About the Project


"DER"...  Sounds like something you say when you say something unintelligent.  And so, that's how I've felt at many points in this learning process.  So what exactly is a Deep Energy Retrofit ("DER")?  Isn't "HERS" a way of saying something belongs to a female?  And what exactly is the Thousand Homes Challenge?

225 Gun Hill Street, in Milton, MA is a typical example of how a simple renovation project can spiral into something much deeper and nefarious.  And so, what began as a simple renovation of a home in Milton has become an extreme exercise of "We can do better than that!" and an adventure in navigating the bleeding edge in going GREEN on a home.  It's also a humbling lesson in construction management and in the challenging economics of making Green decisions on your home where you can get further lost in a sea of acronyms like, ROI, AFUE, DOE and the IRS.

Any major renovation is VERY BIG undertaking.  It is a balancing act of:
  1. Cost vs
  2. Desired finish level vs
  3. Time
When you are exploring the very extremes of a Green renovation, there is an additional variable:

     4.  Efficiency rating

Statistics 101 will tell you that when introducing an additional factor, the balancing equation becomes exponentially more complex, especially where cost is a consideration.  This is where I've torn my hair out countless times and where my contractors have wanted to pull my hair out.  This project would not have been possible without the help and patience of our Sponsors and the members of our Team.  With
out their help, I would still be lost in alphabet city, there would be no electricity in our home, no solar on our roof, no hot water, little insulation and little in the way of appliances in our kitchen.  Going Green makes a lot of social and economic sense.  Going Big Green is challenging, requires patience and takes a lot of research.  Here is our story and the lessons we've learned...

Pre-Construction Photos


The Purpose (Mission)

  • Radically remodel a 30-yr old Garrison-style home to achieve 50-70% energy efficiency (reduced Gas and Electric use)
  • Change behavior patterns to further reduce energy consumption (70-90% household energy use reduction)
  • Create a super-efficient home that uses little heat and electrical energy
  • Generate meaningful data on best practices that would benefit less extreme projects
  • Survive the process and avoid bankruptcy

Project Components

  • Deep Energy Retrofit Pilot through National Grid
  • Thousand Homes Challenge by ACI
  • Exterior Renovation
    • New Roof
    • New Siding
    • Replace all windows
  • Interior Gut Renovation
  • Replace all HVAC Utilities
  • Add a Heat Recovery Ventilation System
  • Add Solar Photo Voltaic Panels
  • Connect to Town sewer
  • Obtain Energy Star Home rating status

Measurable Objectives

  1. HERS rating and air infiltration
  2. Whole home energy use
  3. Home energy performance

Qu'est-ce que c'est Deep Energy Retrofit?

The term Deep Energy Retrofit can't be found in a Merriam-Webster product or an encyclopedia.  Even the Pop culture stopgap Wikipedia has a paltry two paragraphs of broad generalizations on the topic.  Dig hard enough on the internet and you'll get a few varied definitions while getting lost along the way in a sea of acronyms: NESEA, HERS, HRV, NZE, DER, R-value to name a few.  Different industry professionals have slightly different definitions.  However, take a step back and look at each word independently as a child might and the pieces make more sense than the whole:

Deep= Intense/Extreme
Energy= Conservation/Green Related
Retrofit= Done on an existing home rather than new construction

One definition I've seen is, "It is the renovation of an existing home that results in a profound reduction in energy consumption."  One of the more empirical definitions that I tend to lean towards is that of Ken Neuhauser from Building Sciences Corporation: "Deep energy retrofits are hard. They are not simple, quick or cheap. I would define them as taking an existing building and reducing its energy use by 50 percent over a new construction, code-built building. If we said 50 percent reduction over the current energy use, that would be easy. But if it's a dog, and you reduce it 50 percent, it's still a dog. We can do better than that."  Each decision step down to materials choices has become an exercise of "We can do better than that!" as well as "Can we afford that?"

The simplest analogy of what a DER is would be to think of what you'd get if you wore a Dry-Suit under an extreme polar expedition jacket.  Super insulation and air-sealing to the point that you need a mechanical ventilation system to bring fresh air into your home.

The Town of Milton

The Town of Milton, located in Norfolk County, Massachusetts, a perennial top 10 winner of Money Magazine’s “Best Places to Live” in America (#5 in 2009), noted for its close proximity to downtown Boston and strong schools (including Milton Academy), is full of historic homes, tree-lined streets, well-tended gardens, and lots of parks and playgrounds.  The Town of Milton is one of the most active environmentally-conscious towns in Massachusetts.  It is currently moving towards achieving State recognized "Green Communities" status and has a very active community energy/environmental conservation group, Sustainable Milton (local chapter of the Mass. Climate Action Network).  The town currently has a Wind Farm project underway, public conservation programs and recently voted to adopt the more efficiency-minded "Stretch" building code.

