european passive house in the california context...• trade schools and guilds train construction...

NorCal ADPSR Presents

Cree 2440 Grant St. Berkeley, Ca. 94703- P: 510-848-2514 F: 510-684-0978 - www.creebyrhomberg.com ©

Copyright 2011

European Passive House In the California

context

Presented by Nabih Tahan, aia

Cree USA

January 18, 2012

Summary of Presentation

Cree 2440 Grant St. Berkeley, Ca. 94703- P: 510-848-2514 F: 510-684-0978 - www.creebyrhomberg.com © Copyright 2011

• Introduction • My perspective on Passive House- Europe and the USA • They are only rating / certification system – PH and LEED • How does PH work? Grant Street as quick example

• Obstacles and lessons learned • Recent PH related developments in Europe?

• Life Cycle Assessment – The big picture • Integrated “Systems Approach”

Experience in Austria – Low Energy Buildings


Developed 2 Condominium Projects in Feistritz/Drau

-1st Project : Transformed barn into 15 units

-2nd Project: 13 new units

-Both project with prefabricated “OPEN” wall panels in “low energy” standard

Existing Barn

Original barn in front - New building behind

Low Energy Standard – • below 30 kWh / ft² / yr heating energy • well insulated, • air barrier, but not so air-tight, • no HRV • Construction was most impressive – pre fabricated to

precision

Lessons from Europe / Austria – Passive House


• Rigid, but effective education system • Building physics is part of the architectural education • Trade schools and guilds train construction workers from the basic

fundamentals to the master level

• Progression from standard house, to low energy house to

passive house, to carbon footprint.

• Recycling began after war - out of necessity

• Energy prices are high – lack of

fossil fuels, but rich in forests

St. Stephen’s Cathedral, Vienna Destroyed, but rebuilt after war


• Won the war

• Mobile Society • Always moving, looking for jobs, schools, opportunities • Why spend money on the building?

• Cheap Energy From Fossil Fuels • Build economical and fast and blast hot air or cold air to stay comfortable

• Government Subsidies – not based on efficiency • Tax deductions on mortgage interest and property taxes • Encouraged faster buying, selling and building

• Building Science • Not part of architectural education • Minimum training for construction workforce

USA - Last 50 years – Leads to LEED

COMPARISON OF PASSIVE HOUSE AND LEED


• PASSIVE HOUSE • Performance - Only energy consumption counts (in Kwh/ft²/year)

• On site energy - for heating and cooling (1.4 in Kwh / ft² / year)

• Source Energy – heating / cooling/ hot water, appliances, lighting – at the source. (11.3 in Kwh / ft² / year)

• Credit for solar thermal but not for PV

• LEED • Prescriptive – Only Points count

• Deals with more issues such as site, water use, materials, recycling, etc. • Do many points guarantee better performance?

• CURRENT TRENDS • In Europe – Tendency towards Life Cycle Assessment and carbon footprint

• In USA – Tendency toward energy performance and Zero Net Energy

Requirements of a Passive House


1. Annual Heating Requirements:

15 kWh/(m²a) = 1.4 kWh/ft²/yr or 4755 Btu/ft²/yr

2. Combined Source Energy:

Source energy is energy consumed on site (such as

heat, hot water, electricity), plus energy consumed in

the generation and transportation involved in supplying

energy to the site.

120 kWh/(m²a)= 11.2 kWh/ft²/yr or 38039 Btu/ft²/yr

3. Building Envelope Air-Tightness:

Air leakage through unsealed joints must be less than

0.6 the house volume per hour, at 50 pascal, measured

by a blower door test

Experiment in Berkeley – Grant Street


Front Elevation Back Yard Back elevation

Back elevation Existing basement, only 7 foot high

Grant St. – P H Decisions - Obstacles


ZONING: • R-2 Allows 2 units • Need 2 parking spaces • Potential for 2nd unit • Make easy PH and

keep back yard land locked? Or

• Cantilever upstairs, add costs and thermal bridging issues?

EXISTING

NEW

Grant Street – PH decision - Obstacles


SOUTH FACING WINDOWS - Original submission accepted: Keep south

windows, upgrade wall - As response to revision for garage, forced

to remove 2 existing south facing windows. - Tried to keep windows but also upgrade

wall - Insulation and air-tightness from inside

Grant Street – PH decisions - Obstacles


DETAILING • Complicated

assemblies

As Built– 1st floor plan


Front bedroom was originally submitted as garage. Plans were then revised to turn into bedroom

As Built– 2nd floor plan


Grant Street – Lifting House and Cantilever


From a Passive House perspective, it would have been easier to meet the standard without the cantilever, and money could have invested in Passive House windows, more sophisticated heating system, etc. But, what about the potential for a 2nd unit as urban infill

Grant Street – Insulation against the ground


INSULATION BELOW SLAB

INSULATION OUTSIDE FOOTINGS

FLOOR BUILD UP ABOVE SLAB WITH

2 LAYERS OF 1 ½” RIGID INSULATION – R 19.6

Grant Street –Structural details - Framing


Difficulties encountered by canteliver • No insulation under footings • Thermal bridging through

posts and beams, could have wrapped beams, but wanted to expose heavy timber

• Difficult to insulate around steel posts, not enough room.

