We have recently completed a home in Baltimore County that earned a HERS index score of 49, which translates to home that is 51% more energy efficient than required by the building code.   Our customer found us through our listing with the BGE Energy Star for New Homes Program.  He was very interested in building an energy efficient new home and we were able to discuss a wide range of energy efficient construction specifications and educate him about a Baltimore County property tax credit that is available for energy efficient construction.

The construction cost of the home was approximately $90 per square foot and the cumulative cost of the energy efficiency features was approximately $4 per square foot.  Our energy rater used REM/Rate for the energy modeling.  The results of the software calculation indicate that the home should have a monthly utility cost of approximately $150 (gas and electric).  As the home has been rated as 51% energy efficient, the monthly utility savings should be approximately $150 or $1,800 per year if the home were to be compared to a similar home built to the minimum allowable standards.  Additionally, the home will qualify for a 50% reduction in property taxes over a three year term due to the Baltimore County High Performance Home property tax credit that is available.  We estimate that this will result in an approximate $1,000 annual savings or a total savings of $3,000 for our customer.  On a dollar for dollar comparison, our customer will break even on the energy efficiency features that were added to this home in three to four years.  On a cash flow basis comparing the financing costs of the additional cost of the home associated with the addition of the energy efficiency features  to the utility and property tax savings, our customer will be net positive in the first year of the mortgage.

The specifications of the home that impact its energy efficiency are as follows:

• Slab on grade foundation fully insulated with 2 inches of rigid foam with a total R-value of 10.
• 2 x 6 exterior walls insulated with BIBS with an R-value of 23.
• 1/2″ Dow SIS sheathing on exterior walls with an R-value of 3.
• Roof sheathing with a radiant barrier.
• Energy Star certified windows with U-values of 0.29.
• 95% AFUE gas furnace
• 16.0 SEER heat pump
• Light fixtures with CFL bulbs through out the home.

This will be the second home that we have constructed that qualifies for the Baltimore County High Performance property tax credit.

In case you are not familiar with the HERS index, here is a link to the Residential Energy Serivces Network website… http://www.resnet.us/home-energy-ratings .

If you have any questions about energy efficient new homes, please let us know.  We can be reached at jake.ruppert@rupperthomesinc.com or (410) 256-0793.

www.RuppertHomesInc.com

The Baltimore community of Locust Point lost natural gas service on Monday morning due to a construction related accident associated with the replacement of a bridge (http://www.baltimoresun.com/news/maryland/baltimore-city/bs-md-ci-gas-leak-20111107,0,98907.story).  Gas service began to be turned back on in some Locust Point homes yesterday afternoon and continues today.  Some residents in the community have been without heat, hot water and cooking since Monday morning.  I am one of those residents.  If, though, I had a solar thermal water heater, I would have continued to have access to hot water at my home.  I and my family would have continued to be able to take showers and baths, clean laundry and clean dishes all along.  I have considering this over the last several days.

About a week ago, I wrote another blog describing the benefits of solar thermal water heaters.  I won’t list them again but they revolved around financial and environmental benefits.  This past week, though, made me realize there is another benefit; quality of life.  With a solar thermal water heater, the primary heating source is the sun.  There will be times during the year that the secondary heating source, gas or electricity, will be necessary to maintain the water temperature in the tank but the vast majority of the time the sun will be that heating source.  So, the addition of a solar thermal water heater will also be a positive impact on quality of life as it will reduce the impact of losing gas service from your local utility provider.

The solar thermal water heaters that Ruppert Homes, Inc. is choosing to offer as options to our new homes does not rely on electricity.  The heat exchange process uses a passive pump without any electric pumps, controls or sensors.   (More information is available at the manufacturer’s, Sunnovations, website:  http://www.sunnovations.com/).  So, the solar thermal water heater will continue to function and provide hot water without gas or electric service to the home.  That sounds like a pretty good feature to include in a new home if you are in the market for one.

Have questions about solar thermal water systems?  Please let us know.  We can be reached at jake.ruppert@rupperthomesinc.com or (410) 256-0793.

If you are considering the purchase of a new home, please consider solar water heating.  Solar water heating will provide approximately 75% of hot water needs in our area, which is to say that these devices will reduce your cost associated with hot water by approximately 75%, month after month.  There are several types of systems but they all typically rely on using the sun to heat or maintain the temperature of water stored in a tank through a heat exchanger.  The tank used in these systems is very similar to a typical tank that would be specified in a new home.  It would include an electric or gas fired heat source to heat water during periods with little sunlight or heavily overcast days.  The tank would be connected to solar collectors which are typically mounted on a roof that is facing south.  The typical collectors for a single family home would be approximately 8′ x 8′ and would lie flush on the roof surface on a shingled roof or be mounted on a rack for a flat roof.

