the greening of the rooftop module 7 green roofing: high performance roofs

The Greening of the Rooftop

Module 7

Green Roofing:High Performance Roofs

“A (roofing system) that delivers energy savings, environmental performance, and economic benefit substantially better than standard practice” (1)

High Performance Roofs

What is a High Performance Roof?

(1) Derived from US Department of Energy definition of a High Performance Building


What is a High Performance Roof?

• Contributes to a safe environment protected from the elements.

• Reduces energy costs & resource requirements through operating efficiencies.

• Delivers a lower life cycle cost by extending service life.

A High Performance Roof …


High Performance Roof Options

• Highly Insulated Roofs

• Highly Durable Roofs


Highly Insulated Roofs


Why Increase Roof Insulation?

Globally:

Locally:

Increased energy efficiency is the most cost effective way to significantly reduce green house gas emissions between now and 2030

Rising energy costs and local incentives make it a good economic payback almost everywhere

Greenhouse Gas ReductionThe Role of Energy Efficiency in Commercial Buildings

Source: McKinsey & Company / Business Week , March 10, 2008

…For Commercial Buildings

Energy Efficiency Savings Exceed Costs …..

• Old Performance Standard: ASHRAE 90.1-1999 “Energy Standard for Buildings”

• New Performance Standard: ASHRAE 90.1-2007 “Energy Standard for Buildings”

• Proposed High Performance Standard: ASHRAE 189.1-P “Standard

for High Performance Green Buildings”


Current Insulation Standards


Current Insulation Standards

ASHRAEClimate

Zone

1234567

Old ASHRAE 90.1 -1999

10151515152025

New ASHRAE

90.1 - 2007

15202020202530

ProposedASHRAE

189.1P

20252525253035

TypicalCity

Example

MiamiHoustonAtlanta

BaltimoreChicago

MilwaukeeMinneapolis

Minimum R-Values:Low-Slope Commercial Roof Insulation


Why High Performance?

• Base Performance Standards are Minimum Standards– Minimum needed to protect human occupants

• High Performance Standards support Reachable Goals– Roadmaps from the past to the future

• Base Performance Standards reflect Past Events– Past energy costs– Past environmental impacts

• High Performance Standards reflect Future Events– Rising energy costs– Increasing environmental impacts

Example:100,000 Square Foot Warehouse

Chicago, IL(Roof System Only – Gas Heat / Elec. Cooling)

Single-Ply Membrane

Thermal Insulation

Exposed Steel Deck


Comparing the Standards

Scenario

Old Standard(ASHRAE 90.1- 1999)

New Standard(ASHRAE 90.1 – 2007)

High Performance Std.(ASHRAE 189.P-1)

Insulation R Value

15

20

25

Total AnnualHeating / Cooling

Cost

$15,295

$13,172

$10,855

AnnualSavings

-

$2,123

$4,440

100,000 Square Foot WarehouseChicago, IL

Source: NRCA EnergyWise Roof Calculator (Roof System Only, Gas Heating / Electric Cooling)


Comparing the Standards

• NRCA EnergyWise Roof Calculator

• U.S. Department of Energy High Performance Building Initiative

• ASHRAE Standards Project Committee 189.1 (High Performance Green Buildings)


Find Out More…

http://energywise.specright.net/

http://www.eere.energy.gov/buildings/highperformance/

http://spc189.ashraepcs.org/


Highly Durable Roofs

Roofing & Durability

Looking Back to 1970

OPEC oil embargo• Quality of roofing asphalt

decreased as more gasoline was extracted from every barrel of oil

• Roofing asphalt became more brittle, less plastic

Asbestos • Traditional roofing “felts” relied on

asbestos fibers for strength

• Asbestos fibers replaced by lower strength organic (paper) fibers

Thicker insulation caused “thermal shock” as surface temperatures fluctuated by over 1500 F in a single day…

… causing roof membranes to age prematurely.





New material alternatives were introduced…

… but with a steep learning curve and some initial failures



“With the green building movement still in its infancy, the construction industry is rushing to promote ‘green’ products with all the excitement that comes with building a new market. History shows us, however, that while we must move forward with innovation and excitement, we must also take care to be responsible market stewards. Green product manufacturers should be careful to provide defendable proof that these products perform as stated.”

