New School: Building an

architecture for sustainable

living ?

IOWA ACADEMY OF SCIENCE 126th ANNUAL MEETING, Fort Dodge, Iowa

April 11 – 12th 2014

Dr. Andrea Wheeler, Naghmeh Pak, and Megan Fowler Iowa State University, Department of Architecture

NSF EPSCoR Start-Up Grant: “Iowa’s New

School Buildings: A Future Invested in

Sustainability?”

• This paper is supported by funds ($12,000) awarded to the authors as

part of the NSF EPSCoR Energy Utilization Platform Building

Science Plank for Professor Andrea Wheeler’s project entitled:

“Iowa’s New School Buildings: A Future Invested in

Sustainability?”

• Objectives of the project:

– To identify key concerns and strategies within the US context for the design of

contemporary sustainable schools, comparing with schools in an international

context.

– To develop a program and methodology for a post-occupancy assessment of

Iowa schools addressing both energy performance and occupant behavior.

Sustainability in the US

• European perspective: From the perspective of Europe, the US has

been slow to address its carbon emissions.

• Worldwatch Institute report assesses US sustainability:

– US consumes around 207% of its ecological capacity

– Criticized for minimal support for global environmental institutions and

treaties

– Poor performance in mitigating air pollution and water and ecosystem stresses

– 2010 National Geographic survey of 17 developed and developing

countries - Americans ranked worst in green consumption habits

The President’s Climate Action Plan

• However, on June 25, 2013, President Obama announced a plan to

reduce carbon emissions, increase the use of clean energy sources,

and mitigate the effects of climate change. At Georgetown University,

he stated:

• “… the world still looks to America to lead […] I am convinced this is

the fight America can, and will, lead in the 21st century. […] We’ll

need scientists to design new fuels, and we’ll need farmers to grow

new fuels. We’ll need engineers to devise new technologies, and

we’ll need businesses to make and sell those technologies. We’ll need

workers to operate assembly lines that hum with high-tech, zero-

carbon components, but we’ll also need builders to hammer into

place the foundations for a new clean energy era” (Obama, The White

House, Office of the Press Secretary, 2013).

Schools represent the test for a question

about design and encouraging sustainable

lifestyles

• To develop a method for assessing green schools we need to understand the existing

frameworks for assessment and best practice guidelines.

• We also recognize, Joo Hwa Bay states: “Human behavior and habits can enhance or

frustrate environmental sustainability efforts in the reduction of carbon footprint,

indoor air quality, emissions, and impact to the natural environment” (Bay, 2010,

190).

• Without building user communities educated about sustainability, buildings risk

being poorly utilized and innovative energy technologies misunderstood.

• Moreover, as Lucas argues: “…environmental behaviours [sic] will require complex

and innovative policies and practical interventions across a wide range of different

sectors and at every level of society (i.e. individual, household, community,

organisational [sic], institutional and across whole systems).” (Lucas et al, 2008,

456).

Different Frameworks for Sustainable

Schools in U.S.

• CEFPI (The Council of Educational Facilities

Planners International)

• LEED for schools (Leadership in Energy and

Environmental Design)

• ENERGY STAR

• CHPS (Collaborative High Performance

School)

• AASHE (Association for the Advancement of

Sustainability in Higher Education)

• Passivhaus

ENERGY STAR

• The analysis for K-12 schools is based on data from the Department

of Energy, Energy Information Administration’s 2003 Commercial

Building Energy Consumption Survey (CBECS).

• The analysis includes adjustments for:

• Building Size

• Whether or not the School is Open on Weekends

• Whether or not there is Energy Used for Cooking

• Whether or not the school is a High School

• Weather and Climate (using Heating and Cooling Degree Days, retrieved based

on Zip code)

• Percent of the Building that is Heated and Cooled

• …

LEED for Schools

• 79 possible points in 6 sub-categories:

– Sustainable Sites

– Water Efficiency

– Energy & Atmosphere

– Materials & Resources

– Indoor Environmental Quality

– Innovation & Design Process

Collaborative High Performance School

(CHPS manuals)

• The Collaborative for High Performance Schools (CHPS) is leading a

national movement to improve student performance and the entire

educational experience by building the best possible schools.

• No Iowan manuals, not even in Illinois

Technical performance (in terms of

categories of performance CHPS)

• Similar sub-categories compered to LEED :

– General conditions

– Site planning

– Interior Surface and furnishing

– Lighting and daylighting

– Building Enclosure and insulation

– HVAC

– Other Equipment and systems

The Passivhaus Standard

• Passivhaus Institut began in Darmstadt, Germany in 1996

• Independent research institute, voluntary performance-based standard of energy efficiency in buildings

• Passivhaus buildings require little mechanical heating/cooling

• Integrated design process: – Passive solar design and landscaping

– Superinsulation and airtightness

– Advanced window technology and natural ventilation

– Internal space heating

– Low-energy lighting and electrical appliances

• Tens of thousands of Passivhaus certified projects in Europe, residential and commercial

• 78 certified Passivhaus buildings in the US, mostly single-family homes

What is the Passivhaus Standard?

• Basic principles:

– Good insulation with minimal thermal bridges

– Passive solar and internal heat sources

– Excellent level of airtightness

– Good indoor air quality – mechanical ventilation with efficient heat recovery

• No specific requirements for hot water, lighting, and appliance

consumption

– An overall limit on “Primary Energy” consumption encourages energy

efficiency in all of these areas

What is the Passivhaus Standard?

