Edminster-Bohner Deep Energy Retrofit

Ten years in, we're still happy with what we did, though several improvements are still on the wish list.

 

The project was driven by the confluence of several environmental goals, along with a specific problem to be solved. The principal environmental goals were to improve the home’s overall energy performance and durability; additional environmental goals were to improve daylighting and ventilation while enhancing comfort and aesthetics. The specific problem we needed to solve was a wood-framed pony wall that extended below grade, representing a long-term durability risk.

 

  • Project scope and initial goals
    • Resolve durability risks, particularly below-grade wood-framed wall.
    • Improve energy efficiency.
    • Improve thermal comfort.
    • Improve aesthetics, solar access, and relationship to the outdoors.
    • Produce energy on site (install PVs).
    • Enlarge living room.
    • Accomplish all of the above in as resource-efficient a manner as possible and using environmentally preferable materials and methods.
  • Deconstruction/Demolition– Recyclable materials (primarily wood scrap, cardboard, and metals) were source-separated and recycled. Non-recyclable waste (primarily roofing that was well past its life expectancy, and leaky single-paned windows) were landfilled. Usable wood scraps were retained for future projects. The old water heater was donated to another project.

  • Material Selection
  • Roofing: steel in sloped areas, highly durable five-ply built-up roofing under living roof in flat area
  • Interior wall finishes: low-VOC paints and earth plasters
  • Decking: FSC-certified, highly durable tropical Machiche
  • Windows: energy-efficient, durable, steel-clad wood

 

  • Indoor Environmental Quality– Low-VOC finishes used throughout. Forced air ducting removed, reducing blowing particulates. High-efficiency fans installed in baths and kitchen. 

Quick Facts

General

Location
115 Angelita Avenue
Pacifica, CA94044
United States
Building Type
Project Type
Basis of Performance Claim Verified,
Bedrooms 3
Conditioned Floor Area 1 600

Energy Summary

Energy Data Type
Renewable Energy System Type(s)
Ratings
Annual renewable energy generated

Envelope and Mechanicals

Subslab assembly
Foundation wall assembly

poured-in place concrete

Above grade wall assembly
Door Assembly

3 sets of double-paned patio doors, hinged; 2 sets wood, 1 set wood clad. 1 old single-paned half-glazed door, 1 new top-light wood entry door. Steel insulated door from house to garage.

Air Changes per hour, ACH50 8.20
SW facade 115 Angelita Exterior from NW 115 Angelita 1st floor plan 115 Angelita Foyer + living 115 Angelita Living 115 Angelita Living 115 Angelita

Project Team:

Other Team MemberTeam Member: Peter Yost

Other Team Members:

Ann Edminster, Design AVEnues LLC -- owner/designer
John Fordice, Other Fish Architect -- architect of record
Bill Dakin, Davis Energy Group -- ME/HVAC designer
Bill Wilson -- living roof designer

Ratings:

Awards:

Sustainable San Mateo County Green Building Award

Completion

Completion Date: Saturday, October 1, 2005

Scope

Renovation of various parts/aspects of existing ~1,400 sf home plus 2005 addition of ~200 sf.

Type of Construction Part of Building,
Number of buildings
Floor area of each building
Bedrooms 3
Stories 2
Conditioned Building Volume
Conditioned Floor Area 1 600

Location and Climate Details

Address
115 Angelita Avenue
Pacifica, CA94044
United States
Location Type Suburaban
Climate Region Zone 3
Köppen Climate Type Csb
Lat. / Long. POINT (-122.476548 37.613796)
Elevation
Solar Insolation 7 kWh/m2/day
Annual CDD and Base Temp 125 | 65 deg F
Annual HDD and Base Temp 2941 | 65 deg F

Site

Site Conditions:

previously developed land, preexisting structure(s),

Site Description:

Hillside site on uphill side of street; west-facing. High corner @ NE, low corner @ SW, steep in those two corners, terraced throughout.

Monthly Energy Data and Utilities

Energy Data Type: Verified,

Electric Utility: Pacific Gas & Electric

Gas Utility: Pacific Gas & Electric

Renewables and Energy Balance

Renewable Energy Sources:Renewable energy is generated within the building footprint (e.g. solar PV on the roof),

Renewable Energy System Description & Details:

Annual renewable energy generated
Annual Renewable Energy Generated Data Type
Power Rating
Renewable Energy System Type(s)
Source of Annual Production Data

Walls and Roof

2nd floor roof: 2x10 @ 16" o.c., fiberglass batt insulation; composition shingles
2nd floor walls: 2x4 @ 16" o.c., fiberglass batt insulation
1st floor roof: attic, R-40 loose-fill wool insulation; ~60% standing-seam steel roofing, ~40% living roof over 5-ply built-up roofing
1st floor walls: ~90% 2x4 @ 16" o.c., rigid polyiso in cavities (~R-21); ~10% 2x4 @ 16" o.c., fiberglass batts

Subslab assembly
Subslab R-value
Slab edge assembly
Slab edge R-value
Foundation wall assembly

poured-in place concrete

Foundation wall R-value
Above grade wall assembly
Above grade wall R-value
Cathedral ceiling assembly
Cathedral ceiling R-value

Windows and Doors

Window Assembly:

Mostly Pozzi/Jeld-Wen wood (upstairs) and wood clad (downstairs) double-hung, double-paned.

Door Assembly:

3 sets of double-paned patio doors, hinged; 2 sets wood, 1 set wood clad. 1 old single-paned half-glazed door, 1 new top-light wood entry door. Steel insulated door from house to garage.

Average window U-factor
Door U-Factor
Door Area

Mechanical Systems

Space cooling - Manufacturer & Model
Space heating - Manufacturer & Model Munchkin,
Domestic hot water - Manufacturer & Model Munchkin
Domestic hot water - capacity
Ventilation - Manufacturer & Model Panasonic,
Lighting Manufacturer and Model
Lighting Efficiency
Mechanical Equipment Installation Details and Comments

Only spot-exhaust ventilation in baths

Envelope

Air Changes per hour, ACH50 8.20
Air Changes per hour, CFM50

General Process

Design for Adaptability:

Software Tools

Software Tools:

General modeling information:

Lessons Learned

Outcome of Project Goals:

Comfort much improved; energy performance significantly improved, albeit not dramatically. Considering the addition of floor area and not doing anything to the upstairs, we're very happy with the outcomes reflected here. We haven't yet collected energy data from the recent addition of insulation in the 1st floor attic or improvements to infiltration, expect to see more reductions from that work. Working with an existing older home that has been remodeled in stages poses significant challenges. Things I've learned in the 10 years since the bulk of the work was done would change my approach somewhat if I were to tackle the project today. For example, I would work harder on airtightness (if not going crazy with it), and I would pay more attention to window U and SHGC.

Discrepancies:

We didn't base the work on modeling, just on what we knew needed to be done. No predictions were made.

Rebates and Financial Incentives

Federal incentives
Local incentives
State incentives
Utility incentives
Other incentives
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