New Passive Solar Home Design Consulting
Home Site Analysis
The couple have horses and would like the pasture and barn to be located to the east of the home. A clearing for the pasture had already been completed, and the home’s main living area was planned to face east toward the pasture.
Knowing that the couple had already purchased their home plans and could only make simple changes, we looked at aspects of the home and the siting of the home that could easily be completed, yet have large, lasting impacts. The first thing to decide was how many degrees off of true south could the home face to still gain a large percentage of passive and active (solar thermal panels will also be installed) solar gain.
A home can face up to 22 degrees off of true south and still retain a large percentage of solar gain. By angling the home toward the east, and the pastures, the home could benefit from passive solar gain and still be able to look out at their pasture.
Time-of-use room design
The family’s lifestyle - their passions and pursuits, and their day-to-day needs were analyzed. The following key aspects were discussed:
The kitchen/dining/living area formed a large great-room on the east side of their home. The living room was in the northeast corner, the dining area in the southeast corner, and the kitchen on the south side, just west of the dining area. This entire area was to be the 2-story high large opening. The couple love to cook, and enjoy watching their horses, which is why they wanted all main living areas on the east side of the home.
The northeast corner of a home is the coldest area, and tends to be the darkest area past mid-day. Having the living room in this corner, when it will be only used toward the evenings, will result in a dark and cold place to relax. Also, the positioning of the 2-story high opening is not only low-energy efficient, but it will be almost impossible to keep warm. A good solution to this is to have the kitchen in this area, since the warmth of the cooking can nicely heat up this space.
The 2-story high opening was enlarged to secure the mortgage, but plans could be created to enclose this area with more living space in the future. Structural girders could be built into the home that could look decorative, post & beam style, until funds can be later obtained for partially enclosing the opening. It is always best to build in these details in the beginning, versus add them in years later. Also, by decreasing this large opening, it will make the space more manageable for heating and cooling.
The main entry-way entered directly into the living room, with no mudroom or areas to hang coats/boots/hats etc.
A home in the northeast should have an area dedicated to receiving all muddy and/or wet shoes and outerwear, and is best to be closed off from the main house to limit the heat/cold from escaping in the winter/summer. The Freemans were able to move closets and slightly decrease a bedroom’s area to obtain a nicely designed mudroom.
Day-lighting and natural ventilation techniques
The large 2-story living space could be made more energy-efficient by strategically placing windows to create good natural ventilation.
The larger the distance in height are the windows, the larger the exchange of air will be, due to natural air convections. By placing windows high up in this space, that could be opened during the summer, cool breezes will be drawn into the space, cooling the home.
Structural engineering services
The structure of a home can also make a home more energy efficient, by producing less waste or using fewer resources. The structure of the Freeman’s residence was analyzed and there were a few areas that could be improved to bring down costs.
The northwest corner of the home was inset, creating three building corners. Creating this type of foundation, and the additional framing required for this detail adds unneeded costs. By creating a four-sided foundation, and by “bumping-out” the building’s framing to create a four-sided structure, will increase the home’s square footage without increasing the materials needed, and yet will decrease the costs for framing. Also, if roof trusses are used, which can be quite cost-effective, then all trusses can be uniform, saving additional funds.
The Freeman’s did not have a fireplace shown on their plans, since they didn’t have the funds for one. A masonry fireplace, however, adds much thermal mass to a building, which is crucial to a good passive solar design. If a masonry fireplace was desired for the future, the foundation could be built, and any framing for future openings could be framed-out as well, all for very little extra cost.
The structure for the future 2nd floor living space discussed above could have the main beams and posts framed out now. This framing could also be beneficial by having a bearing wall/frame near the mid-span of the home, which could decrease costs of the roof trusses. Instead of the roof trusses needing to span over 30’-0”, they would only need to span 15’ to 20’, thus decreasing costs.
The Milovia Group™ Sustainable Engineering and Design Strategies Copyright 2010