Difference between Linear and Non-linear Dynamic analysis

Concerning the difference between Linear Dynamic Analysis, which was understandably Response Spectrum Analysis (RSA) and Non-linear Dynamic analysis, which was on the other hand, is understood to be Non-linear Time History Analysis (NL-THA). RSA and THA are like chalk and cheese. The linear procedure that corresponds to NL-THA is obviously the Linear Time History Analysis (Lin.THA). Then which non-linear procedure corresponds to RSA? This is what made me try to resolve by posting this thread. I’m just putting forward what I think I know. Please post your opinions, if opposing, freely. 

In general, the methods of seismic analysis can be classified as (1) Static and (2) Dynamic. Dynamic analysis can further be classified as (i) Dynamic Characteristics based (static) Analysis and (ii) Time Domain Analysis. All of the above categories have their (a) Linear and (b) Non-linear counterparts. 

1) Static Analysis 

a) Linear

• Seismic Coefficient Method (SCM)(IS:1893, Cl.7.5.3 & 7.7.1): Here the seismic base shear for the building is determined by using an empharically determined time period, and distributed over the stories as lateral load proportional to an assumed mode shape, which is parabolic (but interestingly with 100% mass participation assumed). Here lateral load determination is all formula based, no modal analysis is required, and the method is therefore STATIC.

b) Non-linear: This is done by running a non-linear analysis on a non-linear building model. Non-linearity is incorporated in the analysis model in form of non-linear hinges inserted into an otherwise linear elastic model which one generates using a common analysis-design software package.

• Non-linear Static Analysis (NSP) or Pushover Analysis (FEMA-356, Sec.3.3.3; ATC-40, Ch.. Unlike as SCM (where the lateral load of a calculated intensity is applied in whole - in one shot), in NSP, analysis model is gently 'pushed over' by a monotonically increasing lateral load applied in steps up to a predetermined value or state. Here also seismic base shear for the building is distributed over the stories as lateral load proportional to an assumed mode shape, which is either uniform (FEMA-356, Sec.3.3.3.2.3-2.1) or a power distribution (FEMA-356, Sec.3.3.2.3-1.1) with the value of k* determined to be a value between 1 (inverted triangular distribution) and 2 (parabolic distribution) by an empharical method. You know why it is the method is ‘therefore’ STATIC.

*(k is the power of h shown with k=2 in the formula under IS:1893, Cl.7.7.1)

2) Dynamic Analysis 

a) Linear

i) Dynamic Characteristics based (static) Analysis

• Response Spectrum Analysis (RSA) (IS:1893, 7.8.4) – Here a DYNAMIC (modal) analysis is done to get the dynamic characteristics of the building (natural frequencies and mode shapes) from which the lateral loads corresponding to each mode shape is calculated, with which a STATIC analysis is performed for each mode, the results (BM, SF, etc.) of which are then combined (SRSS) to get the design forces.

ii) Time Domain Analysis

• Linear Time History Analysis (Lin.THA). (IS:1893, Cl.7.8.3): In THA, the support points of the model is oscillated back and forth in accordance to a recoded ground motion of an actually occurred earthquake (as recorded by a seismograph, and available in tabular form of time vs. acceleration). The results (BM, SF, etc.) are usually taken as the maximum enveloped over time (ie., the max. BM on the mid span of a particular beam in the maximum among all the BMs, each corresponding to each time point over the duration of earthquake).

b) Non-linear : As said above, this is done by running a non-linear analysis on a non-linear building model.

i) Dynamic Characteristics based (static) Analysis

• Non-linear Static Analysis (NSP) or the same Pushover Analysis mentioned above, but with the 1st mode proportionate lateral loads (FEMA 356, Sec.3.3.3.2.3-1.2) or more rightly, a combination (SRSS) proportionate lateral loads (FEMA 356, Sec.3.3.3.2.3-1.3). Please note that unlike the RSA, it’s not the results corresponding to each mode shape that is SRSS’ed, but the loads themselves. [Of course, methods have been developed and papers published on how to SRSS the pushover results corresponding to each mode shape, but not yet been standardized (by agencies like FEMA, ATC or ASCE)].

