an efficient heat pump water heater. With space at a premium in the townhome, Thrive worked with the manufacturer to plan adequate incoming air to the small utility closet housing the water heater through an air-transfer grill and undercut in the closet door. They also ducted the cold exhaust air outside through the exterior wall.
A 5.2-kW roof-mounted solar array helps to produce enough electricity to net the home owners near-zero energy bills over the course of the year. This moved the HERS rating for the home from a very efficient 41 to a stellar minus 1. A mobile application provided with the panels allows homeowners to track their energy consumption and production. The PV panels can also help power the homeowner’s transportation via the 220-volt electric vehicle power charger installed in the garage.
“The path for achieving our purpose is and has been the path towards continuously improved DOE ZERHs. Beginning with our first DOE Grand Winner in 2013, we have focused on improving the energy performance of our homes, their indoor air quality, and their resilience—all at prices that everyday homeowners can afford,” says Rectanus. “With high mortgage interest rates and a median new home price in Denver of $650,000, Thrive must be focused on affordability. For us, building a better home does cost more, but this cost is offset by the lower monthly cost of ownership Thrive provides its homeowners thanks to $0 utility bills.”
The energy savings have a present value of almost $40,000, which gives homeowners $40,000 more in buying power, Rectanus notes.
Educating the Masses
Thrive has sought to assist other builders in achieving DOE ZERH standards by assisting in development of online and in person-training with the Energy and Environmental Building Alliance (EEBA); as a founding member of the EEBA Builder Benchmark Group; through seminars, presentations and trainings conducted at the National Renewable Energy Laboratory, the South by Southwest Conference, and the Home Builders Association of Metro Denver; through the RESNET and Zonda podcasts; and as a frequent contributor to construction industry trade publications.
Thrive is constructing its second ProBuilder Idea Home featuring DOE ZERH, Indoor AirPlus, ENERGY STAR Next Gen, and LEED certifications. It has collaborated with Xcel and the Colorado Public Utilities Commission in setting rebate and certification standards.
Thrive currently is the Xcel Energy All-Electric and Mixed-Fuel Builder of the Year. The company is an active contributor to the education of future leaders, through its participation as the longest serving judge in the DOE Solar Decathlon Student Design Competition and as a frequent collaborator with the University of Denver Real Estate and Construction Management programs.
Thrive’s efforts have been recognized with more DOE Housing Innovation Awards and Grand Awards than have been won by any other builder. It has also been recognized with the Pacific Coast Builders Conference Gold Nugget Award Home of the Year, the Best in American Living Platinum Award, the Best in Green Awards at the International Builders Show, and the RESNET Presidents Award and Cross Border Challenge twice as the most energy-efficient production builder in the U.S. and Canada, most recently in 2023.
Despite the successes, Rectanus notes that Thrive must still be cost competitive with national builders who construct just to code and who can spread losses across multiple markets when meeting the challenges of Denver’s high prices and lagging sales.
“If anything,” says Rectanus, “the challenging market and competition have pushed Thrive to double-down on everything we do to make a better, healthier, more efficient, more comfortable, more resilient, and more cost-effective home.”
ENERGY STAR-labeled lighting and WaterSense-certified plumbing fixtures could save a homeowner more than $3,200 per year on electricity and water usage.
Key Features
Air sealing: 2.92 ACH50; bottom plate and electrical boxes foam sealed; top plate gaskets; polypropylene gaskets for exterior wall penetrations; draining house wrap taped; windows tape flashed; whole house aerosolized acrylic sealant. Appliances and lighting: ENERGY STAR appliances and lighting. Attic: Vented attic: 16-inch R-60 blown-in fiberglass; 14-inch raised-heel energy truss. Energy management system: Indoor air quality and solar power monitoring. Foundation: Slab on grade; R-10 rigid foam along perimeter; R-68 blown fiberglass in first-floor joists. Hot water: Heat pump water heater, 65 gallon, 3.55 UEF, in 9-square-foot closet with transfer grill and door undercut and ducted exhaust. Demand recirculation. HVAC: Central air-source heat pump, 9.5 HSPF, 23 SEER2. Roof: Gable truss roof, 3/4-inch OSB, ice and water shield membrane, synthetic underlayment, composite shingles. Solar: 5.2 kW, no battery. Ventilation: Fan-powered supply ventilation balanced to exhaust fans; humidity sensors; active radon mitigation system. Walls: 2-by-6 16-inch o.c., advanced framed, R-23 total: 5.5-inch R-23 blown fiberglass, 1/2-inch OSB, draining house wrap, composite wood siding. Windows: Double-pane windows, U=0.25, SHGC=0.3. Other: Electric vehicle charger. Extensive in-house quality management and training.
Alan Naditz is managing editor of Green Builder Magazine. He has covered numerous industries in his extensive career, including residential and commercial construction, small and corporate business, real estate and sustainability.