There are lots of good reasons why a solar water heating system should be chosen.

1)  Your monthly utility bill will be reduced and future energy price increases will be less painful for you.

2)  The use of such a system will reduce the production of green house gases.

3)  When operating, these systems are nearly silent.  If a water heater is located near finished, living space, noisy exhaust fans will not be necessary to produce hot water for a majority of the time.

4)  The best reason, though, is the availability of tax credits and grants that offset a major portion of the cost of the systems.  Federal income tax credits, Solar Renewable Energy Credits, state grants and reduced property taxes in some counties can add up to offset the cost of adding a solar water heating system to your new home by as much as 80%.

If you are interested in learning more or seeing one of these systems actually installed, Ruppert Homes will be using a solar water heating system at our new model home at The Townes at Locust Point.  The model home is expected to open in January.  We’ll be posting photos of the system as the components get installed to better provide an explanation of the system.

Let us know if you have any questions about solar water heating systems or other construction specifications of new homes by emailing us at Sales@RuppertHomesInc.com .

The custom home in Baltimore County is now complete.  As part of our service to our homeowner, we have commissioned Energy Services Group to inspect and test the home.  This auditor inspected to make sure that it complies with the requirements of the Energy Star Qualified New Home program and performed both a blower door test and a duct blaster test.  The blower door test is performed to determine how leaky a house is.  It is performed by closing all doors, windows and vents on the exterior of the house and then temporarily installing a vinyl door that includes a fan.  The fan is turned on to blow air out of the house.  Since all intended “holes”, i.e. doors, windows, etc., are closed, the amount of air that leaks back into the house can be measured.  This air is coming from joints, cracks, and leaks around the foundation, framing members, doors and windows, roof trusses, etc.  It is our goal to reduce these leaks as much as possible in order to reduce cold air infiltration during the winter and warm, humid air infiltration during the summer.  The duct blaster test is performed to determine the amount of air leakage in the duct system in the home.  Duct leaks should be avoided to reduce condensation and possible mold growth in unconditioned areas.

The result of these tests was that the home had a HERS (Home Energy Rating Score) of 58.  The HERS score represents the energy efficiency of the home.  A HERS score of 100 means that the home meets the energy efficiency required by Code.  A HERS score of 90 means that the home is 10% more  efficient that Code requires.  A 58 means that the home is 42% more efficient that Code requires.  Not only will these homeowners save a significant amount of money on their monthly utility bill, the HERS score 0f 58 qualifies this property to receive a 40% property tax reduction from Baltimore County over the next three years.  The savings from utility costs combined with the savings from the property tax credit make a significant offset in the cost of the energy efficient features that were added to this home while it was being built and will greatly reduce the overall cost of ownership of this home.

If you have any questions about the details of this custom home or would like to discuss energy efficient new construction, please feel free to contact me at (410) 256-0193 or jake.ruppert@rupperthomesinc.com .

Maryland Clean Energy is hosting a consumer trade show tomorrow, October 29th, from 9:30 to 2:30.  The show is free to the public.  For additional info.:  http://mdcleanenergy.org/summit/

The custom home under construction is spec’d to include some very high efficiency mechanical equipment.

Water heating:  The water heater is an A O Smith Vertex condensing water heater.  The advanced heat exchanger for this product has a significant impact on efficiency.  This water heater has a thermal efficiency of 0.96.  This compares to efficiencies of 0.82 to 0.84 for many gas fired, tankless water heaters that are marketed for their efficiencies.  The efficiency of the heat exchanger also allows for significant production such that this water heater outproduces larger water heaters.

Heating and Cooling:  The home is designed for two heating and cooling zones.  The lower zone includes the first floor and the unfinished basement.  The upper zone includes the second floor.  Both zones are controlled with programmable thermostats.  The lower zone includes a 95% AFUE gas furnace matched to a 18 SEER heat pump.  A heat pump was used in place of a typical air conditioner because a heat pump is actually more efficient in producing heat at mild temperatures than a gas furnace is.  The gas furnace becomes the better choice for a heat source when temperatures drop below the mid-30′s.  The thermostat that controls this zone is connected to an outdoor sensor that communicates the outdoor temperature so the thermostat can decide which of the two heat sources is the better choice during the heating season.  The upper zone includes an 18 SEER heat pump.  This heat pump was located inside a closet on the second floor for easy access for maintenance.  Often upper zone HVAC equipment are located inside attic spaces.  This choice greatly reduces the possibility that the homeowner will regularly replace or clean the filter for this hard to get to equipment.