Grant Street - Insulation


FILTER FABRIC STAPLED AND GLUED TO

STUDS

BLOWN IN, DRY, CELLULOSE

INSULATION

Grant Street – Air-tightness


- Sealing plywood from exterior

- Expandable foam at opening

SEAL BETWEEN MUDSILL AND SLAB SEAL ALL PLYWOOD JOINTS AND INTERSECTIONS

SEAL AND FOAM JOINTS AND

INTERSECTIONS

Grant Street - ventilation


Grant Street - Heating


Peak Heating Load: Title 24 – 20,000 btus Passive House - 5000 btu’s

12” water to air heating or cooling coil

Grant Street - Rainscreen


• Rainscreen, but no exterior insulation under cantilever,

Review obstacles to reaching PH standard


Either cantilever, or no 2nd unit Insulate around steel posts Insulation and air-tightness Difficulties due to existing construction

No South facing windows – too close to property line

Code Regulations • Parking Requirements • No windows – property lines Construction difficulties • Existing conditions Where to spend the money – what are the trade offs? • What is most critical, energy use of house, energy

use of site or total impact on the environment? How do these decisions affect the Passive House Standard and PHPP?

Grant Street – Energy Consumption


Grant Street – Lessons Learned


What is the future – What are Europeans doing now?


• PLAYERS • Clients / homeowners • Energy Consultants • Builders • Architect • Engineer

• Systems Approach • Prefabrication • New Buildings • Retrofits

• Life Cycle Assessment

• Impact of the entire building on the environment • New technologies, but not only through spread sheets, but also

through design, construction, product manufacturing, job creation

What can we adapt now, so we don’t wait 5 to 10 years to catch up?

LIFE CYCLE OF BUILDINGS AND PRODUCTS


MATERIAL SELECTION

MANUFACTURE

ON-SITE

OFF-SITE CONSTRUCTION

OCCUPANCY

MAINTENANCE DEMOLITION

RECYCLE / REUSE

DISPOSAL

Big Picture – Forestry Carbon Cycle - Life Cycle Assessment


Passive House is a concept that can improve the performance of all buildings.

AB32

EXISTING HOMES

25% of existing homes must decrease their purchased energy by 70% from 2008 levels 75% of existing homes must decrease their purchased energy by 30% from 2008 levels 100% of existing multi-family homes have a 40% decrease in purchased energy from 2008 levels

2006 – California Global Warming Solution Act sets an economy-wide cap on California greenhouse gas emissions

1

3

2

4

TAKE WORST FIRST

Finger jointed framing lumber

Cross Laminated Timber

Glue laminated timber

Structural members


Manufacturing – Engineered, High Performance Timber Products


TRADITIONAL METHOD

DESIGN – BID - BUILD INTEGRATED DESIGN PROCESS

Methods of Delivering Buildings

“Systems Approach” - New - Prefabrication


“System Approach” - Retrofit - Prefabrication


“Systems Approach” - Cree - Life Cycle Tower


A 20 story building needs approx. 5.000 m3 of glulam beams. Net annual growth on timberland in the United States is estimated at 755,490,565 cubic meters. 2,069,837 cubic meters per day 86, 243 cubic meters per hour 1,437 cubic meters per minute So, it would take about 3.5 minutes of growth to replace 5,000 cubic meters

“Systems Approach” - Cree - Life Cycle Tower


NorCal ADPSR

Cree 2440 Grant St. Berkeley, Ca. 94703- P: 510-848-2514 F: 510-684-0978 - www.creebyrhomberg.com ©

Copyright 2011

European Passive House In the California

context

Presented by Nabih Tahan, aia

Cree USA

January 18, 2012

The Natural Change in Urban Architecture

Nabih Tahan, AIA

2440 Grant St. Berkeley, Ca. 94703

Tel: 510-848-2514 510-684-0978 cell

Email: [email protected]

www.creebyrhomberg.com

mailto:[email protected]

http://www.creebyrhomberg.com/

european passive house in the california context...• trade schools and guilds train construction...

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