Building Science Raises the Bar on This Model Home

It’s not rocket science, it’s “building science” that sets this model home apart from other floorplans that are comparable in appearance.

Like books, homes can’t always be judged by their outer façade. Building science  which is defined as a collection of scientific and technical knowledge that leads to better indoor environmental quality, energy-efficient built environments, and occupant comfort and satisfaction. The main principle of building science  is building a home as a system versus individual pieces and parts.

Since 2007, the company has been dedicated to continually improving the sustainability and durability of the green homes it builds by focusing on best building science and design practices, renewable energy systems and advanced technologies.These includes products that optimize energy efficiency and comfort for homeowners.

For Tim O’Brien Homes, it all starts with creating a super-tight, well-insulated and dry building envelope. “We’re one of only a few local builders that wraps the entire home in a kind of “thermal fleece”--one inch of rigid foam insulation on all exterior OSB engineered wood panel walls,” explains Tim O’Brien, president of award-winning Wisconsin home builder Tim O’Brien Homes.


In home construction, R-value refers to a measure of how well a layer of insulation, window, or a complete wall or ceiling keeps heat from entering or exiting a home. The basement walls of Tim O’Brien homes are insulated to R-14 using closed-cell foam in the box sills. Full foundation walls are clad on the outside with 1.5 inches (R-7.5) of foam insulation, and attics have blown insulation rated at R-50.

The final element of the tight building envelope is a complete house wrap in Tyvek, a reputable product that incorporates unique material science to help keep air and water out while letting water vapor escape. While many contractors claim to be capable of installing house wrap, Tim O’Brien Homes employs its own trusted certified Tyvek installers, who expertly tape and seal the product including all gable ends. “This ensures the integrity of the installation, and helps to avoid any warranty issues,” says Tim O’Brien.

This kind of commitment to quality extends to all aspects of building a green home. “We’ve been using the same insulator, HVAC (Heating, Ventilation & Air Conditioning), energy rater and other contractors since the very beginning,” O’Brien explains. This applies to every Tim O’Brien green home feature, product and technique, including the following:

  • Heating 95% high-efficiency furnace with digital smart thermostat
  • Energy Efficiency (in addition to insulation and house wrap):
    • "Low-E” argon gas-filled ENERGY STAR windows, which allow the sun’s energy to heat the home while preventing heat loss
    • Insulated overhead garage door with weatherstripping
    • Insulated (R15) exterior door with weatherstripping and adjustable threshold; LED lighting
  • Indoor Air Quality:
    • RenewAire Energy Recovery Ventilator (ERV), which replaces stale indoor air with fresh outdoor air, while preheating the air coming into the home in the winter, and removing heat from the home in the cooling season
    • MERV 11 HVAC air filter
    • Active Sub-Soil Venting System which prevents naturally occurring but harmful Radon gas (common in Wisconsin) from entering the home
    • Aeroseal duct air-sealing technology
    • Low VOC (Volatile Organic Compound) paints
  • Waterproofing:
    • Erosion control storm water management
    • Box footing drain tile with waterproofing membrane on foundation walls
    • 10-year dry basement guarantee
  • Water Conservation: EPA WaterSense certified water-saving plumbing fixtures
  • Recycling of construction debris
  • Durability:
    • Reinforced foundation footings and walls
    • Advanced framing techniques

Tim O’Brien calls himself a “lifelong learner”. He comes from a background in Total Quality Management, which is defined as “a continual process of detecting and reducing or eliminating errors in manufacturing, streamlining supply chain management, improving the customer experience, and ensuring that employees are up to speed with training. 

“Over the years, we have always been willing to try different things to continuously improve the performance of our homes,” he says. “When all is said and done, we go a couple of steps further to ensure that our homeowners enjoy their sustainable, comfortable and climate-resilient homes.” We balance the HVAC system, check air registers in every room (exhaust and centralized returns), and conduct a blower door test to determine how much air is entering or escaping from the home.”

Air leakage in the home is measured by ACH (Air Changes per Hour). The lower the ACH, the more air-tight the home is. A typical house in the U.S. constructed to building code measures from 3 to 5 ACH, depending on its climate zone. By contrast, a Tim O’Brien home averages an impressive 1.5 ACH.

According to Tim O’Brien Homes Director of Marketing Ryan Hillgarder, a vital component of building a green home is having homeowners on board throughout the process. “Because building science and technology is all so new to most people, it’s vital for us to educate people not only about the ‘how’, but also ‘why’ they’re important to the sustainability and health of the home,” he says. “We’re very proud of our entire team, including our sales people, for all they do to educate our homeowners on the building experience.”

The very final stage of construction involves field testing and green home certification. Whereas other builders only check a random sampling of their houses, Tim O’Brien Homes tests and certifies each and every one of its homes, with a  complete field test performed by a third-party certified professional. 

As a result, every home comes with a Green Built Home™ certification and exceeds the minimum requirements of the Wisconsin Focus on Energy™ energy efficiency and renewable resource program. Homeowners receive a certification report that shows the home's energy savings, and a Focus on Energy New Homes Certification Plaque. 

As with any green home, occupant behavior is critical to overall performance, especially when it comes to indoor air quality and comfort. To make sure that homeowners do their part in maintaining their HVAC equipment, such as regularly changing filters and cleaning certain components, Tim O’Brien staff take the occupants on an educational walk-through of their home and leave them with a homeowner’s manual and instructional video once the keys are handed over. 

“It’s not too complicated,” O’Brien says. “But it’s important–for us and for the homeowners.”

Check out photos, floor plans, and more information on the VISION House Sussex here.