Lighting:  Throughout the home, the light fixtures include CFL lamps to reduce both the energy demand of the fixtures and the heat produced from the fixtures.  CFL lamps are as much as 75% to 80% efficient when compared to incandescent lamps.  Much of the additional energy used by incandescent lamps is wasted as heat.  This heat source can be significant in a large house during the summertime.

The framing of the custom home in Baltimore County has been complete for a couple of weeks.  I’m taking advantage of the slow rainy morning to update the blog to discuss the framing aspects that were used for this home.

Dow SIS sheathing was chosen for the exterior sheathing.  Dow SIS does three jobs; it provides structural lateral bracing, it provides a water resistive barrier and it provides significant insulation performance.  I have recently begun to hear the term “out-sulation” and it applies to Dow SIS.  This product provides a layer of rigid foam insulation on the exterior of the stud walls and floor joists to create a “thermal break” between the exterior cold surfaces of the home and the interior structure.  This significantly reduces thermal conductivity into the home when there is a significant difference  between the outdoor and indoor temperatures.

The exterior walls are framed with 2 x 6 studs.  A 2 x 6 exterior wall increases the allowable depth of exterior wall insulation to 5.5 inches from the 3.5 inch depth that would be associated with a 2 x 4 stud wall.  This particular home, with the 2 x 6 exterior walls and Dow SIS sheathing will have exterior walls with an R value of 26, significantly higher than was is required by code (R13) and which is the typical amount of insulation used in Baltimore County.

The floor joists are engineered I-joists versus dimensional lumber, such as 2 x 10′s or 2 x 12′s.  Engineered I-joists eliminate many of the issues associated with dimensional lumber, such as the natural curvature, or crown, of the board and the tendency to warp over time.  Additionally, this product is a more efficient use of wood as it uses much less material to achieve the same results and is lighter to move, given equivalent lengths, is very easy to cut and allows for holes to be cut for future wiring or plumbing requirements.

The sub-floor sheathing is AdvanTech orient strand board (OSB).  AdvanTech is designed to outperform competing products in moisture resistance and stength and stiffness.  Moisture resistance is very important because homes are constructed in the open weather and sub-floor sheathing that is exposed to high moisture can swell, warp or delaminate.  This can cause squeaking or uneven surfaces in finished floors.

The engineered roof trusses are designed with raised heels.  A typical truss design includes a very shallow depth of insulation at the edge of the attic area, over the exterior walls.  This is due to the slope of the roof surface angling downward towards the horizontal, bottom plate of the truss.  As these two surfaces approach each other, their distance apart is reduced and therefore the available space for insulation is diminished.  Raised heel trusses are designed to provide a specific amount of distance between the sloping roof surface and the horizontal, bottom plate so a pre-determined amount of insulation will always fit.  The intent is to allow a uniform depth of insulation to be applied to the entire attic floor, even over the exterior walls.  In the photo below, the raised heel of the truss is the vertical stud set over the exterior wall.

The roof sheathing includes a radiant barrier.  The radiant barrier is a foil surface applied to the underside of the roof sheathing.  The foil surface reflects some of the heat caused by the sun beating on the roof on a sunny day.  With some of the heat being reflected away, temperature inside of the attic is dramatically lower.  The lower attic temperatures have a reduced impact on the cooling load necessary during the summer, lowering utility bills and increasing comfort.

The roof design includes both rake and eave overhangs.  The overhangs serve two purposes.  The primary purpose is to create a drip edge away from the exterior walls.  Having the drip edge away from the exterior walls increases the durability of the walls and reduces the possibility of water intrusion issues.  The secondary purpose is to create shading during summer months for windows, when the sun is high in the sky.  This reduces the heat transmission through the windows and walls which reduces utility bills and increases indoor comfort.  Adding roof overhangs is not required by building code and most builders do not add this feature as a way to save costs.  However, roof overhangs are a principle of green or sustainable construction and are supported by building science.