No one considers putting this version of pushover analysis under Non-linear Dynamic Analysis (and as the non-linear counterpart of RSA), but this is my starting point and the reason for posting this classification in the first place.

ii) Time Domain Analysis

• Non-linear Time History Analysis (NL-THA). (FEMA356, Sec.3.3.4.2.3). This is same as the Lin.THA, but here since the structure has non-linear hinges inserted, the members can undergo and stiffness degradation, strength deterioration – in general, damage, as a real building would, during the progress of an earthquake.

Author from SEFI
Rahul Leslie 
rahul.leslie@gmail.com

२ सय किलो तौलको जुत्ता, जसले ढाड दुखेको निको पार्छ !!!!

ढाड दुखेको समस्या समाधानका लागि चिकित्सा बिज्ञानमा अनेक उपाय छन् । तर, एक चिनियाँ मजदुरले ढाड दुखेको बिमान निको पार्न अनौठो तरिका अपनाएका छन् ।

५२ वर्षीय झाङ फोक्सिङ कारखानामा काम गर्ने मजदुर हुन् । दुखाई कम गर्न उनी पछिल्लो ७ वर्षदेखि फलामको जुत्ता लगाएर हिडिरहेका छन् । उनले क्रमशः आफ्नो जुत्तामा रहेको फलामको तौल समेत बढाउँदै लगेका छन् । यो जुत्ता लगाएर हरेक दिन १५ मिटर हिड्दा दुखाइ कम हुने उनको दावी छ ।

हाल उनी २ सय किलोभन्दा बढी तौल भएको जुत्ता लगाउँछन् र लगातार तौल बढाई रहेका पनि छन् । झाङ भन्छन–‘चार सय किलोको जुत्ता लगाएर हिड्न सकेको दिन म निकै खुसी हुनेछु ।’ अहिले उनी २ किलोमा ५० किलो फलाम थप्ने योजनामा छन् ।

यति ठूलो तौल भएको जुत्ता लगाउन कहाँबाट बल आउँछ भन्ने धेरैलाई लाग्छ । तर, उनी भन्छन्–यसरी हिड्न मांसपेशीहरु बलियो हुनुपर्दैन । शरीरको भित्रैबाट शक्ति आउँछ । जब तपाई आफ्नो मनैबाट हिड्नुहुन्छ, यो सम्भव हुन्छ ।’ उनले आफुलाई चीनमा सवैभन्दा बढि तौल भएको जुत्ता लगाउने ब्यक्तिका रुपमा दावी गरिरहेका छन् । तर, चीनको अन्य भागमा पनि यस्तै जुत्ता लगाएर रेकर्ड राख्ने अभियान चलेकाले निष्र्कषमा पुग्न भने समय लाग्ने उनी बताउँछन् ।

 

China’s Moon Landing: Was It Worth It?

China’s moon landing was a technological triumph and a cause for much chest-thumping back on the Chinese portion of earth. But some critics wondered if the vast spending was worth the money.

The Chinese moon lander, Chang’e-3, set down on the moon’s surface Saturday eveningseparated from the lander and started to look around. Yutu left a “deep trace on the loose lunar soil,” said Xinhua, China’s state-owned news agency. The rover is set to survey the moon’s so-called Bay of Rainbows over the next three months.

China is just the third country to land on the moon, following the U.S. and the former Soviet Union, which both accomplished the task decades ago. “It is an achievement deserving of respect,” said John Logsdon, a professor emeritus at George Washington University who has long tracked space policy. “Chang’e-3 is impressive as the first landing on the moon in almost four decades, landing in a place that has not been explored (and using) relatively advanced scientific instrumentation.”

As with all space extravaganzas, no matter the country, the Chinese moon project was also a way to rally public support for national missions—so-called soft power. A Xinhua commentary on the mission cited President Xi Jinping’s slogan for Chinese renewal, saying that “the dream for lunar exploration once again lights up the China Dream.”

A photo of the Yutu moon rover taken by the camera on the Chang’e-3 moon lander.

 

Zuma Press

The name of the rover was selected following an online poll of several million votes from people “around the world,” Xinhua said. In Chinese mythology, Yutu was the white pet rabbit of the lunar goddess Chang’e.

On Weibo, China’s popular microblogging site, comments were mostly positive, with some tinged with a bit of regret.

“Although the moon landing could not solve social issues,” wrote a Wuhan university professor, “our countrymen deserve to feel proud at every advancement.”

Another commenter was bit more sarcastic. “As a Chinese, I am proud! We have money to burn!” a microblogger called Caribbean Wind wrote. “But once I think that our pension fund is not sufficient and retirement is delayed to 65 years old, I cannot feel proud anymore.”

