Meditch Murphey Architects

1
Designing the Zero Energy House

• Marcie Meditch - AIA
• Mike Binder Assoc. AIA, LEED-AP

2
Who We Are

• Meditch Murphey Architects is a small firm based
  in Chevy Chase, MD.
• Mostly single family homes but expanding into
  multi-family housing, small commercial and
  institutional projects.
• Commitment to sustainable design that is
  comfortable, beautiful and affordable.

3
What IS Zero-Energy?

• Goal House is designed to produce as much
  energy as it consumes on yearly basis.
• The power grid is our storage system.

4
Our Motivation
Chesapeake Zero

• To prove that a zero-energy, market-viable
  speculative house is possible.
• Cost competitive
• Beautiful
• Sustainable
• Because American energy independence is
  important.
• Because a healthy natural environment is important

Bethesda Zero
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How to achieveZero-Energy

• Highly Insulated, Tightly Sealed Envelope
• High Efficiency Mechanical System
• High-Efficiency Appliances
• Taking Advantage of Free Energy
• Solar Power Heat and Electricity

6
Beyond Zero-Energy

• Water efficiency
• Sustainable materials
• LEED-H Platinum Rating
• Leadership in Energy Environmental Design for
  Homes.
• Levels (high to low)
• Platinum
• Gold
• Silver
• Certified
• EnergyStar Home
• Public Outreach and Education
• Market Viability

7
Design Process

• Integrated Design Team
• Architect
• Owner
• Builder
• Mechanical Electrical and Plumbing Engineer (MEP)
• Structural Engineer
• Civil Engineer
• Landscape Architect
• LEED Consultant/Green-Rater
• Sustainability from Day-1
• Staying focused on goals
• Accepting trade-offs
• Energy vs. water vs. materials
• Sustainability vs. cost
• Up-front vs. recurring costs
• Exploit synergy, know when to stop

8
The Architectural Design

• Comfort
• Aesthetics
• Efficiency
• Sustainability
• Cost
• Context

First floor
Living room Dining room viewed from Kitchen
Second floor
Kitchen viewed from Dining Room
Front of house with entry and pergola.
Solar array
9
Site Selection

• Infill vs. Virgin Territory
• Public Amenities
• Transportation

1/4 mi
1/2 mi
10
Site Selection

• Infill vs. Virgin Territory
• Public Amenities
• Transportation
• Community Services

11
Site Selection

• Infill vs. Virgin Territory
• Public Amenities
• Transportation
• Community Services
• Greenspace

CLUBHOUSE
PARK
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Site Selection

• Infill vs. Virgin Territory
• Public Amenities
• Transportation
• Greenspace
• Community Services
• House Orientation for optimum solar income
• Passive solar design
• Solar hot-water and Electricity.

13
Building Demolition Construction Waste

• Neighbors offered materials from existing house
• Cabinets,
• Flooring
• Fixtures
• Windows Doors
• Contractor salvaged all usable materials for
  reuse/recycling.
• Very little waste sent to landfill.
• Framing lumber being ordered to minimize waste.
• All waste is being tracked.
• Waste materials will be sorted and recycled to
  greatest degree possible.

14
Envelope Insulation

• The cheapest energy to buy is the energy you
  dont use.
• Continuous Air-Barrier, sealed at all openings
  and edges.
• Basement walls R-20 (R-13 by code)
• Slab R-10
• Wall R-33 (R-19 by code)
• Roof R-50 (R-30 by code)
• High-reflectivity roofing to reduce heat island

15
Envelope Windows

• Windows/Doors
• U-factor 0.32 (R3)
• Solar Heat Gain Coeff. (SHGC) 0.28

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Envelope Windows

• Windows/Doors
• U-factor 0.32 (R3)
• Solar Heat Gain Coeff. (SHGC) 0.28
• Limit East and West facing Glass
• At least 50 more glass on North and South than
  on East and West.
• Shade South-facing Windows and Doors
• exclude heat in summer, admit it in winter

SOUTH
17
Envelope Windows
Limit East and West facing Glass At least 50
more glass on North and South than on East and
West.
18
Envelope Sustainable Materials

• Framing FSC if you can afford it we couldnt.
• Soy-based foam insulation
• Local or recycled gypsum
• Local, recycled, reclaimed or FSC siding.
• Reclaimed buildings
• Low VOC sealants

FOREST STEWARDSHIP COUNCIL Certified
19
Passive Mechanical Systems Natures Services

• Natural ventilation during swing months
• Operable windows
• Cross-ventilation
• Timed or Humidistat controlled fans in bathrooms.
• Awnings and trees reduce cooling requirements in
  summer.
• South orientation allows for some passive heating
  in winter.

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Active Mechanical Systems Heating Cooling

• Geothermal Ground Source Heat Pump
• Energy Recover Ventilator
• Sealed duct work, all INSIDE the Envelope.
• Mechanical Ventilation seal tight, ventilate
  right 0.35 air changes per hour.
• House zoned to allow upstairs and basement to be
  shut down when not in use. Master bedroom is
  also a separate zone for day-night differential
  control.