Once again, if you should have any questions on this or our other blogs, please let us know.  We would be happy to have a more in depth conversation about any of these topics.  We would also be happy to host a tour of this particular home while it is under construction.

Our next topic will be mechanical systems.

The Superior Wall foundation of the custom home that we are building in Baltimore County has been installed.  In the photo above, the exterior of the foundation is shown.  The foundation was constructed to include brick ties and a brick ledge on all sides to accommodate the brick veneer of the home.  The walls of the foundation were set in place over two days.  Because the concrete walls were cast in a factory setting, there is no job site waste material or clean up after installation was complete.

The above photo shows the interior side of the Superior Wall foundation.  As you can see, the interior is clad in a rigid foamboard by Dow.  The 2.5 inch foamboard provides an R value of 12.5 which exceeds the building code requirement.  Additionally, the metal faced studs are visible.  The studs are formed in the casting in the concrete wall and are clad in rigid foamboard and capped with a metal face.  Drywall can be attached directly to the metal facing to complete a finished basement area.  The studs are cast with horizontal chases to allow for future wiring needs in the foundation walls.

Next post:  Framing.

The custom home in Baltimore County is now under construction.  Excavation is complete and the foundation is expected to be installed beginning on December 1st.  The foundation type that our homeowners chose was a Superior Wall foundation by Weaver Precast.  The Superior Wall is a precast foundation wall that is cast at Weaver Precast’s facility in Ephrata, PA and then delivered and assembled on-site.  This foundation type differs from the more common “poured wall foundation” that is actually built on-site and in place.  The poured wall foundation utilizes metal forms which are poured full with concrete.  After a couple of days to allow the concrete to cure, the forms are removed and the concrete foundation is left in place.

The Superior Wall foundation is a more expensive foundation system but it has several positives when compared to poured wall foundations:

1)  Superior Wall foundations are cast with rigid insulation as a component of the wall.  In the case of this custom home, the Superior Wall foundation will include 2 1/2″ of insulation with an R value of 12.5.  The current building code requires a foundation wall to have an R value of at least 11.  To achieve this requirement with a poured wall foundation, batt or other insulation would need to be installed by another vendor at a later date.  The rigid insulation layer included in the Superior Wall foundation thermally isolates the interior space from the exterior for the entire height and length of the foundation wall.

2)  Superior Wall foundations have a compressive strength of approx. 5,000 psi.  Typically, the concrete in poured wall foundations is specified with a compressive strength of 3,500 psi.

3)  The shape of Superior Wall foundation are such that “studs” are formed into the concrete.  Galvanized steel facings are cast onto the concrete studs so that drywall can be attached directly to the foundation wall.  Access holes are cast into the concrete studs to allow for plumbing or electrical requirements.  In order to provide a finished condition within a poured wall foundation, wood stud walls are typically necessary to provide a surface to attach drywall to and to provide an area to install any required plumbing or electrical needs.

4)  Superior Wall foundations do not require further dampproofing.  In Baltimore County, poured wall foundations with a strength up to 4,000 psi require a dampproof finish on their exterior to prevent ground water from migrating through the concrete wall.  Since Superior Wall foundations exceed the 4,000 psi compressive strength specification, they are not required to be “finished” with a dampproof coating.

5)  Superior Wall foundations are cast indoors at Weaver Precast’s facility.  So, weather does not impact the pouring of the concrete and additives are not needed in the concrete mix due to cold temperatures.

Check back during the first week of December because we will be posting pictures of the Superior Wall foundation while it is being set and after it is complete.  In the meantime, if you have any questions about Superior Wall foundations or custom homebuilding in general, please contact us at sales@rupperthomesinc.com or (410) 256-0793.

An article has been posted on www.walletpop.com, a personal finance website, that indicates Locust Point is one of the safest neighborhoods in any major U. S. city.  The reported study includes data from Neighborhood Scout and FBI crime data.  The results indicate that Locust Point is safer than 70% of all neighborhoods in major cities.  The full article is available at  http://www.walletpop.com/blog/2010/11/08/safest-neighborhoods-in-americas-top-cities-2010/ .

We have heard numerous times from our homeowners how they appreciate the qualities of Locust Point; the quieter nature of the neighborhood and yet quick access to the Inner Harbor, the downtown business district, the stadiums, etc., etc..  This report just seems to back up what the homeowners intuitively feel about their neighborhood.

If you would like information about the homes or community of The Townes at Locust Point, please feel free to contact us at sales@rupperthomesinc.com or (410) 256-0793.