On the other side of the Pacific, space expert Scott Pace, director of George Washington University’s Space Policy Institute, said the mission indicated some “impressive” capabilities on the part of China. Pulling off a “soft landing” requires “skill in guidance, navigation and control” beyond what’s needed for an orbital mission.

China also showed it is able to lift a heavy load into space. While the Chinese rockets aren’t Apollo-sized, Mr. Pace said, “They’ve made a major down payment” toward a manned lunar landing. Chinese officials have previously said they want to land astronauts on the moon.

To former U.S. National Aeronautics and Space Administration historian Alex Roland, there is a certain been-there, done-that feeling about the Chinese lunar program. He says he expects to see two developments eventually with China’s space program.

First, “they will suffer some embarrassing failure—hopefully with an automated spacecraft,” says Mr. Roland, who now teaches at Duke University. “This may well lead them to rethink space spectaculars as public relations.”

Second, “I expect that they will discover, as we have, that space spectacular—especially manned spectaculars—are expensive, risky and hollow.” At that point, he said,  they may start to look at space launches, more for their commercial potential than their glory.

UN outlines plans for 2015 global disaster risk reduction deal

The UN hopes to seal a global agreement on reducing the risks from extreme weather events, earthquakes and tsunamis at a 2015 summit in the Japanese city of Sendai.

The new deal – set to be brokered by the UN’s office for disaster risk reduction (UNISDR) – is likely to focus heavily on climate change adaptation and resilience.

A successful outcome from the March summit could lay the foundations for separate talks on a UN emissions reduction treaty, scheduled for Paris in December that year.

Over 8000 delegates including ministers and heads of state will attend the Sendai meeting. UNISDR chief Margareta Wahlström says it will be a “rare opportunity to forge universal agreement on how to build disaster resilience across all sectors of society”.

In 2005 168 countries including the US, China and EU member states signed the Hyogo Framework, adopting a set of commitments to reduce vulnerabilities to natural hazards.

These include developing public awareness strategies, investing in early warning systems and building ‘resilient’ infrastructure.

While decisions taken at the UNISDR are not legally binding, they are seen as a sign of the growing political engagement of governments towards managing risk, and are credited with laying the foundations for climate adaptation strategies.

Deaths from natural disasters have decreased in the past two decades, although the economic costs from storms, typhoons, earthquakes and tsunamis have continued to rise.

Analysts from the Germanwatch Institute say losses linked to extreme weather events between 1993-2012 amounted to US$ 2.5 trillion. Sonke Kreft, team leader at Germanwatch believes a new agreement will have to “actively promote taking climate change seriously as an emerging risk.”

5 Tips For Starting Your Projects

Tip 1: Develop the Project Charter
The Project Charter is a document that includes high level information about the project including key milestones, an overview of the budget and of course, the aims and objectives of the project. You will be key in preparing the document, but it should be owned by the project sponsor who takes responsibility for the project overall. Oh, and if you haven't already, make the time to meet your project sponsor! Ideally you should work on the Charter together so that you have a common understanding of what is to be done.

Tip 2: Identify Stakeholders
Who is going to be involved on your project? The project initiation phase is the perfect time to identify everyone who will have an input to your project or who can influence the work. The Charter gives you a starting point as it will help you see which areas of the business are going to be affected by the new project. You can also talk to your project sponsor to make sure that you don't miss anyone out.

Tip 3: Select the Project Team
The next thing you need to do is to get some team members to work with! Think about the skills you will need in order to be able to complete the different project tasks. Most projects need a variety of different skills from subject matter experts. Then match these requirements to the skills of the available individuals and put together your team.

If you don't know how to start selecting suitable candidates you can ask other project managers or line managers for their advice about who would be able to contribute to the project.

Tip 4: Check the Business Benefits

Why is this project being done? It's important to understand the benefits and the rationale behind doing this project. Talk to your project sponsor if you aren't sure. Understanding the ‘why' will help you explain it to the other team members. You'll find that the team is more motivated if they understand why they are working on something and how it contributes to the business strategy and plans overall. If you can share a common understanding of the project's objectives this is a major step towards getting everyone on board.

