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Calculators for Green Roof Construction

on October 7, 2010 at 1:36 pm under

Two Valuable Calculators Available for Planning:

Water Runoff Calculator and Green Roof Blocks Materials Estimator

Excerpts from  Green Roof Construction and Maintenance,  by Kelly Luckett, 2009, published by McGraw-Hill’s GreenSource Books

Hi Green Roof Fans,

As one of the contributing editors here on – you may know me as “The Green Roof Guy” – I’m starting a series of excerpts from my book Green Roof Construction and Maintenance.   As President of Green Roof Blocks, I’ve been involved in the industry since 1980, am a LEED Accredited Professional, and a Green Roof Professional (GRP).   Here we go:

Stormwater Runoff
Discussions of storm water runoff are typically concerned with the impervious surfaces within a certain development or a certain watershed.   Many municipal planning and zoning authorities have implemented policies restricting the amount of storm water runoff a new or existing development is allowed to generate. Some mandate no increase in the pre-development runoff volumes for new projects under consideration for building permits.

To help further promote green roof projects in the United States, we decided to make  our Water Runoff Calculator tool available free of charge.   The Excel based spreadsheet is available for download from the “Downloads and Calculators” page of the Green Roof Blocks website.

This storm water management tool quantifies storm water management values. Storm water runoff coefficients speak to the rate and volume at which water percolates into the ground rather than running over the ground’s surface. Where the surface of an undisturbed forest floor allows water to quickly be absorbed into the ground, a concrete or asphalt parking lot would instead repel water across the surface to lower neighboring grades. The difference in the permeability of the surface is sometimes referred to as imperviousness of the surface.

Green Roof Blocks Materials
Estimating materials well in advance of a project can be a challenge. Always contact the product providers for assistance and specifics. For example, we developed an easy tool to  help our clients using Green Roof Blocks and Green Paks- the Green Roof Materials Estimator, which is also  available at the “Downloads and Calculators” page of  our website. Assumptions in this Excel spreadsheet allow you to put in an advance date and receive an accurate estimate for your proposal based on that future time frame. Use this calculator to build multiple options based on your budget to present to your client. For questions, please contact us and we will be happy to customize a solution for your project.

Make sure to read my column, and to learn more about my company,  visit my website at:  or send me an email to:

Kelly Luckett, A/K/A The Green Roof Guy