Resilient Trifecta
Thrive Home Builders’ latest townhome tackles challenges such as affordability, growing families, and disaster resistance
Thrive Home Builders of Colorado has reached new heights with its E-PWR Volt Townhomes at Loretto Heights, in Denver. Perched high on a hilltop southwest of downtown, the historic site is once again once again making history as the site of one of Thrive’s most energy-efficient communities.
The 148 townhomes and 140 single-family homes by Thrive meet all of the high performance criteria of the U.S. Department of Energy (DOE)’s Zero Energy Ready Home (ZERH) program. They offer a high level of energy efficiency, sustainability, health, and cost effectiveness for local home buyers.
The townhome’s modern aesthetic includes flat and pitched roofs, and composite wood lap siding along with patches of red brick—a nod to the former campus of historic 19th century Loretto Heights College.
The regional builder of single-family and multi-family market-rate and affordable homes also achieved a DOE ZERH Innovation Grand award on the townhomes. With a Home Energy Rating System (HERS) score of minus 1, the winning home should provide its first-time homebuyers with near-zero energy bills for years to come.
Thrive has achieved a home with an annual energy bill of $7 using readily available materials and simple construction methods that any builder and any subcontractor can reliably execute, Rectanus adds. Through its groundbreaking performance and durability, “it can also be the best investment of its owners’ lives.”
Like all homes certified through the voluntary DOE program, the home has ENERGY STAR Version 3.2 and EPA Indoor AirPlus home certifications, and the latest energy codes as its baseline, providing its home buyers with the health, resiliency, and utility bill savings these programs offer.
“This home serves as a template that will be replicated dozens of times in the future within Thrive’s Loretto Heights community,” says Rectanus. The townhome is one of 92 three-story townhomes, 56 two-story townhomes, and 140 single-family homes (288 total) that will circle the hilltop, which provides commanding panoramic views of downtown Denver and the surrounding mountains and prairies.
Easy on the Eyes
The townhome’s modern aesthetic includes flat and pitched roofs. There is also composite wood lap siding along with patches of red brick. This is a nod to the historic red brick buildings on the site, the former campus of Loretto Heights College, founded by the Catholic order of the Sisters of Loretto in the 1880s.
While the site was sold to a local developer in 2018, many of the historic structures have been retained and repurposed as community buildings or affordable housing.
Beneath the modern façade of Thrive’s townhomes, the builder showed how its focus on quality management yielded high performance results via mostly traditional methods.
The builder achieved R-23 walls with 2-by-6, 16-inch on-center construction that incorporated advanced framing techniques such as three-stud insulated corners, open and insulated headers, and ladder blocking at interior wall intersections that allowed more room for the dense-packed fiberglass.
Half-inch structural OSB sheathes the walls and, according to Rectanus, “expensive rain screen systems were replaced with low-cost corrugated draining housewrap.” The builder followed a total UA performance path rather than prescriptive path, which enabled him to meet the overall insulation level specified by the 2021 International Energy Conservation Code (a program requirement) and avoid the need for exterior rigid insulation.
The wall’s insulation performance was maximized through the use of extensive traditional air sealing methods, such as a top plate gasket at the ceiling-to-attic interface, foam sealant at electrical boxes and the bottom plate of exterior walls, taping of all house wrap seams, tape flashing around doors and windows, and gaskets around all exterior wall penetrations.
For an extra measure of air sealing, the builder used a whole-house aerosolized acrylic air sealant process that helped bring the three-story home’s overall air leakage down to 2.92 air changes per hour at 50 Pascals of pressure.
The home designs used a standard vented attic with R-60 of blown-in fiberglass insulation. The truss design incorporated 14-inch raised-heel trusses providing plenty of space for insulation over the exterior-wall top plates. Roofs were topped with ¾-inch OSB, a self-adhered membrane, and asphalt shingles.
The foam-wrapped slab-on-grade foundations reduce excavation costs and concerns about radon. Since the Denver area has high potential for radon, an active radon mitigation system was also installed. This includes a simple manometer indicator o provide homeowners with easy verification of system performance.
Moderately priced vinyl-framed windows with a higher-performance glass unit and an insulation value of U-0.25 complete the building envelope.
Safety Searches
In Denver’s litigious housing market, Thrive took the unusual step of hiring a third-party inspector who is well known as an expert witness for homeowner associations that sue builders for construction defect claims.
Among the many extra steps of inspection, the reviewer subjected the townhome to water-resistance testing using the ASTM-E1105 test method, which involves putting the home in negative pressure while spraying high pressure water at the windows and wall penetrations after flashing and house wrap have been installed but before siding is put on to test for leaks.
“This rigorous testing is done in addition to normal building inspections, inspections by our energy rater partner, and Thrive’s own quality assurance system,” says Rectanus. “It not only reduces Thrive’s risk of construction defects slipping through our multi-step inspections, but also provides a ‘belt and suspenders’ approach to delivering a home of superior quality, durability, and performance to our homeowners.”
The top two floors of the home are heated and cooled with a central ducted air source heat pump with a heating efficiency of 10.7 HSPF efficiency and a cooling efficiency of 22.4 SEER, with electric resistance for emergency backup. Thrive also installed a ductless heat pump in the ceiling of the lowest floor.