Design Component Limiting value

Walls, Roof, Floor (U-values)* ≤0.15 (W/m2K)

Glazing unit ≤0.8 (W/m2K)

Installed glazing ≤0.85 (W/m2K)

Doors ≤0.8 (W/m2K)

Infiltration (ach-1

) ≤0.6 @ n50

Thermal bridging (linear ψ

value)

≤0.01 (W/mK)

MVHR coefficient (η HR) ≥0.75

Ventilation electric limit 0.45 Wh/m3

Appliances High efficiency recommended

Lighting High efficiency recommended

On site renewables No requirement but SHW

typical

Energy performance targets and air

changes per hour

Specific Heating

Demand

≤ 15 kWh/m2. yr

Specific Cooling

Demand

≤ 15 kWh/m2. yr

Specific Heating Load ≤ 10 W/m2

Specific Primary

Energy Demand

≤ 120 kWh/m2. Yr

Air Changes Per Hour ≤ 0.6 @ n50

Passivhaus Standard for Schools?

1. Each modern school should have controlled ventilation which meets the criteria for acceptable indoor air quality.

2. The air flow rates of the school's ventilation system should be based on health and educational objectives and not on the upper limits of the comfort criteria. The result is: CO2 limit values between 1200 and 1500 ppm and designed air flow rates between 15 and 20 m³/person/h (possibly more for a higher average age of the pupils).

3. In the interest of justifiable operational costs, the ventilation systems in schools must be operated periodically or according to demand.

4. Designed so that it is also possible to heat up the rooms to a comfortable level in the morning.

5. The building envelope and heat recovery are designed so that the annual heating demand according is less than or equal to 15 kWh/(m²a) (based on the total net useable area).

6. Secondary conditions: a) In order to avoid temperature asymmetry, a window U–value of less than or equal to 0.85 W/(m²K). b) The building envelope must be built in a very airtight way. n50 < 0.6 h-1 is required and < 0.3 is recommended.

7. The annual primary energy demand for all non-renewable energy supplied to the school building should be less than or equal to 120 kWh/(m²a) (based on the total net useable area).

8. In order to ensure comfort in summer in a Passive House school, the frequency of temperatures over 25°C should be limited to less than 10% of the hours of use.

9. The total effective area-specific heat capacity of the space-enclosing components should be >150 Wh/(m²K) { 540 kJ/(m²K) } (based on the base area of the classroom). Alternatively, additional cooling facilities must be provided (besides night-time ventilation and shading).

Passivhaus Schools – UK (Architype)

• Bushbury Hill Passivhaus School (2011)

– Comfortable environment without expensive energy-saving add-ons

– Built within existing budget and timeline

• Oakmeadow Passivhaus Primary School (2011)

– Also within existing budget and timeline

– Close collaboration with client and fully integrated design team

• Swillington Passivhaus Primary School (2011)

– Replaced an existing 1970s building, includes a nursery, community facilities, a

new parking lot, and landscaping

• Wilkinson Passivhaus School (2013)

– Replaced a school destroyed by a fire in 2010

– Local authority insisted on Passivhaus design

Center for Energy Efficient Design (CEED) in Franklin County, Virginia

US Comparison - Passivhaus School – only one in the US

Center for Energy Efficient Design (CEED)

• Envisioned as a tool for learning, open to surrounding

communities

• 70% energy savings by using Passivhaus standards

• Challenges with US expectations of comfort

• Equipment and products needed to be specially created while

widely available in Europe

• Building today manufactures more energy than it uses

• The project team hopes its success educates and encourages

more Passivhaus schools in the US

– The more common Passivhaus becomes, the easier it will be to implement

Passivhaus in Different Climates

• Initially developed for mid to northern European climates, but can work extremely well for hot, humid climates as well – Airtightness and insulation work equally well in protecting buildings from

overheating, provided shading is adequate

• Mechanical ventilation can pre-cool supply air and adjust humidity levels as needed – Energy Recovery Ventilation may be preferable to Heat Recovery Ventilation to

reduce the humidity load of ventilation on the mechanical system

• Cross-ventilation and night purge strategies may apply

• When a residual cooling load is needed in particularly hot regions, the Passivhaus standard permits 15 kWh/m2.yr of cooling energy to be used – This has proven sufficient in almost all cases due to Passivhaus’ ability to reduce

unwanted heat gains

Are Passivhaus standards appropriate for

Iowan schools?

• The climate of Iowa makes strategies like natural ventilation difficult

• There is good opportunity for energy generation – wind, solar

• Insulation and air-tightness are already important for designing in

Iowa.

Iowan Schools – Case Studies 1

Ballard High School, Huxley, Iowa

HAILA Architecture

Iowan Schools – Case Studies 2

Van Allen Elementary

North Liberty, Iowa

Iowan Schools – Case Studies 3

North Central Junior High

North Liberty, Iowa

The future for sustainable architecture? The

future for education?

• No Iowan manuals, no guidelines specific for the climate and culture, but there is a need for evaluation and post-occupancy assessments of schools in Iowa.

• Education for sustainability and the problem of building an environment and community for sustainable lifestyles to emerge underpins this work.

• Passivhaus schools to be studied in the UK over the summer.

• After an evaluation of the different frameworks for envisioning what constitutes a sustainable school – what qualities of the environment may be absent - and whether frameworks are flexible enough for a variety of US environments and cultural contexts – the development of a program of post occupancy evaluation of schools and the outline for our own framework will be the focus of our work.