I was recently ask by a friend to work up a cost estimate for a 24 x 30 garage. The estimate was for a high school and they wanted to determine if it was in their budget. The items I would have to price for the estimate would be, the concrete slab, building materials, carpentry labor and electrical. All of this would be done without the aid of a blueprint as that would bean unnecessary expense if it was found to be beyond their budget. Normally this is an easy thing to do, but I only had two days to get this all together.
My friend had already gotten a price for materials from one of the big box stores. This made my estimate easier and saved me a lot of time, but I still like to double check their list to make sure they did not miss anything. This materials list included:
-all the lumber to frame the walls
-plywood to sheet the walls and roof
-aluminum soffit and fascia materials
-felt paper and shingles
-a service door and an overhead door
Based on my building experience and the number of garages I have built, I was able to come up with a labor figure to build the shell. It would include building the garage using all of the materials listed above. The school would also supply some volunteer labor for the project.
Using my contacts, I called a couple of concrete contractors to give an estimate on material and labor to pour a 24 x 30 concrete slab. Without a blueprint with the specs. the village would want, their estimate would be based on what is normal and usaul building practices. This included a thickened 12" x 24" slab around the perimeter, 4 thick floor reinforced with steel mesh, a curb, the floor sloped 3" back to front, and a 5' wide apron across the front of the garage. I called two contractors and they both got back to me in a day.
The electric was a tough one to determine. I was able to get in touch with only one electrical contractor. He had a hard time nailing down a figure for his work without seeing the project site.
The things that would determine his cost were, how far would he have to trench in the electric, How far away was the main electric panel, and how much room was available in that panel for additional circuits. After much debate I came up with a figure that should be close to what it would cost.
There are other costs that should be considered. First,there should be a blueprint. This will need to be submitted to the village for approval. The cost of drawing the blueprint will need to be figured in the budget. Secondly, if the project is a go, permits will have to be pulled with the village. There may also be the cost of a dumpster for construction waste.
This is a pretty basic construction project for someone familiar with the trades. There are variables to every situation but for anyone not familiar with a project this size this is basically a road map as to what needs to be done.
For more homebuilding and remodeling tips go to: www.sawkerfs.com
Mike Merisko (C)2009