AREndurance STUDY NOTES building design + construction systems CONTENT AREA: PRINCIPLES Building Design Facts/Rules: • After an idea is developed for a building, an architect helps consolidate the owner’s thoughts and designs the form of the building. They assemble a group of engineers and specialists to help work out the details and scheme for the building. • Drawings and specifications are produced to explain how and what the building will be made of. • A contractor is hired either by negotiation or bid, who then hires subcontractors to complete specific portions of the work (e.g.: casework, electrical, doors/hardware) • Drawings/spec are submitted to the necessary municipality (city or county, typically) who verifies conformance with building code and local requirements/ordinances. • The building inspector and design team should observe the work at regular intervals to verify compliance with the construction documents. Concepts/Goals: • Designers are able to use a limitless palate of materials and systems to produce a building of any desired form/texture • Designers are bound by physical limitations (e.g.: size of site, soil bearing capacity, maximum span), budget, and legal restrictions. • Design professionals need to have a broad understanding of people, climate, physical principles of materials, available technologies, legal restrictions, and contractual arrangements and obligations under which buildings are built. • Designers must answer several questions when designing a building: • What will give the required functional performance? • What will give the desired aesthetic result? • What is possible legally? • What is most economic? • How can we build in a sustainable manner? Design Principles + Design Impact on Human Behavior Vocabulary: • Ahwahnee principles: a collective vision of how urban and suburban planning should follow certain fundamental principles regarding community size, integration, transportation, open space, pedestrian paths, native vegetation, water and energy use. Facts/Rules: • Typical Human Comfort Zone !Winter!!!!!=!63°F - 71°F !Summer!!!!=!66°F - 75°F !Tolerable humidity!!!= !30% - 60% !Uncomfortable humidity !!= !+ 75% page 1 of 105 :: created 09.2012 :: are 4.0 :: organized by twitter/areforum member @jennypdx AREndurance STUDY NOTES building design + construction systems • Winds !Basic Speed!!!!= !70 - 80 miles/hour !Unnoticeable!!!!= !< 50 feet/minute !Pleasant!!!!=!50 - 100 feet/minute !Pleasant *and* noticeable!!=!100 - 200 feet/minute !Drafty !!!!!= !200 - 300 feet/minute !Uncomfortable!! ! ! =!+ 300 feet/minute !Pressure varies as the square of the velocity (if velocity doubles, pressure quadruples) • Pedestrian Circulation !Area of a person!!!= !3 sf !Easy movement !!!=!13 sf !Crowd movement !!!= !7 sf !No movement !! ! ! = !3 sf !Sidewalks !!!!= !5’-0” wide min !Collector walks !!!=!6-0” - 10’-0” wide min • Noise !Smallest difference in 2 sounds the human ear can detect is 1 decibel !Sleeping, studying, whispering!=!30 decibels !Conversation, comfort!! ! =!50 - 60 decibels !Safety Threshold!!!= !85 decibels !Rock Band!!!!!=!90 - 100 decibels • Trees thin out high frequency noises • Each increase of 10 decibels the human ear perceives as 10x loud. • Typically doubling the distance between source and ear reduces level by 6 decibels • On freeways, doubling the distance between source and ear reduce level by 3 decibels • Winds add “white noise” that blurs any one sound frequency. • Walls close to a noise source reduce high frequency, but midway between the source and the ear does nothing. Concepts/Goals: • The best thing we can do as architects is to get involved in the art and business of buildings. We must learn how materials feel in the hand, how they look installed, how they're manufactured, worked, and put in place, how the perform, and how the they deteriorate over time. Processes: • Address Human Elements • Senses: sight, sound, smell and touch give an impression of size, shape, and material. Taste probably isn’t an issue...unless you’ve got willy wonka walls :) • Style: follow conventional and acceptable solutions to maintain consistency and harmony within space and surrounding context • Culture: different cultures use buildings differently (separation of women/men, sanitary standards, layout of spaces for rituals, feng shui, vastu shastra, etc.) • Address building organizational values • Behavioral Interests: desired spaces to perform tasks • Circulation: ease of movement around site and building • Health: reduce stressors (noise, crowding, sun glare, sick building syndrome) • Adaptability: allow for future changes, modifications, and flexibility • Cost: use regular forms, plans, and compact arrangements page 2 of 105 :: created 09.2012 :: are 4.0 :: organized by twitter/areforum