g1840g1873g1865g1854g1857g1870g1867g1858g1859g1870g1857g1857...

g1840g1873g1865g1854g1857g1870g1867g1858g1859g1870g1857g1857g1866g1868g1870g1867g1862g1857g1855g1872g1871g1875g1861g1872g1860g1864g1857g1859g1853g1864g1861g1871g1871g1873g1857g1871
g1846g1867g1872g1853g1864g1866g1873g1865g1854g1857g1870g1867g1858experiencedg1859g1870g1857g1857g1866g1868g1870g1867g1862g1857g1855g1872g1871
g3404
18
121
g1876100%g3406 15%
From the calculation of available data that represented contractors, 15 percent of
the reported green projects experienced any litigation, alternative dispute resolution,
informal resolution procedures or any other adversarial proceedings pertaining to the
green aspect of the projects.
Using the total number of green projects, architects and contractors were involved
and the total number of green projects that experienced any legal issue, confidence
intervals have been calculated as shown in Table 6.1 to estimate the chances of architects
and contractors to experience legal issues within the sample of green projects that
experience issues.
Table 6.1. 95% Confidence Interval of Architects and Contractors to Experience Legal Issues
Organization Type
Total Number of
Green Projects
Number Green
Projects with Issues
Confidence Interval
Lower Limit Upper Limit
Architects 334 44 10% 17%
Contractors 121 18 9% 21%
6.4 Projects delivery methods used in green projects with issues
Information on project delivery methods was only collected on green projects that
experienced issues. From Fig. 5.8, it can be seen that conventional Design-Bid-Build
method was most frequently encountered on green projects with issues at 39 percent. The
second most encountered project delivery method with issues was Design-Build at 32
percent. These two project delivery methods accounted for 71 percent of the green

130
projects with issues. Recently Construction Manager at Risk (CMAR) has been gaining
popularity as a project delivery method (Huang 2011) and it was encountered on nine
percent of the projects. Integrated project delivery (IPD) which is the newest of the
project delivery methods (Winstanley 2011) accounted for six percent of the projects.
6.5 Contract types used in green projects with issue
Information on contract type was only collected on green projects that experienced
issues. From Fig. 5.9, it can be seen that the guaranteed maximum price (GMP) contract
type that was used for the majority of green projects with issues at 32 percent. The lump
sum contract type was the second most preferred contracting type at 26 percent. The
remaining two contract types – unit price and cost plus seem to be almost equally
preferred for use on green projects at 21 percent and 19 percent respectively.
6.6 Confidence interval calculation of green projects to experience any legal issues
based on three different variables
Section 5.3 provides various descriptive statistics of green projects with issues, like type
of the project, type of project delivery method, and type of contract. Using this data, this
section calculates the confidence interval based on number of projects for each variable.