Tip 5: Get started!
Now the preparation work is complete, you can get started working with your team and putting together your project schedule. Create a list of all the tasks that need to be done (with input from your team) and then add dates and milestones to form your schedule. You can then allocate tasks to the people who will be doing the work and instruct everyone to get started! Remember to set up your processes for monitoring and controlling the project work too so that you can keep on top of project status at any time.

Starting a new project can be a hectic time. However, it doesn't have to be difficult. If you are clear about the roles and responsibilities of the project manager during this time, you can start your project off perfectly.

JAPANESE ENGINEERS PLANNING TO GET POWER FROM MOON

Japanese Engineers planning to get POWER from MOON. Could our homes soon be powered by the MOON? Engineers plan to ring the lunar equator in solar panels and beam energy back to Earth. Shimizu Construction plans to fit 250-mile-wide belt of solar panels around 6,850 miles of the moon’s surface.Power generated would be sent to Earth using microwaves and laser light.The firm claims it would provide an ‘inexhaustible amount of energy’.

It may sound like something out of science fiction but a Japanese firm plans to cover the Moon in a huge swathe of solar panels and use them to power homes here on Earth.

Shimizu Corporation’s Luna Ring project would stretch almost 6,790 miles around the Moon’s equator and a field of solar panels would form a belt 250 miles wide.

Energy captured by these panels would then be sent to Earth using microwaves and laser lights could be beamed directly to countries where it is needed.

काठमाडौं-हेटौंडा सुरुङमार्गको अग्राधिकार शेयर

३० मंसिर, काठमाडौं । काठमाडौं-कुलेखानी-हेटौंडा सुरुङमार्ग निर्माण गरिरहेको नेपाल पूर्वाधार विकास कम्पनीले संस्थापक शेयरधनीका लागि अग्राधिकार शेयर जारी गरेको छ ।

वाषिर्क १० प्रतिशतका दरले प्रतिफल प्राप्त हुने गरी अग्राधिकार शेयर जारी गरेको कम्पनीले जनाएको छ । कम्पनीका अनुसार शेयरधनीहरुले चुक्ता गरेको शेयर संख्याको शतप्रतिशत सम्म हुने गरी अग्राधिकार शेयर जारी गरिएको हो ।

अग्राधिकार शेयर खरिद गर्न चाहाने संस्थापक शेयरधनीहरुले पुस १६ गतेसम्म कम्पनीको केन्द्रीय कार्यालय टे्रेड टावर थापाथली र शाखा कार्यालयहरु मकवानपुरको हेटौंडास्थित ओमभवन, मकवानपुरकै सिस्नेरीमा सम्पर्क राख्न आग्रह गरेको छ ।

Staff Nurse Vacancy in Various District Hospitals

The Nick Simon Institute (NSI)is an organization working to improve health care in rural Nepal. To retain health workers in the field, NSI's Rural Staff Support Program (RSSP) is an integrated package of support to health care workers in district hospitals. As a part of the RSSP program, we are seeking qualified Nepalese citizens to fill the following positions in an NSI supported district hospital:

JOB POSITION: STAFF NURSE (Five)

LOCATION: Government District Hospital (Myagdi, Mahottari, Dolakha, Pyuthan & Bajhang) 

TERMS: 1 year (renewable) starting immediately.

CORE RESPONSIBILITY:

• Work in a government district hospital as a Nurse.
• Provide day-to-day nursing care to patients as well as consultation of family planning.
• Conduct normal deliveries and identify obstetric complications and manage accordingly.  
• Work with hospital surgical team as the Operation Theater (OT) nurse.

REQUIRED QUALIFICATIONS:

• Staff Nurse from recognised Nursing college.
• Active Registration with Nepal Nursing Council.

PREFERABLE:

• Skilled Birth Attended (SBA) training
• Native working District or nearby districts
• One year of previous work experience
• Experience in OT nursing

PLEASE APPLY WITH:

1) A covering letter explaining your interest and commitment.

