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.
The cost to build a garage ranges from $3000-$50,000. The cost to build a garage varies greatly depending on location, if homeowners build the garage themselves or hire someone to do it and if the garage is small or large, simple or deluxe. The average cost of building a garage when a contractor is used is $35-$45 per square foot.