Cows emit a massive amount of methane through belching, with a lesser amount through flatulence. Statistics vary regarding how much methane the average dairy cow expels. Some experts say 100 liters to 200 liters a day (or about 26 gallons to about 53 gallons), while others say it's up to 500 liters (about 132 gallons) a day.
1 According to author Stu Silverman the average cost of adding a garage begins at roughly $7,500, and for a two-car garage the average costs will go much higher.2  This sort of structure will average at $27,040. 3  The resale value of this update would hold at $21,635, or a nearly 81% return on investment.or the garage addition, the typical costs include: 1  According to author Stu Silverman the average cost of adding a garage begins at roughly $7,500, and for a two-car garage the average costs will go much higher. 2  The above figures place the garage addition at $40 per square foo t.
Plus, if you plan on generating any kind of return on investment, you have to be willing and able to first make that initial investment. So before you start building, the real question you should be asking is: how much does it cost to build a garage? Give Me the Numbers According to HomeAdvisor, the national average cost of building a garage is about $25,000, though the price can range anywhere from as little as $6,000 to more than $50,000.