property:development:construction:costs:home

Property:Development:Construction:Costs

Summary

The following brings together multiple construction costs.

Costs

Groundwork

Summary

Groundwork, grading is done after any demolition of pre-existing structures, and before any foundations. It can involve the creation of retaining walls and grading the soil in preparation for foundations.

Notes

Terms
  • TBD
Recommendations

Gravel is the cheapest driveway material. Asphalt/metal'ed is next, Concrete is getting up there.

Options
  • Driveways:
    • Concrete is at the upper end (even though asphalt is better?). Gravel is the cheapest (actually dirt is).
      • “Gravel driveways are less than half the cost of of a plain concrete driveway”1).
        • But according to this site, it's an even bigger spread:
          • Concrete: $190/m2 (more form work, reinforcement, drainage than other options)
          • Concrete pavers: $60/m2
          • Asphalt: $80-$100/m2 (with edging can really be nice. But only comes in black. Look for ways to create natural breaks?).
          • Tar and Chip: 3rd cheapest option2)
          • Stone: 2nd cheapest option (stone over gravel)3)
          • Gravel: 6/m2 – although this does not line up with with estimator of $40/m24) (but then again it's asphalt price seems to be way off).

        ### Considerations ###

  • TBD
Specifications
  • The ground should be formed for drainage before any gravel is laid down.
Suppliers
  • TBD
Tools

DIY'ers will need to consider the following tools:

  • TBD

Resources

* https://www.zones.co.nz/landscape-design-cost/driveway-options-and-prices * https://wellington.govt.nz/~/media/services/environment-and-waste/urban-development/files/03partb.pdf?la=en

Services

  • Water Supply (3 x 25K litres, installed): $11,0005)
  • Septic system (for 3 bedrooms), installed): $24,0006)

Foundations

  • Slab on Grade is less expensive than crawl-space7) approach (both use a spread footing approach to bearing walls and columns).
  • TBD.
    • Make sure to understand that coordination of electrical and plumbing for kitchen, bathrooms and utility/laundry rooms has to be done up front in order to not have to make changes later.

Walls

Summary

Notes

Terms

* plasterboard: see drywall. * wallboard: see drywall. * sheet rock: see drywall. * gyprock: see drywall. * gypsum board/panel: see drywall. * GIB board: see plasterboard. * Gibraltar board: see drywall. * Drywall: gypsum in between two sheets of paper to make boards for interior wall and ceiling panels, replacing the earlier lath (small wooden slats) and plaster approach. The long edge of the boards are tapered, ready for mud and taping, and the short edge of drwall boards are open/butt edged, meaning that paper tape applied between wall and ceiling cause bumps that need to be covered with molding.

  • Boards in NZ come 10,13,16 by 240, 480, 600 lengths8).

* tapers and mudmen: those who apply tape and mud to the seams of drywall. * mud: see drywall compound. * joint cement: see drywall compound. * drywall compound: a white powder of primarily gypsum dust mixed with water to form a mud the consistency of cake frosting, which is used with paper or fiber joint tape to seal joints between sheets of drywall. Comes as either setting type powder (hardens by chemical change, not evaporation, so does not shrink, so good to fill holes, but sets fast) or ready-mix.

  • Applied in 3 coats: bedding, filler and a top/finish coat. Always use a respirator when sanding, and maybe even applying.

* bedding coat9): the drywall compound coat applied first, in which to push the paper joining tape. A tapping compound (extra sticky) is used. * filler coat10): coat to cover the tape that was pushed into the bedding coat, and then roughly sanded. * top/finish coat11): a fine grain topping compound coat to cover the filler coat, finely sanded to between 0 (rough) and 5 (super fine), before primer then paint is applied. * drywall clips: allow for joining two boards together when there is no backing joists12). * drywall tape13): see bedding and drywall compound. * furring/hat channels: channels applied to level and damp proof the hanging of drywall ceilings14). * Parging: see Skimming. The application of a thin layer of mortar to a wall to cover CMU bricks or defects and provide a finish stucco texture. sanding. You hide the bump using molding. * monolithic claddings: see stucco over mesh, cementboard, 40mm EIFS foam or directly on CMU - as long as it is spaced and vented. * stucco: lime based exterior surfacing.

