Sustainable Cold Climate Construction
Karen RollinsSustainable Summits Conference 2016
Aoraki Mount Cook National Park New Zealand
Cold Climate Construction
Alpine Construction
Sustainable Construction
Introduction
Cold Climate
Subarctic/arctic>12,600 heating degree days
Very Cold>9,000 heating degree days
Cold>5,400 heating degree days
SNOW ZONE
ALPINE
SUBALPINE
MONTANE
FOOTHILLS
Polar Desert
Cold Climate Construction
A. Cold Temperatures(How cold affects design and operation of buildings)
Two design strategies for cold climates:
B. Heat Loss ControlC. Moisture Control
A. Cold TemperaturesChallenges:• Frozen precipitation
(snow, frost, hoarfrost, permafrost, spindrift, drifting snow, ice)
• Extreme temperature shifts
• Wind, wind‐driven rain (DRWP)
• Freeze/thaw cycles• UV radiation• Maintenance (remote)
Design Considerations:• Robust building materials and
mechanical systems– Don’t crack in cold T– Expansion and contraction
• Roof designed for snow load• Structural strength (wind pressure)• Special design for building
envelopes to accommodate all seasons
• Backup & redundancy
Spindrift and Snowdrift
• Mountain climber: Loose powdery snow incapable of holding protection
• Engineer: Fine wind borne snow capable of entering a building through any opening in the building envelope
B. Heat Loss Control
Overall heat loss control strategy:1. Control thermal building envelope
– Heat Loss mechanisms• Conduction• Convection• Radiation
2. Control air leakage
1. Control Thermal Envelope
1965 1980 1985 1990 Passive House
Heat Loss Through Conduction
Thermal Bridge
Dust Marks
Solutions for Thermal Bridging
2. Control Air Leakage
Solutions for Air Leakage
AIR BARRIER• impermeable to air flow• continuous over the entire building enclosure• able to withstand forces during and after construction
• durable over the lifespan of the building
Solutions for Air Leakage
Ice Damming
COLDER AREA
WARMER AREA
4. WATER GETS TRAPPED AND BACKS UP UNDER SHINGLES
1. HEAT LOSS
2. UNDERSIDE OF ROOF IS WARMED AND MELTS SNOW
3. WATER FREEZES AT EAVES AND FORMS ICE DAM AND ICICLES
Causes water damage in the attic
Solutions for Ice Damming
Continuous air barrierInsulationVentilationHeat tape
SOFFIT VENT
GABLE VENT
RIDGE VENT
ROOF VENT
Insulation VentilationEave ProtectionHeat tape
Water Shield
C. Moisture Control
Overall Moisture Control Strategy:• In cold climates the goal is to make it as difficult as possible for the building assemblies to get wet from the interior.
• In cold climates building assemblies dry towards the exterior, therefore permeable (breathable) materials are specified as exterior sheathings.
Condensation
a) Increase condensing surface temperatureb) Vapour barrier to keep moisture out of wallsc) Ventilation to remove moistured) Source control
Strategies to Control Condensation
a) Increase Condensing Surface Temperature
Inside +20C
Outside ‐20C
b) Vapour Barrier
• 6 mil polyethylene installed on warm side of insulation
• Continuous, all joints and penetrations sealed
Inside +20C
Outside ‐20C
c) Ventilation to Remove Moisture
Heat Recovery Ventilator
d) Source Control
EXHAUST
WARM AIR RISES
AIR INTAKE
Sustainable Construction
Increase EfficiencyIncrease Efficiency
Energy
Water
Building Materials
Reduce ImpactReduce Impact
Environment
Human Health
Life‐cycleLife‐cycle
DesignBuild
Maintenance Demolition
…Striving towards
Priorities
• People priorities– Health and safety– Comfort– Affordability
• Building priorities– Durability– Renovation– Decommissioning
• Environmental priorities– Local, regional, global environment
Features of Sustainable Construction
• Preserve natural vegetation on site• Rain water collection• Reduce construction waste• Recycled, durable, local building materials• Efficient furnace• Reduce heat loss through building envelope (insulation and air sealing)
• Renewable energy, reduced use of fossil fuels• IAQ plan, reduced air pollution, low VOC
Most Sustainable Structure
Local building materials (zero transportation costs)Recyclable building materialsDurable materialsZero G.H.G. to manufacture building materialsZero environmental impact (local, regional, global)Easy to decommissionAffordable
Alpine Construction
Design Challenges:• Off‐grid• Remote• Extreme low temperatures• Extreme wind• Snowfall, drifting snow, spindrift• Moisture producing activities• No live in custodian (easy to operate technologies)• Periodic use (thermal conditions not steady) • National Parks location (building restrictions)
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Wapta Icefields near Mount Des Poilus (2580m, 54°L)Alpine Club of Canada (owner, general contractor)BEES (design criteria and building specifications)Architect: Greg JablonskiTeam: structural engineer, mechanical engineer,
environmental assessment, alternate energy designer,surveyor, weather study, SIP manufacturer, propane plumber, helicopter, many volunteers
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Guy Hut at Mount Des Poilus
Build a structure that enhances visitor experience and acts as a model for other off‐grid facilities
Vision
• Environmental integrity• Advanced construction methods and materials: sustainable construction features
• Reliable and easy to operate technologies • Energy efficient • Healthy indoor environment
Design Goals
!