21
Appliances

• EnergyStar Appliances
• Refrigerator
• Convection ovens
• Induction cooktop
• Dishwasher
• Clothes Washer (no dryer is energy efficient
  consider clothesline instead)
• Compact Fluorescent (CFL) and LED Lights,
  EnergyStar Ceiling Fans.
• Gas fireplace w/ Electronic Ignition

22
Power Generation

• 9.5 kW Photovoltaic array
• Goal 100 of annual electricity needs
• 49 panels on the roof
• Two inverters in the basement
• Grid tied power grid is our storage system
• Solar Hot Water system
• Goal 85 of hot water needs
• 2 flat panel panels on roof (tubes another
  option)
• 120 gallon pre-heat tank in basement

23
Energy Balance

• Zero was our goal, but dont have to go that far
  to save money and the environment.
• High efficiency envelope, HVAC and appliances
  cuts demand to manageable level.
• Cut usage first before buying more PV panels.
• Knowing when to stop the better it is, the
  harder it is to improve.

24
Water Efficiency

• No irrigation system required. Plants are drought
  tolerant.
• Low-flow fixtures
• 1.75 gpm shower head
• 1.5 gpm lavatory faucets
• 1.1 gallon per flush toilets
• Clothes Washer Water Factor 5.5
• Recirculation pump water recirculated to tank
  until desired temperature is reached.
• Fixture-by-fixture graywater reuse had to
  delete because of county permit trouble.
• Still considering rainwater harvesting

AQUS system from AquaPro Solutions
25
Finish Materials Sustainability

• LEED Recognizes following materials as
  environmentally preferred
• FSC Certified (Forrest Stewardship Council)
• Recycled (including rubber)
• Reclaimed
• Local
• Rapidly Renewable (bamboo, linoleum)
• Low VOC (Volatile Organic Compounds).
• No urea-formaldehyde
• No exotic woods
• Durability more about how and where materials
  are installed than materials themselves.

Ray Amos New Oxford Studios
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Finish Materials on Our project

• No added urea-formaldehyde in anything
• Low VOC paints, sealants, adhesives.
• Hard-floors instead of Carpet
• FSC / reclaimed / local Hardwoods
• Engineered wood
• Linoleum
• Rubber
• Cabinets
• FSC / reclaimed / local woods
• NOT planned
• FSC framing or trim
• Window / Door framing hard to get.

27
Landscaping

• Keeping rainwater on-site
• Nearly 100 Pervious surfaces.
• Light colored surfaces to reduce heat island
  effect
• Rainwater harvesting (still being considered)
• Bioswales (not planned)
• Green Roof (planned as an OPTION)

28
Landscaping

• Shading the House (but not the panels)
• Saving potable water
• 100 Drought tolerant
• High-efficiency irrigation system (we need NO
  irrigation system)
• Native Species Only
• Protecting house
• No materials that attract termites within 2 ft.
  of house.
• Minimize site disturbance, add plantings to
  eliminate erosion.

29
Cost Advantages of Green Building

• Basically prepaying your energy bills for next 25
  years.
• Its (relatively) inflation-proof
• Its deductible
• Comfort
• Sustainable materials are healthier for you and
  your family to live with.
• Tight, energy-efficient construction is more
  comfortable to live in (when properly designed).
• Grants and Tax Rebates
• Federal
• State
• Local
• Cooperatives offer additional discounts.

http//www.dsireusa.org/
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ROI on Green Building

• One Example
• 11,900 added cost
• 1000 added mortgage payments per YEAR
• 1,900 utility savings per year
• About 900 / year ROI

Near net-zero house in Massachusetts courtesy
Steven Winters Associates
31
LEED-H

• Administered by U.S. Green Building Council
  (USGBC).
• Considered by many to be the de-facto standard
  for green home construction
• LEED-H is administered by approved network of
  Green Raters.
• Other standards exist
• EnergyStar (U.S. EPA)
• NAHB (National Association of Home Builders).
• Others?

32
LEED-H Cost trade-offs

• Bragging rights
• Marketing tool for sale / resale
• Can definitely add to cost, may save money in
  long run. Really depends.
• Point system seems odd at times
• Skewed in places same points for shoe rack as
  for all FSC framing.
• No-irrigation landscape earns less points than
  high-efficiency irrigation system.
• Tends to suppress innovation.
• Zero-energy design not rewarded.

33
LEED-H Our score

• Going for PLATINUM (102.5 points), might
  settle for GOLD.

34
Summary the Fundamentals

• Site selection
• Energy efficiency
• Water efficiency
• Sustainable materials
• Recycled
• Reclaimed
• Local
• Certified
• Demolition and construction waste management.

35
Summary

• Have to decide whats important to you. Setting
  priorities and limits.
• Synergy and Holistic design Look for
  opportunities to achieve multiple goals with one
  solution.
• Explore LEED but be open to other options too.
• You want something that you will love and which
  will enrich the community. This is why
  Architects are especially important.
• The Zero Energy House Project embodies all these
  principles and is at frontier of market-rate
  speculative house construction.

Webcam image April 13, 2009 821 AM
Making Progress
36
Shameless Plug

• For more information, visit our website at
  www.meditchmurphy.com
• If you are looking for a good and green architect
  for
• New construction
• Additions
• Renovations
• CALL Meditch Murphey Architects
• _at_ [phone].