Building an Affordable Net Zero Home...Cheap out on the stuff that is easier to replace or add...

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