PASSIVE HOUSING – GENERAL DESIGN PRINCIPLES

Passive housing, zero energy housing, sustainable housing, green homes - these may all be slightly different by definition, but architecturally the fundamental basics are pretty much the same.  Consumer awareness has become heightened around the concept of a passive home, and there is more support durning the design process for these considerations. 

 

 

 

Masterspec asked architect Jennifer Hanson from A Studio Architects, co-designer of the Zero Energy house in Auckland's Point Chevalier, to explain some of the guiding design considerations, most of which are inherent in the architectural design process.

“First and foremost it starts with the site, and context” explained Jennifer. “Good site and contextual analysis will help to orientate the house in such a way that passive solar gain can be maximised.  This often needs to be balanced with views, privacy, prevailing winds and other site specific considerations”.

Design efficiency. A compact design will reduce space heating requirements, reduce the amount of material used in the build, and reduce the overall house footprint.  According to Jennifer “a thoughtful, well considered, small space can feel spacious without necessarily being large”

Orientation. The orientation of the interior layout of the house is equally as important as the site orientation.  “Living spaces should follow the sun, and lesser used rooms, such as bathrooms and storage areas, can act as buffers on the south side of the house”.

Sun Interaction. Consider how the sun will interact with the house. “How will the sun get in, how will it be kept out, how is it held in the interior space, how can heat gain be removed when it's not wanted and how best can it be captured to heat water and photovoltaics”.  Key to these considerations are windows, insulation, thermal mass, ventilation techniques and your chosen heating system.

Insulation.  This is a key line of defence against heat loss. “The NZBC contains minimum insulation standards - clients need to be aware that these values are not absolute targets, and higher insulation values will result in a more comfortable home.  Also be aware that heat is lost through thermal bridging in the framing.  If you can minimise points where there is no insulation between wall cladding and wall lining, the insulation will be more efficient, and heat loss will be reduced.  If using pre-nail frames, ask to review the set out drawings, and remove any unnecessary doubling up of studs, that may have resulted from the computer's standard set out of framing and how it relates to window and door openings.  This will help reduce thermal bridging”.

“Heat rises, so good insulation in the ceiling is key.  Again reduce thermal bridging where possible, and ensure that the roof can still breath”.

At the opposite end of the house, a concrete slab can lose heat both through its base and its edges, and both should be considered when insulating the slab.  “The slab can act as a good thermal mass, if it is finished with a solid material or left as exposed concrete. We want the heat to be released to the inside of the house, not to escape outside”. 

Reducing heat loss.  In winter, once the natural heat from the sun has been captured, don't let it go!  “Gaps and windows are the biggest sources of heat loss.  Wrap up the building well during construction, tap gaps and aim for air tight construction.  Windows are great for letting in sun and light, but consider the size of the window in relation to its orientation.  A higher percentage of glazing on the north wall and a low percentage of glazing on the south wall will logically position the windows where they can be of most use to the building thermally.  Also consider the heat loss that the window will cause.  Window furnishings will help in this regard, but so will the specification of the window itself.  Consider thermally broken frames, timber instead of aluminium, double or triple glazing, and argon gas filled units”. 

Heating and ventilation systems.  Do your research, advises Jennifer, or engage a specialist.  “Specialists can provide a wealth of knowledge in solar hot water and photovoltaic systems.  In this Zero Energy project, the team at Solar City worked with us to develop an efficient roof scape of tech-savvy solar systems, the engineering of which is well beyond our understanding.  We helped to integrate the systems into the architecture of the house”.

Material selection.  Reducing toxins used during the build will result in a healthier home.  “If a natural alternative is available for a synthetic building material, it is worth considering.  When choosing between products” says Jennifer “consider the life of that product...what is in it, how far did it travel to get here, what happens to it at the end of the building life cycle”?

Landscape.  The location and type of new trees on the property should be carefully considered with respect to the shading effects on the house and outdoor living areas, both to provide some respite in summer in outdoor areas, but to also reduce shading the house in winter, and keeping solar receivers unshaded at all times.

Finally, establish and check performance criteria.  Some performance targets require an in-depth knowledge of thermal engineering to achieve.  “We would never attempt to meet a clients specific target without advice from a more scientificly-inclined mind.  There are a number of companies across NZ with engineers who can help guide you through the design process and run calculations to check the performance of the house along the way.  In our recent experience with the zero energy house, Jo Woods from ECubed kept things in check, with a super close eye, as it was also to be her own home”.

 Images courtesy of A Design Studio Limited.


