Ten Projects with One Year Paybacks

Here are ten+ projects that will payback the money you put into the materials in a year or less. 

Please see the important notes at the bottom of the page!



If you think "one year payback solar" is an oxymoron, have a look below.


Insulation and Weatherizing


Caulking to reduce air infiltration

Furnace duct sealing

I like this book by Bruce Harley -- I would suggest buying it, and going through your house step-by-step using the book as a guide

More (free) insulation guides.

The payback for self-installed cellulose insulation can be  inside of a year depending on your current insulation levels, climate, and fuel.  Also helps your cooling bill.

Most houses (particularly older houses) have high infiltration rates.  A few tubes of caulking can pay big dividends.

Furnace ducts that pass through unheated areas (e.g. attics) can be awful heat wasters.  A five dollar can of duct mastic (NOT duct tape) could save a hundred dollars in fuel.

To get an idea how much you might save, try my new Insulation Cost Saving Calculator.

Air Sealing

A good air sealing guide from SouthFace.org:
Air Sealing Guide (139K pdf)

Another very good Do-It-Yourself Guide To Energy Star Home Sealing
Home Sealing Guide (1.8 MB pdf)


Good, detailed guide on sealing houses to reduce air infiltration.

From the Southface website -- other good material on this site.


Sources of Air Infiltration

 Energy Source Builder #45, June 1996,




Tells you where the cold air is coming from.  You may be surprised.


Window Treatments

Bubble Wrap Window Insulation


New Installation Instruction Sheet (8/15/06)

AND, The Card Board Shutter
Based on the popularity of this Bubble Wrap window treatment, here is a Cardboard Shutter

A really cheap and quick way to insulate windows that you don't need a clear view out of.

Added some small updates to instructions 11/13/05.
Instruction sheet added 8/15/06

Added the Card Board Shutter -->

Insulating Window Quilt -- from the Econigics site



A simple DIY scheme for making highly effective insulating window quilts.

Other Conservation Projects


Other Energy Conservation Ideas

Electric Mattress Pad


Electric mattress pads consume little energy, and can allow substantial bedroom temperature setbacks.

Full Story


Solar Space Heating Projects


This is a simple $350 thermosyphon solar heater that has no moving parts -- the cost is $2.40 per sqft.

Solar Barn/Workshop


There are several other thermosyphon solar collectors

A simple and inexpensive thermosyphon solar space heater for a garage, barn, or workshop (or for a more finished space with some changes).

This project is in the Oct/Nov 2005 issue of Home Power Magazine.

Another simple solar collector that also provides improved lighting.

Garage/Workshop Sunspace


This is a very simple an inexpensive way to turn your south facing garage/workshop into a solar heated sunspace, and use your existing rollup garage door as moveable insulation.
How does it do at -20F?

A really, really simple and cheap scheme

Very Inexpensive Solar Shop Heater,
Don R. and George Waterman




Mother Earth News article, Issue 48, Nov/Dec 1977 describes a very simple collector for heating a shop.
The cost is kept down to almost nothing by using poly film glazing and some scrounged parts.

If you can scrounge the blower from an old furnace and find some used lumber, this collector probably takes the prize for lowest cost per square foot -- about 10 cents per sqft.  The payback period where I live is well under a month!

Lots of other solar heating alternatives here:  Solar Space Heating projects


The "Black Roof" Solar Collector

This is a simple and cheap solar heating system that uses your existing roof as a solar collector.  If you have the right combination of climate and roof it might well have a one year payback.

"Black Roof" Solar Attic Heater
From "Solar Air Heating Systems", Steve Kornher and Andy Zaugg

The Black Roof Collector



This is a very inexpensive system that uses your dark colored roof as a solar collector.  The cost is very low, and it can be installed with a weekends work.  It might supply about 15% of your heating needs.  It is not for all climates. 
This extracted from the book "Solar Air Heating Systems".



Solar Sunspaces

Solar Sunspaces attached to your house can provide heat to the house as well as plant growing area.  Costs vary over a huge range (less than $1 per sqft to $90+ per sqft, but they all heat with about the same efficiency.  Sunspaces up to $3 or $4 per sqft have very short paybacks.  Greenhouse suppliers sell frame and covering kits that make construction easy. 


A simple half cylinder poly hoop sunspace against your house can provide lots of heat at a very low cost -- life of the covering is about 5 years, but its easy to replace.

Many more sunspace schemes here:  Solar Sunspace projects

Low-Cost Versatile Hoop Houses

George DeVault

Mother Earth News


Mother Earth News Article, Issue 196

Good article on building and using “hoop house” greenhouses, which provide a very low cost per sqft greenhouse.  Some construction detail.  This technique could also be used for inexpensive sunspace for generating solar heat for your house.

Sunspaces built using twinwall Polycarbonate or surplus/blemished double pane sliding glass door panels can be attractive, durable, and still offer a short payback.

Solar Rooms -- excerpts from the book Passive Solar Energy, Bruce Anderson and Malcolm Wells

To keep the cost down on your  sunroom or greenhouse, use single or double wall polycarbonate glazing, or double pane glass panels for sliding glass doors that are surplus or blemished -- check with your local glass shops.
This set of extracts from the book Passive Solar Energy covers:
+ Types of solar rooms.
+ Design guidelines for solar rooms.
+ Construction details for solar rooms.
+ Pictures of example solar rooms.
Design and Installation Guide

Sundance Design Guide

This is a good 20 page or so sunspace/greenhouse construction guide.  The Sundance website  www.sundancesupply.com has more material.


You can experiment with something like this $22 sunspace to see if the concept works for you.

Instant Sunspaces

Laren Corie



ESSN Journal, Feb, 2005

A good article by Laren Corie on how to build and experiment with inexpensive sunspaces.  The example used in the article cost a grand total of $22, and went together in a couple hours!

A free download.

Many more sunspace schemes here:  Solar Sunspace projects



Solar Water Heating

Batch solar water heaters can be built for a few hundred dollars, or less than a hundred dollars if a used hot water tank is used for the batch tank.  A "typical" family of 4 uses nearly $500 per year to electrically heat water, so these simple batch tanks can be in the one year payback area.  Natural gas users will see a somewhat longer payback (at least until the gas rates go up again).

The Integral Passive Solar Water Heater Book, David Bainbridge

Download this book

This book is out of print, and difficult to get, but David Bainbridge has agreed to make it a free download.


This is a really fine book on all aspects of designing and building a wide variety of solar batch water heaters.

The book has a great mix of how-to and engineering design information -- great for builders and experimenters.

Thanks to David, the full content of the book is available here as a free download.

Solar Energy Association of Oregon


Detailed plans and performance data for a simple batch solar water heater.



Many other Solar Water Heating Projects



Important Notes:

  1. "Your results may vary" -- payback depends on factors such as your climate, what you pay for fuel, your habits...

  2. State or federal government programs may pay some or all of the bill -- Incentive Programs

  3. You must do a solar site survey before you do ANY solar project -- there is not much point in building a solar collector that does not live in the sun!

  4. People put too much emphasis on a short simple payback period.  A project that has a simple payback of ten years still earns 10% per year, and the earnings are tax free and inflation protected.  Where are you going to find a better deal than that?  Especially one that is also good for the planet.



Rev 3/11/06