2) Updated and concise Curriculum vitae (not more than 2 pages)

3) Name arid contact information of two Referees

SUBMIT TO: 

Nick Simons Institute

P.O.Box: 8975 

EPC: 1813

Sanepa, Lalitpur

Email: application@nsi.edu.np

Closing date for receiving applications: December 25, 2013 by 17:00 hours

Published in The Himalayan Times Daily Newspaper
Date: 2013-12-11

ऋतिक रोसनको डिभोर्स

बलिउड नायक ऋतिक रोशनले पत्नी सुजैनसँगको आफ्नो १३ बर्ष लामो बैबाहिक जीवनको अन्त्य गरेका छन् ।

उनीहरुको डिभोर्सबारे केही महिनादेखि चलेका अनुमानलाई पुष्टी गर्दै ऋतिकले शुक्रबार भनेका छन-’सुजैनले मबाट अलग हुने निर्णय लिएकी छिन्, यो हाम्रो परिवारका लागि सवैभन्दा कठिन समय हो ।’

उनीहरुको बिबाह सन् २००० मा भएपनि चार बर्षदेखि प्रेममा थिए । उनीहरुका दुई छोरा छन् । ऋतिकले आफ्नो गोपनियताको हकको ख्याल गरिदिन पनि मिडियालाई आग्रह गरेका छन् ।

पछिल्लोपटक ऋतिकको बर्थ डे पार्टीमा पत्नीको अनुपस्थीतिपछि उनीहरुको सम्बन्धमा दरार आएको अनुमान गरिएको थियो । पत्नी सुजैन केही महिना पहिले नै ऋतिकको घर छाडेर बेग्लै बस्दै आएकी थिइन् ।

Civil Engineering Vacancy

WESTERN UPLANDS POVERTY ALLEVIATION PROJECT (WUPAP), an IFAD loan Project has been in implementation since 2003 in selected hill and mountain districts of mid and far-western regions. The primary objective of the project is to have more resilient livelihoods and basic human dignity of poor and socially disadvantaged groups through a rights based approach. WUPAP, under its Technical Assistance Program, invites applications from eligible Nepalese candidates for the following position.

POST:-ENGINEER

DURATION:-15 July 2015

KEY RESPONSIBILITY:-The Infrastructure Engineer will have the overall responsibility of assisting district technical staff to ensure the quality standards of the new schemes with O&M in place and ensure the sustainability of the design; ensure the fluality aspects of the infrastructure constructed. 

DUTY STATION:- Project Coordination Unit, Nepalgunj with visit to project district as per necessary. 

QUALIFICATION AND EXPERIENCES:

• Bachelor Degree in Civil Engineering with at least Two years of professional experiences from development sector in program/projects funded by International Funding Agencies.
• Drafting and reporting skills and ability to communicate effectively both in Nepali and English.
• Willing to, travel extensively in rural areas and stay overnights in the villages.
• Practical work experience of the hilly district(s) preferably from Far and mid west.
• Strong command over MS office package, email, internet,
• Willing to work with socially and economically disadvantaged communities.

MONTHLY SALARY: NRs. 45000.00

OTHER BENEFITS:- Accidental Insurance, DSA in field visit, other benefit and leave as per the Project rules. Detail ToR and Syllabus can be downloaded from the project website for individual position.

Interested candidates should send their application, (in case of SDC write an article in 300 words justifying "Why you are going to apply Senior District Coordinator post") with an updated CV (CV format can be download from www.wupap.gov.np.) with three reference of past employer, one passport size photo and self attested photocopy of citizenship, highest degree and experience letters in a sealed envelope indicating the position applied to the following addresses by 20th December 2013.

Western Uplands Poverty

Alleviation Project

WUPAP Liaison Office,

Manbhawan, Lalitpur

Phone: 01- 5535288/5535488

Western Uplands Poverty

Alleviation Project (WUPAP)

Project Coordination Unit,

Ranjha, Nepalgunj

Phone: 565043/565043

Selection procedure:- Selection will be carried out in 3 steps (1) Pre selection and short list will be made and only short listed candidate will be called for next level examination (2) written exam (3) Interview. Only successful candidate will be called for next step exam. Telephone enquiries will not be entertained. Women and candidates from disadvantaged communities are strongly encouraged to apply. WUPAP reserves rights to accept or reject the applications with or without reason.

VACANCY ANNOUNCEMENT in Engineering and Water Resource Program Coordinator//Regional Engineer/Finance and Admin Officer

Market Access and Water Technology for Women (MAWTW)

VACANCY ANNOUNCEMENT

Market Access and Water Technology for Women (MAWTW) Project is a USAID funded 2.5 years (2013-2016) project being managed by  International Development Enterprises (IDE) Nepal in partnership with IWMI, SAPPROS Nepal, NTAG and Samjhauta-Nepal . The overall goal of this project is to promote greater gender equality in the agriculture sector in Nepal, demonstrate the scalability of the representative farmer-group model integrated in agricultural value chains and expand the knowledge and evidence base for greater gender integration into food security programming. MAWTW seeks application from interested and qualified Nepalese individuals for the following positions.

