building an affordable net zero home...cheap out on the stuff that is easier to replace or add...
TRANSCRIPT
Part 1: A Case Study Part 2: Our Guide
Building an Affordable Net Zero Home
• Greenfield, MA • .3 acres
The Giordano – Smeltz Residence Case Study
503 kW Surplus energy generated
5144 kW Total energy generated
68o F Avg. winter-time 1st floor temp.
8203 HDD Base 68o F
Performance Oct. 2013 – Oct. 2014
Envelope
Infiltration • .54 ACH50
R Values • Walls 46 • Roof 78-96 • Foundation Wall 30 • Foundation Slab 20
Windows
• Mostly double paned • Weighted avg. U value .28
Dimensions First Floor
Systems
Photo Beth Reynolds
Heat and Ventilation
Systems
• 4.5 kW micro-inverter PV system • Drain-back solar hot water system, 80 Gallons of
storage, 4 x 10 panels
Final Cost
$145,000 + $60,000 = $205,000 • Includes $15,000 in incentives • Does not include a cost for Spartan’s labor
Construction Land Combined
www.ZeroandBeyond.com/cost
Our Guide to Affordability Big Picture Choices
• Pick an accessible site with city services • Stick with simple shapes • Single floor • Build as small as you can • Stay within code; avoid engineering
• No basement • Passive Solar – Consider those windows as
cheap solar panels • Placement of windows and doors • Frost Protected Shallow Foundation (FPSF)
Big Picture Choices
System Choices: Heat
• Avoid central heating systems and burning things
• Use air source heat pumps (AKA mini-splits, ASHP)
• Open floor plan • What about wood?
• Direct Ventilation
• Heat Recovery Ventilator (HRV)
System Choices: Ventilation
• Solar Hot Water (SHW)
• Air source hot water heat pump (ASHWHP)
• Water heat recovery
System Choices: Hot Water
goSpartanSolar.com
Cheap out on the stuff that is easier to replace or add later.
• Appliances • Trim • Cabinets
Material Choices
• Sinks • Toilets • Interior doors
• Solar PV and Hot Water • Do put in the pipes/conduit and get the right tank
Material Choices: Salvage
• Windows and doors • Foam board • Sinks, cabinets, lighting and plumbing fixtures • Avoid salvage toilets
Easily Salvaged Materials
• Trim, Interior and exterior • Siding • Roofing
Material Choices
• National database of incentives: dsireusa.org
Massachusetts • Home Energy Star certification – up to $7000 • Solar hot water – up to $4500 plus tax credits • Air source heat pumps – up to $1250 / unit • Solar Photovoltaics (PV) – Low interest loan
program plus tax credits. Safe to budget earning $1000/year for 7 years from SREC’s.
Capitalize on Incentives
Do it Yourself (DIY)
Resources • GCC – Greenfield Community College • SEON – Sustainable Outreach Network • NESEA – Northeast Sustainable Energy Assoc. • WMGC – Western Mass Green Consortium • GBA – Green Building Advisor • JLC – Journal of Light Construction Field Guides • For Pros By Pros books • ZeroandBeyond.com