For hot water, Thrive installed an efficient heat pump water heater. With space at a premium in the townhome, Thrive worked with the manufacturer to plan adequate incoming air to the small utility closet housing the water heater through an air-transfer grill and undercut in the closet door. They also ducted the cold exhaust air outside through the exterior wall.
A 5.2-kW roof-mounted solar array helps to produce enough electricity to net the home owners near-zero energy bills over the course of the year. This moved the HERS rating for the home from a very efficient 41 to a stellar minus 1. A mobile application provided with the panels allows homeowners to track their energy consumption and production. The PV panels can also help power the homeowner’s transportation via the 220-volt electric vehicle power charger installed in the garage.
“The path for achieving our purpose is and has been the path towards continuously improved DOE ZERHs. Beginning with our first DOE Grand Winner in 2013, we have focused on improving the energy performance of our homes, their indoor air quality, and their resilience—all at prices that everyday homeowners can afford,” says Rectanus. “With high mortgage interest rates and a median new home price in Denver of $650,000, Thrive must be focused on affordability. For us, building a better home does cost more, but this cost is offset by the lower monthly cost of ownership Thrive provides its homeowners thanks to $0 utility bills.”
The energy savings have a present value of almost $40,000, which gives homeowners $40,000 more in buying power, Rectanus notes.
Educating the Masses
Thrive has sought to assist other builders in achieving DOE ZERH standards by assisting in development of online and in person-training with the Energy and Environmental Building Alliance (EEBA); as a founding member of the EEBA Builder Benchmark Group; through seminars, presentations and trainings conducted at the National Renewable Energy Laboratory, the South by Southwest Conference, and the Home Builders Association of Metro Denver; through the RESNET and Zonda podcasts; and as a frequent contributor to construction industry trade publications.
Thrive is constructing its second ProBuilder Idea Home featuring DOE ZERH, Indoor AirPlus, ENERGY STAR Next Gen, and LEED certifications. It has collaborated with Xcel and the Colorado Public Utilities Commission in setting rebate and certification standards.
Thrive currently is the Xcel Energy All-Electric and Mixed-Fuel Builder of the Year. The company is an active contributor to the education of future leaders, through its participation as the longest serving judge in the DOE Solar Decathlon Student Design Competition and as a frequent collaborator with the University of Denver Real Estate and Construction Management programs.
Thrive’s efforts have been recognized with more DOE Housing Innovation Awards and Grand Awards than have been won by any other builder. It has also been recognized with the Pacific Coast Builders Conference Gold Nugget Award Home of the Year, the Best in American Living Platinum Award, the Best in Green Awards at the International Builders Show, and the RESNET Presidents Award and Cross Border Challenge twice as the most energy-efficient production builder in the U.S. and Canada, most recently in 2023.
Despite the successes, Rectanus notes that Thrive must still be cost competitive with national builders who construct just to code and who can spread losses across multiple markets when meeting the challenges of Denver’s high prices and lagging sales.
“If anything,” says Rectanus, “the challenging market and competition have pushed Thrive to double-down on everything we do to make a better, healthier, more efficient, more comfortable, more resilient, and more cost-effective home.”
ENERGY STAR-labeled lighting and WaterSense-certified plumbing fixtures could save a homeowner more than $3,200 per year on electricity and water usage.
Key Features
Air sealing: 2.92 ACH50; bottom plate and electrical boxes foam sealed; top plate gaskets; polypropylene gaskets for exterior wall penetrations; draining house wrap taped; windows tape flashed; whole house aerosolized acrylic sealant.
Appliances and lighting: ENERGY STAR appliances and lighting.
Attic: Vented attic: 16-inch R-60 blown-in fiberglass; 14-inch raised-heel energy truss.
Energy management system: Indoor air quality and solar power monitoring.
Foundation: Slab on grade; R-10 rigid foam along perimeter; R-68 blown fiberglass in first-floor joists.
Hot water: Heat pump water heater, 65 gallon, 3.55 UEF, in 9-square-foot closet with transfer grill and door undercut and ducted exhaust. Demand recirculation.
HVAC: Central air-source heat pump, 9.5 HSPF, 23 SEER2.
Roof: Gable truss roof, 3/4-inch OSB, ice and water shield membrane, synthetic underlayment, composite shingles.
Solar: 5.2 kW, no battery.
Ventilation: Fan-powered supply ventilation balanced to exhaust fans; humidity sensors; active radon mitigation system.
Walls: 2-by-6 16-inch o.c., advanced framed, R-23 total: 5.5-inch R-23 blown fiberglass, 1/2-inch OSB, draining house wrap, composite wood siding.
Windows: Double-pane windows, U=0.25, SHGC=0.3.
Other: Electric vehicle charger. Extensive in-house quality management and training.
By Alan Naditz
Alan Naditz is managing editor of Green Builder Magazine. He has covered numerous industries in his extensive career, including residential and commercial construction, small and corporate business, real estate and sustainability.Also Read