  »GOOGLE VERIFIED
  »ENGINEERING TERMS AND CONDITIONS
  »REVISITING OUR HERITAGE
  »FURTHER CHANGES PROPOSED TO NZBC C PROTECTION FROM FIRE
  »REDUCING PARTITION WALL FAILURE IN SEISMIC EVENTS
  »BUILDING CODE UPDATED REFERENCES
  »MEDIUM DENSITY HOUSING RESOURCE PAGE
  »SPECIFICATIONS HOW-TO
  »DETAILED ENGINEERING EVALUATION TOOLS FROM SESOC
  »BIM FOR ALL - DUMMIES OR NOT
  »MASTERSPEC'S PRODUCT RANGE SUPPORTS MULTI-DISCIPLINARY TEAMS
  »SPECIFICATIONS AND CONTRACTS
  »BUILDING ACT 2004 AMENDMENTS
  »SURFACE FIRE PERFORMANCE OF INSULATION IN PLENUMS AND DUCTS
  »CHANGES TO THE BUILDING ACT – HOW DO THEY AFFECT ARCHITECTS, DESIGNERS AND DESIGN/BUILD
  »WHAT IS THE PURPOSE OF A SPECIFICATION???
  »NZBC C PROTECTION FROM FIRE - AMENDMENTS DECEMBER 2013
  »AMENDMENTS TO NZS 4211
  »STRENGTHENING NEW ZEALAND’S STANDARDS SYSTEM – TRANSITION PROJECT
  »2014 INTERNATIONAL BIM REPORT
  »UPDATED GUIDANCE FOR EXEMPT BUILDING WORK
  »TACTILE GROUND SURFACE INDICATORS (TGSIS)
  »STREAMSIDE PROTECTION AND GUIDES TO RESTORATION
  »SEISMIC RESTRAINTS FOR GAS, WATER HEATERS & APPLIANCES
  »CHANGES TO NZBC C PROTECTION FROM FIRE - 1 JULY 2014
  »CHANGES TO H3.1 FOR SOLID TIMBER FRAMING
  »FIRE SAFETY AND DESIGN – FURTHER READING
  »AS 3566.2 WITHDRAWN BY STANDARDS AUSTRALIA BUT IN E2/AS1?
  »AIR CONDITIONING REFRIGERANT SAFETY
  »WHAT IS GOING ON WITH HEALTH & SAFETY?
  »FURTHER WORKED EXAMPLES TO ACCOMPANY THE SEISMIC DESIGN OF RETAINING STRUCTURES GUIDANCE
  »PASSIVE HOUSING – GENERAL DESIGN PRINCIPLES
  »SPECIFYING FIRE BLANKETS
  »DESIGN AND BUILD - REASONS FOR CONSENT DELAYS
  »AS/NZS 2312 SPLIT UP AND AMENDED
  »FIRE PERFORMANCE OF FLOOR COVERINGS LAID OUT
  »CODEMARK CERTIFICATION POPULAR WITH PRODUCT PARTNERS
  »LOW EMISSIVE GLASS COATINGS - SURFACE 2 OR 3 – WHAT SHOULD IT BE?
  »INTERIOR NOISE CONTROL - TRYING TO UNDERSTAND ACOUSTICS
  »MASTERSPEC INTERVIEW: ANDREW MAYNARD
  »DRAINAGE, LAYING OUT THE OPTIONS
  »ELECTRONIC LEAK DETECTION OF MEMBRANES
  »INTERIOR ELEMENTS - BUILDING CODE REQUIREMENTS CHECKLIST
  »NEW GENERIC SECTION 4239 SOFFIT CLADDING
  »SECTIONS CHANGE AS SOME INSULPRO PRODUCTS REBRANDED AS MAMMOTH
  »MASTERSPEC RELEASE 12 NEW SERVICES ENGINEERING WORK SECTIONS.
  »STRUCTURALLY FIXED CAVITY BATTENS
  »CHANGES TO THE LAMINEX GROUP
  »WORK SECTION UPDATES AND DELETIONS FOR JULY 2015
  »ALTERNATIVE TEST METHODS FOR ACHIEVING NZBC C GROUP NUMBERS.
  »CONCRETE SLABS - FREE JOINTS OR SHRINKAGE CONTROL JOINTS???
  »DRAINAGE GENERAL NAME CHANGE
  »ROOF SAFETY MESH - AS/NZS 4389 UPDATED
  »PLUMBING AND DRAINAGE - AS/NZS 3500.1 AND AS/NZS 3500.2 UPDATED
  »NEW BASIC SECTION FOR PLYWOOD AND PARTICLEBOARD FLOORS
  »GREEN BUILDING REQUIREMENTS IN THE RESIDENTIAL SECTOR
  »NEW SECTIONS FOR MASTERSPEC BASIC AND INTERIORS USERS
  »HEAT PUMP WATER HEATERS NOW AN OPTION
  »WELDING GALVANIZED OR THERMAL SPRAYED STEEL
  »MAJOR CHANGES TO THE CARPENTRY BASED SECTIONS IN MASTERSPEC BASIC AND INTERIORS
  »A COLLECTION OF COUNCIL DEVELOPMENT, SUBDIVISION AND ENGINEERING GUIDES
  »NEW NZS 4407 - ONE ROAD AGGREGATE STANDARD TO UNITE THEM ALL
  »PLUGGING INTO ELECTRIC CARS
  »PUTTING MORE INTO 2242 BACKFILLING
  »AS/NZS 3500.4 HEATED WATER SERVICES UPDATED
  »MAJOR CHANGES TO THE CONSTRUCTION CONTRACTS ACT
  »AS/NZS 1668.1 VENTILATION AND AIR-CON FIRE AND SMOKE CONTROL
  »HEALTH AND SAFETY AT WORK ACT 2015 AND THE SPECIFICATION
  »COMPATIBILITY AND ADHESION OF WET SEALS AND SILL TAPES IN WINDOW INSTALLATIONS
  »JMF TIMBER WINDOW AND DOOR JOINERY CAN BE SPECIFIED ON A ‘TEST’ BASIS
  »STEEL STRUCTURES - NZS 3404.1: 1997 VERSES NZS 3404.1: 2009
  »ASBESTOS REMOVAL NEW LICENCE REGIME
  »MBIE PRODUCT ASSURANCE SEMINARS FOR SUPPLIERS/MANUFACTURERS
  »RESIDENTIAL CONSTRUCTION HANDOVER
  »A BIG MONTH OF CHANGES TO STANDARDS
  »INTERNATIONAL BIM OBJECT STANDARD TO BE RELEASED
  »NON-COMPLIANT CONCRETE REINFORCEMENT
  »TIPS FOR SPECIFYING FIXED AUDIENCE SEATING
© 2017 Construction Information Limited
Construction Information Limited Construction Information
Powered by streamSWEET CMS  
Feedback