member @jennypdx AREndurance STUDY NOTES building design + construction systems • Design principles that increase personal safety in public areas • Design for the needs of the local residents to encourage a well used space. • Concentrate activities in a limited number of areas • Promote foot traffic by providing shortcuts/inviting features to encourage new routes • Visible into public space and evening lighting • Protected play area for small kids with comfortable seating for parents Building Systems + Their Integration Vocabulary: • Post: long, sturdy piece of timber or metal set upright in the ground used to support • Beam: a member that supports loads perpendicularly to its longitudinal axis • Simple Beam: rests on a support at each end and ends are free to rotate • Cantilever Beam: supported at one end and restrained from rotation at that end • Overhanging Beam: rests on 2+ supports and has one or both ends cantilevered beyond the support • Fixed End Beam: fixed against rotation at both ends • Frame: a structural system that supports other components of a physical construction • Truss: a framework, typically consisting of rafters, posts, and struts, supporting a roof, bridge, or other structure • Gage line: standard dimension from corner edge of an angle to centerline of bolt holes. depends on size of angle • Arch: a curved symmetrical structure spanning an opening and typically supporting the weight of a bridge, roof, or wall above it. Facts/Rules: • The physical properties of of the four common structural materials help determine the appropriate building system to use Material Allowable Allowable Density Modulus of Tensile Compressive Elasticity Strength Strength Wood 700 psi 1,100 psi 30 pcf 1,200,000 psi Brick Masonry 0 psi 250 psi 120 pcf 1,200,000 psi Steel 22,000 psi 22,000 psi 490 pcf 29,000,000 psi Concrete 0 psi 1,350 psi 145 pcf 3,150,000 psi • Wood (See Materials + Technology Content Area for more in-depth notes) • The oldest and most common system • One way structural system (load is transmitted through members in one direction) ! page 3 of 105 :: created 09.2012 :: are 4.0 :: organized by twitter/areforum member @jennypdx AREndurance STUDY NOTES building design + construction systems Type Width Spacing Spans Top/Bottom Use Advantage Joists 2” nom 12” or 16” 20’ to 25’ Bridging supports Between Tried and true o.c. bottom edge, beams or method sheathing holds top bearing walls in place I-Joist 1-3/4” to 12” - 24” 8’ to 24’ 9-1/2” - 16” depth Residential/ Efficient strl shape 3-1/2” o.c. OSB webs and light as shop fabrication microllam (thick commercial eliminates common plywood) flanges defects connect to wall with hangers Glulam 3-1/8”, varies 15’ to 60’ Several layers of Columns and can be left exposed, 5-1/8”, timber bonded beams, can be tapered or 6-3/4”, together with glue commercial, curved 8-3/4” and connected with public plates and/or bolts Plank/ 4” or 6” 4’ or 6’ or 8’ 10’ to 20’ Wood decking span Between Easy to insulate Beam between beams, girders or Framing underside finish bearing walls, ceiling residential Truss varies 24” o.c. 24’ to 40’ 12 - 36” depth made Residential, MEP can pass thru of strand wood Commercial, members connected Public with plates Box Up to 30” varies 50’ Plywood panels Residential, Looks like solid Beam glued & nailed to 2x4 Commercial, timber, custom Public made • Steel (See Materials + Technology Content Area for more in-depth notes) • Most commonly used structural material due to its high strength, availability, adaptability, ductility (can deform and return to original shape/bends before it breaks) • Suited for multi-floor construction due to strength and structural continuity • Beams span shorter distances of 8’ - 10’ • Girders span longer distances of 25’ - 40’ • Concrete (See Materials + Technology Content Area for more in-depth notes) • Cast-in-place concrete: typically involves steel reinforcement (rebar), sometime post-tensioning is used • Precast structural members: high-strength steel cables are pre-stressed/stretched and concrete is poured on top. When concrete reaches minimum allowable strength cables are cut from formwork and compressive stresses are transferred to concrete that resists tension forces of own weight/live load • Post-tensioned concrete: steel tendons are laid out in desired direction and concrete is poured on top. When concrete is cured tendons are tensioned and force is transferred to the concrete through end anchorages. • Beam & Girder system: • Large girders carry intermediate beams which support slabs with spans of 15’-30’ • Easy to form and construct making it economical page 4 of 105 :: created 09.2012 :: are 4.0 :: organized by twitter/areforum member @jennypdx AREndurance STUDY NOTES building design + construction systems