DIY Project Guides
Answers to common home and garden questions, with the numbers worked out and the sources listed. Each guide links to the calculator that does the math for your own home.
What a Space Heater Costs to Run, by State
Every plug-in space heater turns the same electricity into the same amount of heat, so what it costs depends almost entirely on your electricity price, and that price is 3.7 times as high in Hawaii as in North Dakota.
What Size AC or Heat Pump Do I Need?
For a window or portable unit, ENERGY STAR publishes a simple chart by room size.
How to Find Your Roof Pitch
Roofers and the building code describe a roof's steepness as "6 in 12" or "6/12", the inches it rises per 12 inches of run.
How Much Paint Do I Need for a Room?
Paint cans and data sheets list how far a gallon spreads, and most rooms need two coats.
How Much Gravel Do I Need for a Driveway?
A gravel driveway is mostly arithmetic once you know how deep to build it and how much the stone packs down.
How Much Mulch Do I Need?
A common mulch mistake is using too much: University of Illinois Extension calls overmulching among the most common causes of tree decline.
What Size Water Heater Do I Need?
The number on the side of a tank, 40 or 50 gallons, is not the best way to choose a water heater.
Tank vs Tankless Water Heater Sizing
Tank and tankless water heaters are sized in different units, which makes them hard to compare in a store.
First Frost Dates by City
Here are the average first fall frost dates (32°F) for 143 cities in 47 states, from NOAA's 1991–2020 climate normals, plus the date by which 1 year in 10 has already had a frost..
Deck Railing Height and Baluster Spacing: The Code Rules
Building inspectors check deck railings closely, because a railing that fails can mean a serious fall.
Stair Rise and Run: The Code Rules
Inspectors measure risers and treads with a tape, and a step that is too tall or uneven fails.
How Much Attic Ventilation Do I Need?
Attic vents are sized by a simple rule in the building code, but the numbers on vent packages and the "1/300" exception confuse a lot of people.
How to Prevent Ice Dams
An ice dam is a ridge of ice at the edge of the roof that traps melting snow behind it, until the water finds its way under the shingles and into the house.
Heating Oil and Propane Prices by State
EIA surveys heating oil and propane dealers every week through the heating season.
What Climate Zone Am I In, and How Much Attic Insulation Do I Need?
The energy code divides the US into eight climate zones, assigned county by county, and the insulation it asks for follows the zone.
How Much Wood Is in a Cord?
Firewood is sold by the cord, but "face cord", "rick" and "truckload" get used too, and they are not the same amount.
How Much Firewood Do I Need for Winter?
How much wood you burn depends on your climate, your house, your stove and the wood itself.
How Many Bags of Concrete Are in a Yard?
A cubic yard is 27 cubic feet, and each bag of premixed concrete makes a known fraction of a cubic foot.
Cubic Yards to Tons for Gravel, Sand, Topsoil and Mulch
Some landscape suppliers price by the cubic yard and some by the ton, so you may need to convert.
How Deep Do Footings Need to Be?
Two rules in the International Residential Code set how deep a footing goes: a 12 inch minimum and your local frost line.
5 or 6 Inch Gutters: How to Choose
A 5 inch gutter is enough for a typical roof section in much of the country.
How Much Does Snow Weigh on a Roof?
The same foot of snow can weigh seven times as much when it is wet as when it is light and fluffy.
Heating Oil vs Gas vs Heat Pump: What Heat Costs This Winter
Heating oil costs far more going into this winter than it did a year ago, and the cheapest way to heat depends on your local prices.