Home Description

225 Gun Hill Street is a circa 1980, two-story Garrison style home.

  • 5 Bedroom/2 Bath
  • Vinyl siding over wood shingles
  • U-G-L-Y
  • Windows with gaps large enough to pass lunch menus through
  • Inefficient Kitchen/Laundry appliances and HVAC
  • Measured air leakage: 95 sq. in. (1695 CFM @ 50 Pa)
  • Forced Hot Air Heating system
  • Central Air
  • Natural Gas fired hot water heater
  • Attic- R 19 insulation
  • Above Grade Walls
  • 3 Bedroom/3 Bath
  • Fiber-Cement Siding (JamesHardie)
  • Measured air leakage: TBD
  • Hydro-Air Heating system
  • Central Air
  • Super-Efficient Natural Gas fired hot water heater (AO Smith Vertex 100)
  • Attic- Lapolla AirTight R 52 closed cell insulation
  Pre-Construction Post-Construction
 AtticR 19 Fiberglass
8" Lapolla AirTight R 52 closed cell insulation
 Above Grade WallsR 12 FiberglassR 38 Poly-iso Rigid Foam + existing R19 Fiberglass
 Foundation Wall
R 19 FiberglassR 21 Close cell spray foam
 Basement Floor
NoneR 10 Rigid Foam
 WindowsR 2 Double Paned, double hung
R 5 (0.2 U-factor) triple-glazed casement windows
 Mechanical Ventilation (HRV)
Lifebreath Model 195ECM HRV system, integrated into warm air ducting
 Cooling 16 SEER 2.5 ton, 13.5 EER Bryant AC unit
 Heating60% efficient gas-fired forced hot air furnace
Bryant FE4A Air Handler with Hydro-air heating supported by AO Smith Vertex 100 water heater.
 Hot Water
Bradford White Defender
100,000 BTU 96% efficient AO Smith Vertex 100 Power Direct Vent

Project Description

225 Gun Hill Street is located in the center of Milton and is a Garrison-style home with approx. 1,715 sq. ft above grade.  As a part of a whole house renovation plan the home is undergoing a Deep Energy Retrofit through a pilot program run by National Grid and also participating in ACI's Thousand Homes Challenge, targeting drastic household energy use reductions through a combination of efficiencies afforded by the DER, super-efficient household appliances and lighting and behavioral changes.

Dave Legg (National Grid)- Deep Energy Retrofit program administrator
Ken Neuhauser (Building Science Corporation)
Linda Wigington (ACI)- Program Administrator for Thousand Home Challenge
Michael Castellano- Electrician
Jeff Rhodin (Sustainable Energy Analytics)- HERS Rater and Energy Star Certifier

Going for Energy Star Certification

To earn the ENERGY STAR, a home must meet strict guidelines for energy efficiency set by the U.S. Environmental Protection Agency. These homes are at least 15% more energy efficient than homes built to the 2004 International Residential Code (IRC), and include additional energy-saving features that typically make them 20–30% more efficient than standard homes.  Homes achieve this level of performance through a combination of energy–efficient improvements, including,
  • Effective Insulation Systems
  • High–Performance Windows
  • Tight Construction and Ducts
  • Efficient Heating and Cooling Equipment
  • ENERGY STAR Qualified Lighting and Appliances

To ensure that a home meets ENERGY STAR guidelines, third–party verification by a certified Home Energy Rater (or equivalent) is required.  Enter Jeff Rhodin, our HERS rater.  This Rater works closely with the builder throughout the construction process to help determine the needed energy–saving equipment and construction techniques and conduct required on–site diagnostic testing and inspections to document that the home is eligible to earn the ENERGY STAR label.

Practically speaking, passing the tests required by Energy Star should be a formality as the minimum standards of the Deep Energy Retrofit far exceed that of Energy Star.  That said, the following have been considerations that were would otherwise have been a non-issue as far as the other renovations are concerned:

  • Verification that the A/C Condenser unit was not oversized (double verification of Manual J calculations)
  • Calculation of HERS rating
  • Energy Model of home
  • Testing of ducts to verify leakage below 6 cfm
  • Thermal Bypass Inspection Checklist
  • Energy Star windows required
It's an added cost but we get a baby blue Energy Star sticker for the house at the end of the process.