When construction is very actively growing, total construction costs typically increase more rapidly than the net cost of labor and materials. In active markets overhead and profit margins increase in response to increased demand. These costs are captured only in Selling Price, or final cost indices.
General construction cost indices and Input price indices that don’t track whole building final cost do not capture the full cost of construction projects. To properly adjust the cost of construction over time you must use actual final cost or selling price indices.
Producer Price Index (PPI) Material Inputs (excluding labor) costs to all construction are up +4.2% in 2017. More specific input costs, nonresidential structures in 2017 are up 4.3%, infrastructure cost are up over 5% and single-family residential inputs are up 4.3%. But material inputs accounts for only a portion of the final cost of constructed buildings.
Labor input is currently experiencing cost increases. When there is a shortage of labor, contractors may pay a premium to keep their workers. Unemployment in construction is the lowest on record. A tight labor market will keep labor costs climbing at the fastest rate in years.
ENRBCI and ENRCCI are prefect examples of commonly used indices that DO NOT represent whole building costs, yet are widely used to adjust project costs. An estimator can get into trouble adjusting project costs if not using appropriate indices.
CPI, the Consumer Price Index, tracks changes in the prices paid by urban consumers for a representative basket of goods and services, including food, transportation, medical care, apparel, recreation, housing. This index in not related at all to construction and should never be used to adjust construction pricing. Historically, Construction Inflation is about double the CPI. However for the last 5 years it averages 3x the CPI.
Inflation can have a dramatic impact on the accuracy of a construction budget. Usually budgets are prepared from known current costs. If a budget is being developed for a project whose midpoint of construction is two years in the future, you must carry an appropriate inflation factor to represent the expected cost of the building at that time.
Taking into account the current (Jan 2018 12 mo) CPI of 2% and the most recent 5 years ratio of Construction Inflation to CPI, along with accelerated cost increases in labor and material inputs and the high level of activity in construction markets, I would consider the following forecasts for 2018 inflation as minimums with potential to see higher rates than forecast.
Residential construction saw a slowdown in inflation to only +3.5% in 2015. However, the average inflation for five years from 2013 to 2017 is 5.8%. It peaked at 8% in 2013. It climbed back over 5% for 2016 and reached 5.8% in 2017.
Anticipate residential construction inflation for 2018 at least 5%.
Several indices for Nonresidential Buildings have averaged 4% to 4.5% over the last five years and all have reached over 5% in the last three years. Nonresidential buildings inflation totaled 18% in the last four years. My forecast shows nonresidential buildings spending in 2018 will reach the fastest rate of growth in three years, which historically leads to accelerated inflation.
Anticipate construction inflation for nonresidential buildings during the next two years near a growth rate of 5% rather than the long-term average of 3.5%.
Non-building infrastructure indices are so unique to the type of work that individual specific infrastructure indices must be used to adjust cost of work. The FHWA highway index increased 17% from 2010 to 2014, dropped 2% in 2015-2016, then increased 2% in 2017. Inflation for refineries and petrochemical facilities has dropped 5% in the last 4 years. Input costs to infrastructure are down slightly from the post-recession highs, but most costs have increased in the last year. Input cost to Highways are up 4.7% and to the Power sector are up 5.8% in 2017. Work in Transportation and Pipeline projects is increasing rapidly in 2017 and 2018. Expect inputs in these markets to show large increases in 2018.
Infrastructure indices registered 2% to 4% gains in 2017. Anticipate a minimum of 3% to 4% inflation for 2018 with the potential to go higher in rapidly expanding markets.
- Long term construction cost inflation is normally about double consumer price inflation (CPI).
- Since 1993 but taking out 2 worst years of recession (-8% to -10% total for 2009-2010), the 20-year average inflation is 4.2%.
- Average long term (30 years) construction cost inflation is 3.5% even with any/all recession years included.
- In times of rapid construction spending growth, construction inflation averages about 8%.
- Nonresidential buildings inflation has average 3.7% since the recession bottom in 2011. It has averaged 4.2% for the last 4 years.
- Residential buildings inflation reached a post recession high of 8.0% in 2013 but dropped to 3.4% in 2015. It has averaged 5.8% for the last 5 years.
- Although inflation is affected by labor and material costs, a large part of the change in inflation is due to change in contractors/suppliers margins.
- When construction volume increases rapidly, margins increase rapidly.
- Construction inflation can be very different from one major sector to the other and can vary from one market to another. It can even vary considerably from one material to another.
The two links below point to comprehensive coverage of the topic inflation and are recommended reading.