Kenneth Mentzer, President, North American Insulation Manufacturers Association. Building Design and Construction “White Paper on Sustainability”, 2003, p. 13.


What is Durability?

“… the ability of a (roof) or any of its components to perform its required functions in its service environment over a period of time without unforeseen cost for maintenance or repair” (1)

(1) Derived from Canadian Standards Association (CSA) Standard S478-95 (R2001) Guideline on Durability in Buildings.

Green Roof System Options


• Perform their required functions

• In their service environment

• Over an expected period of time

• Without unforeseen cost for maintenance or repair

• Provide an extended and predictable service life

• Anticipate extreme events and conditions

Designed and Managed to…

Green Roof System Options



Key Elements

• Durability Planning

• Performance Standards

• Project Commissioning

• Ongoing Management


Planning for Durability


Durability Planning

• Durability Planning combines Life Cycle Assessment with Quality Management

• Durability Planning draws on the best practices of ISO 9000 and ISO 14000


Durability Planning Steps

• Identify the Critical Durability Determinants– “Normal” Aging– Extreme Events– Human Activity

• Identify the Critical Durability Interventions– Inspection– Maintenance– Renewal– Replacement

– Access Control / Accountability

• Develop a Durability Action Plan & Timetable– Scheduling– Review– Countermeasure

Durability Determinants:

Membrane Weathering

Wind & Storm Resistance

Freeze/Thaw Resistance

Application Variability

Durability Interventions:

Increase Membrane Thickness

Fully Adhered System Attachment

Redundant Seams & Flashing

Seam Tape & High Solids Primers

Durability Planning Example:

High Performance EPDM Roof


High Performance EPDM Roof

Action Plan A:

60 Mil EPDM w/ Standard Seams

Strip-In Seams / Coat Membrane

Action Plan B:

90 Mil EPDM w/ Redundant Seams

Strip-In Seams / Coat Membrane

Year 1

Year 30 (1)

Year 35?

Year 1

Year 20 (1)

Year 25?

(1) Typical manufacturer warranty term for assembly shown

Durability Determinants:

Membrane Weathering

Wind & Storm Resistance

Freeze/Thaw Resistance

Application Variability

Durability Interventions:

Redundant Layers, Surface Coatings

High Strength Base Sheets

Redundant Layers, Increased Reinforcements

Heat-Welded Seams


High Performance Mod Bit Roof

Action Plan A:

2-Ply MB

Coat Surface

Action Plan B:

2-Ply MB w/ Coating

Re-Coat Surface

Year 1

Year 25 (1)

Year 30?

Year 1

Year 20 (1)

Year 25?

(1) Typical manufacturer warranty term for assembly shown


High Performance Mod Bit Roof

Durability Planning:

Durability & Current Green Rating Systems

• Green Globes– Up to 4 Points for “Building Durability, Adaptability and Disassembly” (Credit E.4)

• LEED® Canada Version– 1 Credit Point for “Durable Building” (Credit MR.8)


Establishing Performance Standards

“Something established by authority, custom, or general consent as a model or example.”(1)

(1) Merriam-Webster Online Dictionary


Performance Standards

Standard:

Synonyms: Criterion, Gauge, Yardstick, Touchstone


An Emerging Industry Standard

Performance Criteria for Constructed Roofing Systems

(PCCRS)

Performance Criteria for Constructed Roofing Systems (PCCRS)

Process & Structure

• A consensus-based process with public comment and multiple review• Central Council of leading industry experts

– Roofing Contractors– Roofing Manufacturers– Researchers, Consultants, Building Owners

• Criteria Development Groups (CDGs) for each major roofing system type– Built-Up Roofing (BUR) & Spray Polyurethane (SPF) CDGs established in 2004 – EPDM and PVC CDGs to start in 2008

“…to provide building owners and the roofing industry with conservative and dependable criteria for constructed roof systems that achieve cost-effective, long-term performance relative to the specific roof system type.”


Mission

The critical elements of roof system performance:

Desig

nM

aterials

Mai

ntenan

ceInstallation

Design Materials

Installation Maintenance


Focus

Highly Durable Roof Performance Standards

PCCRS: Find Out More

Performance Criteria for Constructed Roof Systems (PCCRS)

The purpose of PCCRS is to provide building owners and the roofing industry with conservative and dependable criteria for constructed roof systems that achieve cost-effective, long-term performance relative to the specific roof system type.