Vision Build!a!structure!
that!enhances!visitor!experience!and!acts!as!a!model!for!other!off6grid!mountain!facili8es!around!the!
world!
Goal Advanced!
construc8on!methods!and!materials!
Goal Superior!Energy!
Effic
i
ency!
Goal Easy!to!operate!and!maintain!technologies!
Goal Excellent!indoor!air!
quality!
Goal Environmental!Integrity!
Structural!Insulated!Panels!
Reduced!thermal!bridging!
Boiling!snowmelt!to!treat!potable!
water!
Structural!Insulated!Panels!
Super!insulated:!Passive!House!
Standard!
Structural!Insulated!Panels!
Structural!Insulated!Panels!
Solar/wind!hybrid!
renewable!energy!system!
Greywater!dispersion!
field!
Barrel!fly6out!system!
Propane!stove!
Solar/wind!hybrid!
renewable!energy!system!
Propane!stove!
Heat!recovery!ventilation!!
Reduced!thermal!bridging!
Heat!recovery!ventilation!
Recycled!content!building!materials!
Super!insulated:!Passive!House!
Standard!
Super!insulated:!Passive!House!
Standard!
Super!insulated:!Passive!House!
Standard!
Reduced!site!
disturbance!
Low!VOC!emitting!building!materials!
Daylight!and!views!
Moisture!control!
strategies!
Indoor!environmental!monitoring!!
Barrel!fly6out!system!
Grey6water!dispersion!
field!
Heat!recovery!ventilation!!
Structural!Insulated!Panels!
Propane!stove!
Solar/wind!hybrid!
renewable!energy!system!
Reduced!thermal!bridging!
Moisture!control!
strategies!
Recycled!content!building!materials!
• Considerations for ecological integrity – winter use, 700/yr. • Greywater treatment: dispersion field• Low visual impact, small footprint• Construction waste management, recycled building materials (flooring), durable building materials, locally manufactured building materials, low VOC materials (paint, caulking)
• Energy efficient building envelope• Heat primarily from the sun (80‐90%)• Propane (burns cleanly) for cooking, lighting, heating• Renewable energy system: solar and wind (lighting, ventilation)
• Human waste removed from the site
Sustainable Construction Features
• Well‐insulated thermal building envelope• Reduced thermal bridging• Air tight construction: air barrier, vapour barrier• Heat and ventilation to prevent condensation• Covered front entrance and air lock entry• Technologies are easy to operate and maintain• Redundancy in lighting and heating and ventilation
• Moisture control strategies
Cold Climate Construction Features
Moisture Control Strategies
• Heat• Ventilation• Super‐insulation• Minimal thermal bridging• Keep furnishings (kitchen cabinets, sleeping bunks) away from exterior walls
• Drying room for wet gear to isolate moisture from the rest of the hut (ventilated)
Well‐insulated
R‐16 R‐24 R‐24 R‐32 R‐45 R‐50
Passive House
1965 1985 20051988 Bow Hut
2014 Des Poilus Hut
Structural Insulated Panels (SIPs)
• Walls, floor, roof• Structural framing, insulation,
air barrier, vapour barrier • Short assembly time• Strong• High insulating value• Air‐tight• Reduced thermal bridging• Moisture control• Fire resistant
Healthy Indoor Environment
• Temperature control – high quality thermal envelope, air lock entry, heat source (sun and propane stove)
• Ventilation– Kitchen, bedroom, drying room exhaust– Fresh air warmed by propane stove
• Moisture control to prevent condensation and mould• Propane instead of wood burning ‐ particulates• Layout designed by an architect• Day lighting & views• Low VOC building materials
• Alpine construction can feature sustainable construction and cold climate construction
• Cold climate during construction can play a significant role
Conclusions
• Cold Climate Housing Research Centre –Fairbanks Alaska
• ASHRAE: Cold‐Climate Buildings Design Guide• Builder’s Guide to Cold Climates – Joseph Lstiburek
• Canadian Center for Housing Technology• CMHC Canadian Wood‐Frame House Construction
Resources
Thank YOU!