Position	Station	Required qualification	Work Experience	Institutional base
Engineering and Water Resource Program Coordinator - 1	iDE Nepal Central Office, Bakhundole, Lalitpur	Masters Degree in Agricultural or Civil or Water Resource or other related fields of Engineering.	·         Minimum 5 years experience in smallholder water resource development. ·         Manage, coordinate and lead the technical team	iDE Nepal
Regional Engineer-  1	Project Regional Office, Dhangadi	Bachelors Degree in Engineering (Agriculture, Civil, Water resource or related fields).	Should have minimum of 3 years  experience ·         Irrigation and MIT (Treadle pumps, Sprinkler and Drip Irrigation).  ·         Design and estimation of collection center and rural water supply schemes	iDE Nepal
Finance and Admin Officer-1	Project Regional Office, Dhangadi	Minimum graduate in management with major in accountancy.	Minimum 3 years experience ·         Must be well versed with financial laws, rules and acts, ·         Excellent computer knowledge having computer-based accounting software package	iDE Nepal
Program Officer - 2	Kailali & Dadeldhura district	Bachelors degree in any discipline preferably in Agriculture	Should have minimum of 5 years experience ·         agriculture and market extension works ·         gender empowerment activities ·         nutrition and health activities for women and children ·         labor saving technologies ·         supply and participatory market chain approach	Sappros Nepal
Agriculture Technician- 2	Kailali & Dadeldhura  district	Bachelors degree in any discipline preferably in Agriculture	Should have minimum of 3 years experience ·         high value agriculture and market extension works ·         Women Development, Income Generation, Entrepreneur activities etc ·         nutrition and health activities for women and children ·         supply and participatory market chain approach	Sappros Nepal

This vacancy announcement can be viewed at www.idenepal.org and www.jobsnepal.com as well. Interested and qualified candidates are requested to submit their application (indicating the expected gross salary) along with updated CV and recent photograph by email to info@idenepal.org within December 20, 2013.

Interested female candidates and the candidates belonging to disadvantaged communities are encouraged to apply.

Only short-listed candidates will be contracted for further process. No telephone enquiries will be entertained. 

Receptionist Job Vacancy - Save the children

Save the children is an international non-profit organization working in Nepal and Bhutan to create positive and lasting change for children. It advocates for the rights of the children and expresses zero tolerance to any kind of child abuse. Save the Children invites applications from the qualified young, dynamic, reliable and accountable Nepali citizens with the highest level of integrity and ability to deliver quality results for the following position 

Job Position: Receptionist

Required Qualification: At least intermediate level completed with minimum two years experience in related field. 

Duration of service: Short term (Four Months only)

Application Deadline: December 20, 2013

Retrofitting Existing Buildings to Improve Sustainability and Energy Performance

INTRODUCTION

Retrofitting an existing building can oftentimes be more cost-effective than building a new facility. Since buildings consume a significant amount of energy (40 percent of the nation's total U.S. energy consumption), particularly for heating and cooling (32 percent), and because existing buildings comprise the largest segment of the built environment, it is important to initiate energy conservation retrofits to reduce energy consumption and the cost of heating, cooling, and lighting buildings. But conserving energy is not the only reason for retrofitting existing buildings. The goal should be to create a high-performance building by applying the integrated, whole-building design process, to the project during the planning or charrette phase that ensures all key design objectives are met. For example, the integrated project team may discover a single design strategy that will meet multiple design objectives. Doing so will mean that the building will be less costly to operate, will increase in value, last longer, and contribute to a better, healthier, more comfortable environment for people in which to live and work. Improving indoor environmental quality, decreasing moisture penetration, and reducing mold all will result in improved occupant health andproductivity. Further, when deciding on a retrofit, consider upgrading for accessibility, safety and security at the same time. The unique aspects for retrofit of historic buildings must be given special consideration. Designing major renovations and retrofits for existing buildings to include sustainability initiatives will reduce operation costs and environmental impacts, and can increase building adaptability, durability, and resiliency.

