BU612 Load paths
Buildings must be designed to withstand a variety of loads that are imposed both vertically and horizontally. This bulletin defines a load path, describes the loads imposed on framed buildings and explains how loads are transferred through the building via load paths.
It describes the design requirements to ensure effective load paths are created.
This bulletin covers:
- loads on buildings
- load paths
- wind loads
- load transference
- designing load paths
- specific design required.
BU620 Managing wind effects around buildings
Reducing the impact of wind at a site improves the micro-climate around the building, reduces wind loads on the structure, improves energy efficiency by reducing heating demands and gives an improved, safer living environment. Wind impact can be reduced by the siting, layout and shape of buildings, planting, fences and screens and reshaping of land forms.
This bulletin replaces Bulletin 321 Reducing the impact of wind at building sites.
This bulletin covers:
- the nature of airflows
- site analysis
- site planning
- building design
- fencing
- planting
- modifying landforms.
BU563 Building on exposed sites
This bulletin outlines some important factors that should be considered when designing and constructing buildings on sites that are exposed to high winds. As wind speeds and the loads generated are higher, traditional practices may not be sufficient to prevent a building from structural or envelope damage or leaking.
This bulletin replaces Bulletins 405, 406, 407 and 408.
The bulletin covers:
- the effect of high wind on buildings
- design considerations, including collecting site-specific data, mitigating wind effects, structural design, weathertightness, insulation and ventilation
- exposed coastal sites
- working on windy sites.
Site results
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SR25 Designing multi-storey buildings for wind effects
<p>Available calculation methods for predicting the action of along-wind, across-wind and torsional forces on buildings have been reviewed and a comparison made between the response obtained by these methods and by assuming wind loads specified by various codes, including the current Australian (1989) and Canadian (1985) codes and the proposed revision to the New Zealand code.</p><p>The work includes a review of the current limits for building inter-storey drifts and criteria for occupant comfort. Design guidelines have been prepared giving classification procedures for identifying wind-sensitive structures and methods for estimating the wind motion displacements and accelerations.</p><p>Worked examples are included to illustrate the recommended methods for typical tall buildings.</p>
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Process for template modelling
<p>This page has detailed instructions for using OpenStudio, SketchUp and EnergyPlus.</p>
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SR119 Full-sized house cyclic racking rest
<p>Earthquake and wind loads for timber-framed house designs in New Zealand are specified in NZS 3604:1999. Various lining and cladding manufactures publish bracing strengths for their wall systems based on the BRANZ P21 racking test.</p><p>The P21 tests are carried out on a short length of wall with contrived end restraints to simulate continuity of actual construction. To verify that this design approach is realistic, an existing house was relined and cyclically racked to failure.</p><p>This paper compares the actual house strength with the strength determined using the NZS 3604:1999 design provisions. Free vibration tests to measure the house natural frequency and damping are also reported.</p>
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SR131 BRANZ test and evaluation method EM3-V2 for bracing rating of walls to NZS 3604
<p>This report presents the basis for changing the current BRANZ test and evaluation procedure used to establish bracing ratings. This is known as the BRANZ P21 test method and is used to obtain the bracing ratings of timber-framed, plank or panel, wall systems for houses (and other low-rise structures) to meet the wind and seismic demand stipulated in the timber-framed building standard NZS 3604:1999.</p><p>The demand wind and seismic loads in NZS 3604 were based on the loadings specified in the New Zealand loadings standard NZS 3203:1992. This report presents a revised wind and earthquake test and evaluation method (called EM3) which is based on engineering analysis to ensure the as-built house strength constructed with EM3 assessed walls will achieve the NZS 4203:1992 intent in a reliable but economical manner.</p>
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Carbon Challenge seminar - optimisation strategies
<p data-block-key="ndhio">Part of the Carbon Challenge seminar includes a session on optimisation strategies for lower-carbon homes. </p>
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SR305 Bracing ratings for non-proprietary bracing walls
<p>In New Zealand, the wall bracing ratings used for new houses are generally provided by manufacturers based on tests on their proprietary systems to the BRANZ P21 test method. Designers then ensure at each level and in each direction the demand wind or earthquake loads are less than the sum of the resistances of the bracing elements.</p><p>However, when renovating or repairing older buildings, the bracing strength of existing construction is often not known and thus cannot be used in the bracing calculations usually required by the building consent authority.</p><p>This report is intended to provide the bracing ratings of many common bracing walls in older construction to fill this need. Some of the systems tested may be deployed in new construction, and the bracing ratings published herein may therefore be used.</p>
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Ventilation
<p>This stream set out to determine the best ventilation strategy for New Zealand homes.</p>
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Structural testing
<p>BRANZ structural tests demonstrate how building products and systems perform when subjected to external forces. These include earthquakes or strong winds as well as forces associated with normal use, such as occupancy or external vibrations.</p>
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SR260/6 Building Energy End-use Study (BEES) Year 4: Electrical loads
<p>This report presents data and analysis drawn from the Building Energy End-use Study (BEES) detailed monitoring carried out during the 4th year of this 6-year study. This report looks at the variability in electrical usage density and patterns in the premises studied. Understanding the variability in loads is valuable for efficient electrical wiring in buildings and for electricity supply planning.</p><p>One of seven interim reports providing a snapshot of analysis completed to date, the data and analysis in this report contributes to answering research questions 4 to 6. When all data collection has been completed, further analysis will be reported on with the full sample including relationships between end-uses, building types and services.</p>
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SR220 BRANZ test and evaluation method EM3-V3 for bracing rating of walls to NZS 3604
<p>This report presents the basis for changing the current BRANZ test and evaluation procedure used to establish wall bracing ratings. This is known as the BRANZ P21 test method and is used to obtain the bracing ratings of sheet-sheathed timber-framed wall systems for houses and other low-rise structures to meet the wind and seismic demand stipulated in the timber-framed building standard NZS 3604:1999.</p><p>The demand loads in NZS 3604 were based on the loadings specified in the New Zealand loadings standard NZS 4203:1992, but are expected to be revised to be compatible with NZS 1170.5:2004. The revised wind and earthquake test and evaluation method (EM3-V3) was derived from engineering analysis to ensure the as-built house strength from walls assessed by EM3-V3 will achieve the NZS 1170.5 intent in a reliable but economical manner.</p><p>In the EM3-V3 method, the design seismic bracing strength of a test wall is obtained by factoring a selected peak resisted racking load by a two parameters, referred to as F1 and F2. The relationship between F1 and wall deflection was determined by computer simulation, using typical test hysteresis loops, and design level earthquake records. Factor F2 is called the systems factor and was selected to represent the reliable strength enhancement of a total house compared to the sum of the racking strengths of individual bracing walls when isolated from the house and tested separately.</p>