PCCRS is intended to provide guidance. It is not an approval or certification of individual companies' procedures, products or services, nor is it intended to supplant warranties or other representations or perceptions of roof system service life.

A council ("Council") has been established for the purpose of carrying out the administration, development and maintenance of PCCRS. The Council will appoint an

HomeCouncilCDGsArticlesDocumentsContact

Visit PCCRS at www.pccrs.net

Material StandardsValidity: Are the standards relevant to in-service performance?Reliability: Do the standards help predict failure points and times?

Design StandardsEnergy: Do the standards accurately predict energy use? Environmental: Are all key impacts considered?Hazard: Are fire, wind, hail, human, and other risks anticipated?System Integration: Are the connections and details understood?

Installation StandardsBest Practice: Do the standards incorporate industry best practice?Controls: Will the standards validate performance & remedy

exceptions?

Maintenance StandardsProactive: Do the standards anticipate needed maintenance and

repair?Controls: Do the standards require an ongoing plan and timetable?

Highly Durable Roof Performance Standards

Roof Performance Standard Checklist


Project Commissioning



(1) ASHRAE Guideline 0, The Commissioning Process

"a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria“ (1)



• An "umbrella" process for planning, delivery, verification, and managing of critical building functions.

• A quality assurance process that delivers preventive and predictive maintenance plans, tailored operating manuals, and training procedures.

• A formal review and integration of all project expectations during planning, design, construction, and occupancy phases by inspection and functional performance testing, and oversight of operator training and record documentation.

Source: The Whole Building Design Guide

Source: Whole Building Design Guide (http://www.wbdg.org/project/buildingcomm.php)


The Commissioning Process

• Establish a Commissioning Approach / Authority– Project A/E? Project CM? Independent 3 rd Party?

• Involve the Commissioning Authority in the Design – Establish Owner’s Project Requirements (OPR)

– Establish Basis of Design (BOD)

• Establish a Comprehensive Commissioning Plan– Overall Objectives & Budget– Commissioning Specs– Testing & Inspection Plan– Reporting Plan

• Document Compliance & Acceptance– Publish final compliance report: – Develop service & maintenance manuals– Establish ongoing audit schedules


Find Out More …

• The Whole Building Design Guide: Building Commissioning

• General Services Administration (GSA) On-Line Project Planning Tool

• Portland Energy Conservation, Inc. Establishing Commissioning Costs

http://www.wbdg.org/project/buildingcomm.php

http://www.projectplanningtools.org/help/homepage.aspx

http://www.peci.org/library/PECI_NewConCx1_1002.pdf

WBDGWHOLE BUILDING DESIGN GUIDE


Ongoing Management

Ongoing Management

Critical Elements

• Energy Management– Is the building continuing to meet energy efficiency objectives?

• Environmental Management– Are building impacts to the environment measured and in control?

• Hazard Management– Does the building continue to provide hazard protection as originally planned?– Is a disaster recovery plan in place, and does it address known hazards?

• Life Cycle Management– Is the building “on schedule” in terms of planned life cycle?– Have planned “durability interventions” been implemented on schedule – and have they accomplished the planned effect?

• ISO Standards– ISO 9000 Quality Management Systems– ISO 14000 Environmental Management Systems

• National Roofing Contractors Association Manuals for Inspection of ….– Built-Up and Modified Bitumen Roofing Systems– Existing Single-Ply Roofing Systems– Spray Polyurethane Foam-Based Roofing Systems– Steep-Slope Architectural Metal Panel Roof Assemblies– Low-Slope Structural Metal Panel Roof Assemblies

• Whole Building Design Guide: Facilities Operation & Maintenance

Ongoing Management

Find Out More …

WBDGWHOLE BUILDING DESIGN GUIDE


Summary & Review

• Durability Planning

• Performance Standards

• Project Commissioning

• Ongoing Management

The Key Elements of a Highly Durable Roof

the greening of the rooftop module 7 green roofing: high performance roofs

Documents

high performance roofs

high performance roof

environmental performance

old performance standard

insulated roofs slide

energy standard

durable roofs slide

new standard ashrae