Hillsdale Vally Estates

Hillsdale, N.Y.

Design Features

Project Overview:
Hillsdale Valley Estates is located in beautiful upstate New York. Only minutes from the Berkshires in Massachusetts these homes will be built on rolling open and forested hills. The first of these homes is a passive solar assisted New England Saltbox. The structure will be a Habitat kit home modified to incorporate passive solar. During the winter, the home will gently warmed by the sun while a geothermal heat system can be used on colder or cloudy days. In summer, natural ventilation will purge the home of heat. Air conditioning can also be provided by the geothermal system on the hottest of days. To minimize the home’s need for supplemental heating or cooling, we are focused on building a tight envelope, including wrapping the exterior with a layer of foam. A rain screen will be added to the exterior, followed by locally sourced natural wood siding. The interior finishes will be low or no VOC paints and natural clay plaster. The flooring will be a combination of ceramic tile and locally sourced and sustainably harvested wood with low VOC finishes. We have designed this home to have clean indoor air, natural light, local materials, even, consistent, efficient heat and cooling, cooling summer breezes, expansive southern views, natural landscaping, and a strict site and construction management plan.

Habitat Kit
Habitat kit homes are a Green choice for a number of reasons. Materials can be purchased in bulk by the manufacturer, and can be more accurately sized than in on-site construction. This results in less waste and reduced cost. Habitat also purchases all their Douglas fur timbers from a sustainably managed, family run mill. These homes are highly insulated and use a system that significantly outperforms conventional framing, even when the “R-values” of the insulation are the same. This efficiency is achieved by putting a layer of rigid foam insulation around the entire exterior of the house. When sealed properly this layer of foam stops air infiltration and greatly reduces thermal bridging between the exterior of the home and its indoor environment. Eliminating thermal bridging is an effective way to minimize heat loss. With interior framing material purchased from well managed source, the Habitat kit home is a great sustainably home.

Passive Solar
Passive solar heating techniques have been around for centuries and can supply a home with up to 80% of its annual heating needs depending on its location and design. The home was designed with passive solar heating and cooling in mind. The southern exposure of the home has added solar glazing to allow for more solar gain within the home. To maximize the heating power of the sun at certain times of year, a carefully calculated volume of thermal mass has been added to areas of the rooms where the sun hits directly. To maximize the benefits of passive solar heating, careful window selection is crucial. Another important feature of a well-functioning passive solar system is window overhangs, which protect the home from unwanted summer heat gain. Overhangs need to be properly sized based on the latitude and heating requirements of the home. The objective is to allow sun to enter the home during the colder seasons and block it from entering during the warmer months of the year. In order to shade the first floor windows, we added overhangs above the windows across the south facade.

Local Materials:
Incorporating local materials has several benefits to a project as well as the environment. Using these materials can reduce the carbon footprint of the building by reducing the distance that materials are transported between harvest, manufacturing and delivery, and also can help support the local economy. Locally sourced Douglas fur interior trim, rustic wide plank flooring, wood siding and regionally salvaged brick will tie this home to its location and reduce the environmental impact of its construction.

Site and Construction Management Plan:
We have developed a strict site management plan to ensure that the construction process does not negatively impact the surrounding natural ecology. For example, it is important for the natural eco-system to be protected from soil compaction caused by heavy equipment traffic. When soil is compacted its ability to allow water to percolate is restricted as well as the amount of oxygen in the soil, which negatively affects the soil’s ability to support both plant and animal life. In this case, managing the construction site means setting up and enforcing disturbance boundaries to protect plants, animals and the natural hydrology of the site. Boundaries are established that limit construction traffic to within a certain distance from the building perimeter, driveway edge, road edge, etc. Strict guidelines are set for all contractors to follow, with specific requirements to ensure that the building is constructed according to the home owner’s specifications.  This plan includes requirements for building envelope performance, waste management practices, material specifications, indoor air quality, general construction and materials handling, etc.

Geothermal:
For this home we chose a geothermal system to supplement the passive solar design. Working closely with the HVAC engineers we have designed a system that works in conjunction with the passive solar design to provide heat only when and where it’s needed. The environmental and financial befits made geothermal heat the perfect choice for this project. The main benefit is that geothermal systems require no fossil fuels freeing the owner from concerns over increasing gas costs.

Energy Efficiency:
Energy efficiency is the backbone of any Green home. A tight envelope and quality insulation are the first steps to ensuring energy efficiency. For this home, we have set air infiltration limits that will be tested using a blower door to ensure that the building performs according to the design standards. A blower door is essentially a large fan that is set up in a doorway. It is connected to a computer allowing accurate infiltration rates to be measured. Checking air infiltration before closing in or insulating the walls will allow for a much tighter envelope and a more energy efficient structure. Insulation will then be installed and checked for air infiltration before sheetrock is installed. This step is also helpful for achieving energy efficiency since a quarter inch gap between a wall stud and standard fiberglass insulation results in a 25% drop in the R-value of the insulation. High efficiency windows and doors will complete the package.

Indoor Air Quality:
Consideration of indoor air quality has becoming more important as the effects of poor indoor air quality are realized. For example, Volatile Organic Compounds (VOCs) are found in many products typically used in house construction. Toxins (such as VOCs) in the air that are offgassed by materials in the home can contribute to eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Because of this we have specified that products used in this project contain as few VOCs as possible. 
In order to ensure good indoor air quality in a building this air tight, it is important to bring in outside air in a controlled manner to keep oxygen levels up and toxins down.  Controlling the amount and temperature of the air that enters the house allows heating efficiency to be maintained while achieving proper ventilation. Outdoor air entering the house is heated up using a heat recovery ventilator (HVR). This technology takes the warm outgoing air and runs it past the cold incoming air allowing the heat to transfer from one to the other often with greater than 60% efficiency.

Site Design: Yellow Pants Studio