Skip to main content

- What is Passive Building?
  Your passive building questions, answered
  
  Passive Building
  
  Passive Building Principles
  
  Passive Building FAQs
  
  A Better Way to Zero
  
  Passive Building Foundations Training
- Sectors
  Passive isn't just for houses
  
  Single-Family
  
  Multifamily
  
  Office Buildings
  
  Schools
  
  Other Non-Residential
- Projects
  Phius Certified Projects are the most energy efficient and comfortable buildings in the world
  Find a Project
  
  Project Certification
  
  Submit a Project
  
  Certification Review Queue
- Products
  Phius Certified Products are guaranteed to perform to passive standards
  View Products
  
  Product Certification Overview
  
  Window Certification
  
  Panel Certification
- Professionals
  Phius Certified Professionals are on the cutting edge of high-performance building
  Find a Professional
  
  Phius Certified Consultant (CPHC®)
  
  Phius Certified Builder (CPHB)
  
  Phius Certified Rater
  
  Phius Certified Verifier
  
  Phius Certified Trades Professional
  
  Phius Associate
  
  Maintain Credentials
Our Approach
- New Construction
  Phius CORE and Phius ZERO provide the path for constructing a Phius building from the ground up.
- Retrofit
  Upgrade existing buildings to Phius standards using Phius CORE REVIVE and Phius ZERO REVIVE.
- Commercial
  Phius standards aren't just for residential buildings. Phius CORE COMM and Phius ZERO COMM can be applied to any non-residential building.
Categories
December 1 – January 16

Phius Certified Trades Professional - Enclosure Specialist Training | December 2025 & January 2026 | Portland, OR
Become a Phius Enclosure Specialist!
Upcoming Sessions
- Jan. Webinar: Walking Through METr
  January 13
- Phius Certified Builder Training and Certification Exam | January 2026
  January 20 – 30
- Phius Certified Consultant Training & Certification Exam | January 2026
  January 20 – 30
- Member Office Hours - METr
  January 20
- Policy Work
  Promoting policies designed to grow passive building
  Policy Database
  
  Financial Incentives
  
  Codes
  
  Qualified Allocation Plans
  
  Cost Data
- Tools and Support
  Providing the tools you need to create healthier buildings
  Resource Library
  
  Certification Support
  
  Calculators and Protocols
  
  Feasibility Study
  
  METr Design Tool
  
  WUFI Passive Design Tool
  
  Climate Data
  
  Quality Assurance
  
  Tech Corner

Project 1810

25 Dukes Rd

Sandcastle Construction

Nantucket, Massachusetts

Building Function

Single-Family
Project Type

New Construction
ASHRAE Climate Zone

5A - Cool - Humid
Construction Completion

2020
Status

Certified
INT. Conditioned Floor Area

3950 ft²

Core Project Team

Phius Certified Rater

Andy Buccino
Phius CPHC (Secondary)

Hans Breaux
Phius CPHC (Lead)

Ian Johnson
Project Submitter

Rebecca O'Hearn

Project Information

- Architecture Planning
  
  Sandcastle Construction
- Building Owner
  
  Chuck Lenhart
- Mechanical Systems Designer
  
  ACK Air Duct LLC
- Construction Company
  
  Sandcastle Construction
- Building Function
  
  Single-Family
- Project Type
  
  New Construction
- Construction Type
  
  Wood Frame
- Number of Units
  
  1
- Number of Stories
  
  3
- Program Version
  
  PHIUS+ 2018 Source Zero
- All Electric
  
  Yes
- INT. Conditioned Floor Area
  
  3950 ft²
- Status
  
  Certified
- Design Certification
  
  January 3, 2022
- Final Certification
  
  November 11, 2024
- Construction Completion
  
  2020
- ASHRAE Climate Zone
  
  5A - Cool - Humid
- Region
  
  Northeast

Performance

- Annual Heating Demand
  
  4.74 kBTU/ft².yr
- Annual Cooling Demand
  
  1.64 kBTU/ft².yr
- Peak Heating Load
  
  3.39 kBTU/ft².yr
- Peak Cooling Load
  
  0.32 kBTU/ft².yr
- Site Energy Use Index (EUI)
  
  10.88 kBTU/ft².yr
- Site Energy Use Index (w/Renewables)
  
  -0.2 kBTU/ft².yr
- Compliance Software
  
  WUFI Passive
- Source Energy (Residential)
  
  7051 kWh/person.yr
- HERS Rating
  
  30
- HERS Rating w/Renewables
  
  -8
- Air Tightness (per enclosure area)
  
  0.024 CFM50/ft²

Enclosure

- Window Manufacturer 1
  
  Anderson

Systems & Equipment

- Ventilation System Manufacturer
  
  Zehnder
- Measured Ventilation Fan Efficiency
  
  0.3 W/cfm
- Heating System Manufacturer
  
  Mitsubishi
- Cooling System Manufacturer
  
  Mitsubishi
- Hot Water System Manufacturer
  
  Sanco
- Renewable Energy Type(s)
  
  On-Site PV
- Renewable Energy Annual Production
  
  12819 kWh/yr
- Renewable Energy System Size
  
  9.62kW