RECOMMENDATIONS

Before making what may amount to a major investment in the retrofit of existing buildings for energy and sustainability improvements, it is important to determine if the investment is worthwhile in perspective with other building conditions. Is the building structurally sound? Are seismic upgrades needed to meet current standards and local building code requirements? Do hazardous material like asbestos, polychlorinated biphenyls (PCB) and lead paint have to be contained and removed? Can the work be done in phases to minimize disruption to the occupants? Relocating occupants to other facilities can be a significant expense. If a vegetative roof is being considered, is the roof able to support the additional weight without costly reinforcement? Look for opportunities to reduce the cost of the work by recycling waste and demolition materials.

Once you have determined that other building conditions are not impediments to upgrading for sustainability and improved energy performance, you should have a plan and follow a sequence of activities in order to determine the best options for energy and sustainability improvements.

• First, determine if the existing systems are operating at optimum levels before considering replacing existing equipment with new higher efficiency equipment. This can be accomplished by performing an energy audit. Sometimes, considerable savings in utility costs can be gained by evaluating the performance of the building envelope and existing systems: leaks, clogged/dirty filters, stuck dampers, disabled sensors, faulty or incorrect wiring, or even lack of knowledge on how to properly operate and maintain equipment can all contribute to inefficiencies and increased costs. Audit the performance of the building's water systems as well; since leaking and inefficient systems not only waste water, they also use energy by needlessly running pumps and other electrical equipment.
• Then, if the building is metered, review utility bills from the last two years to determine if consumption (not cost) has risen.

Federal Agencies are required by Executive Order 13514 to have 15 percent of their existing facilities and buildings meet the Guiding Principles by the end of FY 2015, with continued improvement toward 100 percent thereafter. For existing federal buildings, performing an energy audit (assessing existing condition and operational procedures of the building and major building systems and identify areas for improvement) is one of the Guiding Principles for Sustainable Existing Buildings.

• Next, determine air tightness of the building envelope by examining the building envelope, looking for leaky windows, gaps around vents and pipe penetrations, and moisture intrusion. Upgrading heating and air-conditioning systems without addressing problems with the building envelope will result in less than optimum performance of those systems. Employ the methods in ASTM E1827, Standard Test Methods for Determining Airtightness of Buildings Using an Orifice Blower Door and ASTM E779, Determining Airtightness of Buildings Air Leakage Rate by Single Zone Air Pressurization. Consider also doing tracer gas test described in ASTM E741, Standard Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution.

Sustainability and Energy-Efficiency Strategies

• Recommission all energy andand water systems to determine they are operating at optimum performance; then upgrade energy and water systems to minimize consumption.
• Develop a plan to optimize the recycling and reuse of demolition debris and construction wasteto minimize waste sent to landfills.
• Evaluate occupancy patterns, then apply daylight, HVAC and lighting sensors in appropriate locations. Incorporate energy efficient lighting into the project as appropriate for the tasks and functions of the spaces.
• Determine if natural ventilation and fresh air intake are feasible alternatives to reduce heating and cooling loads.
• Investigate renewable energy options that can offset the purchase of fossil fuel-based energy.
• Consider solar shading devices for windows and doors, including those that generate electricity by photovoltaic (PV) devices.
• Replace existing windows with high-performance windows appropriate for climate and exposure. If building requires security upgrade, evaluate blast resistant windows and films. If building is located in a high noise area, evaluate windows that also include adequate exterior to interior noise reduction.
• Analyze the benefits of distributed generation if the building is in a campus cluster or can share the on-site energy produced with adjacent buildings.
• Balance the project's sustainable goals with its security goals including protecting the building and its occupants from natural and man-caused disasters.
• Certain site renovations can improve the energy performance of the building including reducing the heat island effect.
• Determine if a cool roof or green roof are cost-effective ways to reduce heat island effect and stormwater runoff.
• Employ Energy Star and/or a green building rating system for existing buildings like LEED for Existing Buildings: Operations and Maintenance (LEED EBOM) or Green Globes for Existing Buildings to gage the building's level of performance.
• For historic buildings, update systems appropriately to maintain a balance between the need for energy and water savings with the character of the original building fabric.
• Take the opportunity afforded by the building renovation to incorporate sustainable operations and maintenance practices and switch to green cleaning products and methods.
• To ensure a newly renovated building continues to perform as designed, measure the performance of the building regularly.
• If not already metered, plan on installing meters for electric, gas, water and other utilities. Smart meters and submeters are preferable to monitor real-time consumption, control demand and increase tenant accountability (cost control).