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The Taft School Faculty Home

Last modified by the author on 07/10/2016 - 15:43
  • Building Type : Isolated or semi-detached house
  • Construction Year : 2014
  • Delivery year : 2015
  • Address 1 - street : 06795 WATERTOWN, USA
  • Climate zone : [Dfb] Humid Continental Mild Summer, Wet All Year

  • Net Floor Area : 361 m2
  • Construction/refurbishment cost : 597 554 €
  • Number of Dwelling : 1 Dwelling
  • Cost/m2 : 1655.27 €/m2

Certifications :

  • Primary energy need
    44.3 kWhpe/m2.year
    (Calculation method : Other )
Energy consumption
Economical buildingBuilding
< 50A
A
51 à 90B
B
91 à 150C
C
151 à 230D
D
231 à 330E
E
331 à 450F
F
> 450G
G
Energy-intensive building
This home is an excellent example of design and construction for temperate climates and energy conservation. The Taft School faculty home serves as a high performance residence and learning lab for students. In US climate zone 5, it achieved a HERS 33 excluding PV and with the 13.1 kW the HERS index is -14. Located on a quiet street adjacent to campus the existing, historic home was deconstructed and salvageable materials were donated or reused. Challenged to find high efficiency windows that were historic commission acceptable, the team installed Klearwall awnings or casements over fixed glass (to mimic double hungs) with simulated divided lites (u-values as low as 0.13). A high solar heat gain coefficient (0.58) facilitates the passive solar gain for winter months, while well designed overhangs and pergola shade summer sun. Double stud walls have 2¼” closed cell foam plus 8½” dense pack cellulose for a R-49 cavity. The exterior sheathing is R-6.6 Zip Wall System with taped seams to create the continuous air barrier. Inside the solid concrete foundation is 3” closed cell foam behind 2x4 stud walls and R-32 cellulose in the cavity. Prefabricated TJI joists frame the attic floor, an insulated “room” houses the heat recovery ventilator and ductwork, and blown in cellulose blankets it all in R-86. The house tested 0.6ACH50 proving the effectiveness of its air-tight envelope and attention to air sealing. Heating and cooling is provided by efficient air source heat pumps (9.2 HSPF, 16.5 SEER) and delivered by short duct runs which tested extremely tight. A heat pump water heater provides domestic hot water and an on-demand switch, with an occupancy sensor at each bath, ensures hot water is delivered fast and efficiently. Low flow fixtures are WaterSense certified, appliances are Energy Star labeled, and all LED lighting. A Zehnder Novus 300 (93.3% efficient) HRV supplies 112 cfm of continuous fresh air ventilation; using only 32 watts of power and runs quietly. The homeowners control the mechanical ventilation through the intuitive wall-mounted control pad to shut off or increase the ventilation. Chemicals and contaminants were reduced by using low VOC and GreenGuard certified sealants, adhesives, primers, and paints. A walk-off matt at the side entry and hardwood floors help control dirt and dust. Storm water runoff from the roof, patio, and driveway is managed by the rain garden and native landscaping is low maintenance. Taft School Director of Environmental Stewardship, Carly Borken has used the design and construction process as a teaching tool for her science classes. With access to the home monitoring system they can virtually access the homes consumption. After 12 months of utility bills the home has produced 9,868 kW more than it’s used.

Stakeholders

Contracting method

General Contractor

Type of market

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If you had to do it again?

The attic air sealing and insulation would have been implemented differently. Spray foam was avoided so the thermal barrier at the attic floor made duct runs and air sealing more difficult.

Building users opinion

https://www.youtube.com/watch?v=YGlG2LmvEl4

Energy consumption

  • 44,30 kWhpe/m2.year
  • 76,00 kWhpe/m2.year
  • Other

    Above values are in MMBtu/yr
    Heating 5.9 MMBtu/yr,
    Cooling 4.9 MMBtu/yr,
    Water Heating 3.5 MMBtu/yr,
    Lights & Appliances 27.1 MMBtu/yr,
    Photovoltaics -58.6 MMBtu/yr

Envelope performance

  • 0,10 W.m-2.K-1
  • Above Grade Walls U=0.017, Windows U=0.175, Attic U= 0.011

  • 0,12
  • I4

  • 0,44
  • Site Sage Monitoring System
    Provides up to 24 electrical circuits to be monitored with web interface; 12 Lutron Radio Ra2 lighting circuits with 2 hybrid keypads; iPad Mini, and in wall docking station. Will act as a central control and monitoring location; Provides temperature and humidly monitoring of HVAC System.
    Zehnder Novus 300 is over ridden at central control pad.

Real final energy consumption

    -17,20 kWhfe/m2.year

    2 015

Systems

    • Heat pump
    • Heat pump
    • VRV Syst. (Variable refrigerant Volume)
    • Double flow heat exchanger
    • Solar photovoltaic
  • 142,00 %

Smart Building

    Since this is a single family residence there is only remote access and monitoring controls through Site Sage and Zehnder

Urban environment

    Located on an existing educational property close to community resources both on campus and in town.

  • 1 440,00 m2
  • 100,00 %

Product

    Klear Wall Windows

    Klearwall Industries

    203-689-5404

     http://klearwall.com/newsite/

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    All our products are engineered with precision and crafted with care to ensure our customers get a superior quality product. Both of the domestic and commercial product ranges are suitable for passive house construction and have been certified by the Passivhaus Institut in Darmstadt, Germany

    Combining fixed windows with awnings or casements enabled the team to mimic a double hung and get approval by the local historic commission.


    ZIPS Insulated Sheathing

    Huber Engineered Woods

    [email protected]

     http://www.huberwood.com/contact-us

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    For installation convenience and exceptional, long-term performance, the all-in-one ZIP System® R-Sheathing panel provides a new approach to sealing and insulating the building envelope. One panel delivers thermal, air and moisture resistance, while providing excellent strength and durability.

    Double s2x4 studs with 3 1/2" gap already reduced thermal bridging for above grade walls but ZIPS insulated sheathing was chosen for added thermal break plus the long term performance of the sheathing.

Construction and exploitation costs

  • 50 116,00
  • 597 554
  • 7 913

Energy bill

  • 203,00

Indoor Air quality

    Indoor airPlus Certified

GHG emissions

  • -1,20 KgCO2/m2/year
  • REM/Rate Modeling Software CO2 -1.2 tons/yr, SO2 -1.7 lbs/yr, NOx -1.6 lbs/yr

Reasons for participating in the competition(s)

​This home is an excellent example of design and construction for temperate climates and energy conservation. The Taft School faculty home serves as a high performance residence and learning lab for students. In US climate zone 5, it achieved a HERS 33 excluding PV and with the 13.1 kW the HERS index is -14.

Building candidate in the category

Energy & Temperate Climates

Energy & Temperate Climates

Users' Choice Award

Users' Choice Award

Green Building Solutions Awards 2016
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Author of the page

Karla Butterfield

Senior Sustainability Consultant


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