Thursday, March 8, 2012

Florida Green Roofs (Dead) and Value Engineering?

Living roofs are usually one of the first components of a construction project to become 'value engineered' here in the southeastern U.S.  With an average cost of $20 per square foot for a variety of different green roof vendor projects, the dollar impact on a project can be significant.

Even with the costs, the benefits of green roofs can be many including financial.

Florida dead living roof, value engineering results

Importantly, cutting corners on a green roof system can result in serious performance issues.  The photos here are of a Florida living roof (dead now as of last week) where the client chose a landscaper who had never worked on a Florida green roof before to install plants.

Dead roofs can prevent fire hazards and tort liability issues

Unfortunately, the lowest initial cost does not mean guaranteed performance.

Moreover, lowest costs can sometimes result in highest costs over time.  Especially when the original installer does not remedy the dead plants.

The roof shown here has multiple problems.  In the present condition the dried, dead plants are a fire hazard.  One little spark from a cigar below,  carried up on a wind current could result in serious roof or building damage.

Using a landscape company who does not have roofing insurance can result in liability if a worker falls

With all the weed seed accumulated on the roof, any dormant desirable rootstock will be overwhelmed and shaded out by the noxious plant growth.

The visual failure and negative impact is prominent.  Clients and staff alike may complain about the way the dead plants appear.

THe wild weed seed source has coasted the roof and will choke out any remaining good rootstock

The cost to remove the unsatisfactory material will be much higher than the installation cost of the wrong plant types.

Finally, the client is lucky the landscaper did not have a staff member fall from the roof.  Most ground level landscape contractors are not ensured for working on roofs.  Always check not only for adequate insurance but for applicable state licenses.  In Florida, roof work should include a licensed roofer.

Value engineering sometimes has a way of biting back.  Of course, this roof is in litigation now.  Ultimately though, it will end up costing the client much more than the highest original bid.

For green roofs,  doing it right the first time is important for long term success, regardless of costs.


don Stafford said...

Don't blame poor construction on what an uninformed contractor has called Value Engineering. True Value Engineering is a formal professional process in which professionals are trained and certified(see for the professional society website) Contractors sometimes call blatant cost cutting and quality reduction value engineering, but it is not. True value engineering on this project would have assured that the functions of the green roof were maintained, whether or not there were opportunities for reduction in capital or operating costs. Please do not use this term incorrectly and ruin the reputation of a profession that you have not taken the time to research or understand.

Kevin Songer said...
This comment has been removed by the author.
Kevin Songer said...

I am sorry but registered and certified professionals can value engineer the quality out of a project. Unfortunately, cheaper doesn't always mean better. Your point is well taken though however today the general perception of value engineering is best described as only 'cost-cutting'. I am glad you and your organization are working to change that perception. Best of Luck. In the meantime I and others shall be wary of these practices.

Nuri Rossignol said...

This green roof should be replaced as soon as possible. A discarded cigarette may be enough for this to catch fire. Reputable engineers would be needed to work on this to achieve the best results. Safety should be the primary concern.