Most home building construction projects are estimated based on the prevailing cost of materials and the hourly wage to repair, install, or construct the project. Most contractors know their crews’ production rates and can estimate with accuracy.However, some conditions that affect building costs are out of the contractor’s control. Material prices, for instance, rise and fall in accordance with the nationwide or worldwide supply and demand of lumber, cement, and raw materials. Production will also change with jobsite conditions, which can change by the hour (in the case of bad weather) or by the job (if there’s a shortage of materials, or if part of the work must be done from scaffolding or ladders).
Working conditions have a major effect on labor. If you’re lucky enough to be working with highly-experienced tradesmen on a perfect jobsite in ideal weather conditions, you should have an easier time estimating labor costs. But if the weather is constantly changing, new workers are being added to your crew, or if you have to match materials to what’s already installed, your crew isn’t going to perform at their usual rate. Before you estimate the cost of labor on your next home building project, look over this list to see if any of the conditions shown could affect your labor output.
1. Hot or Cold Temperatures: Add 10 to 15 percent to labor when working temperatures are above 95 degrees or below 40 degrees F. People just can’t work as efficiently in extreme temperatures.
2. Confined Work Spaces: Add 15 to 25 percent to labor when work needs to be performed using ladders, scaffolding, or in a crawl space.
3. Height Factor: Add 1 percent for each 10 feet of height that material must be lifted above ground level.
4. Tradesmen Skill Level: Add 5 to 40 percent for tradesmen with below-average skills.
5. Small Jobs: Add 30 to 50 percent to small jobs where fitting and matching of materials is required, adjacent surfaces have to be protected, and the jobsite is occupied during construction.
6. Major Disaster Work: Add 25 to 50 percent for work done following a major flood, fire, earthquake, tornado, or hurricane. Skilled labor may be in short supply and you’ll have to settle for whatever’s available – and pay more for it too.
7. Difficult Conditions: Add 10 to 35 percent for demanding specs, rigid inspections, a demanding owner or an inexperienced architect.
While estimating construction work is a difficult skill, identifying workplace conditions can help you in determining a realistic labor cost of a job. Never make your estimate solely from the plans. Always visit the jobsite to determine actual conditions.
For other varibles that affect the cost of construction look through the practical estimating guides available at http://www.craftsman-book.com/ .