  • WRB: weather resistant borders (house wrap or felt paper). See vapour barrier.
  • Vapour barrier: Placed in a surface nearest the cold side. In NZ, that means just under the battens/furrings. A slab-on-grade or basement floor should be poured over a cross-laminated polyethylene vapor barrier over 4 inches (10 cm) of granular fill to prevent wicking of moisture from the ground and radon gas incursion.
  • house wrap: has micro pores that does not in bulk water or drafts – while being vapour permeable, to let out moisture.
  • [asphalt] house felt [paper]15): absorbs humidity, pulling it away from joists, etc. But it has to be handled more carefully than house wrap and not left exposed to sunlight in order to not dry out.
  • dimensional lumber16): lumber sawn and planed to standard specific actual sizes (versus their nomimal size).
  • post and beam: the traditional timber framing methodology, now only used for barns.
  • balloon framing: a light [stick] framing construction methodology which replaced the earlier post and beam building methodology, by replacing posts with smaller studs. Differs from current platform framing in that studs would rise up 2 floors from the sill [plate] to the [top] plate. Balloon framing has been made illegal in many places due to the ease in which flames rise through floors.
  • platform framing: the dominant current light timber framing methodology, differing from the earlier balloon framing methodology in each floor is built separately, as a complete platform, complete with its own sill [plate] and [top] plate.
  • bottom plate: see sill plate.
  • sole plate: see sill plate.
  • sill plate: the bottom of a sip or stud wall, on which studs or sip panels sit. MUST be protected from moisture coming up (eg: from concrete pad), by a) attaching it to sub-flooring, or if directly on concrete, by putting down a moisture barrier (construction tape, other) and b) being treated and c) being a distance off grade/soil. Attached to the foundation wall using j-bolts.
  • j-bolt: embedded in the foundation wall on which to attach the sill plate.
  • top plate: caps off a floors studs. Whereas the sill plate only uses a single piece of dimensional lumber, the top plate always uses two ('top plated') to provide greater stability.
  • stud17): vertical framing member in a building's wall of smaller cross section than a post. Braced using dwangs.
  • dwang18): (nogging in AU/GB, blocking (US)) are horizontal bracing pieces used between wall studs or floor joists to give rigidity to the wall or floor frames of a building.
    • cripple stud19): a stud located either above or below a framed opening, that does not run the full height of the wall
    • trimmer stud: see jack stud.
    • jack stud20): stud to the left or right of a window or door, running from the bottom plate to the underside of a lintel or [door/window] header. Note that on the windows edge would be both a cripple (to support the sill) and the jack (to support the plate).
  • window sill21): similar to a wall's [header] plate for the jack studs below the opening (ie, it's top plated in the same way).
  • window header22): similar to a wall's footer for the jack studs above it, except that it is built up (eg: 3 pieces) of multiple pieces, on edge, to provide a stronger bearing for the top jack studs to transfer load to it without flexing or rotation.
  • trimmer:
  • lintel:
  • battens (BE): see furring.
  • strapping (AE): see furring.
  • furring: the leveling out of surfaces, providing a damp/mold isolation in the process23).
  • joist: a horizontal on-end plank used to span open spaces below, transfering loads to beams, which transfer their load down via walls of studs or posts created an assembly of dimensional lumber.
  • toe-nailing: driving a nail at an angle (about 50 degrees) through a board. For example, nailing studs down to a bottom sill plate.
  • face-nailing: driving a nail through two parallel dimensional lumber pieces. For example: when attaching a jack stud to a stud, or face-nailing 3 pieces together to make a lintel/window header, or when top plating a window sill or wall top plate.
  • end-nailing: driving a nail through a board into perpendicular piece behind it. Eg: attaching a lintel to a jack/trimmer stud.
  • LSL: Laminated Strand Lumber. The OSB of beams. Not as strong as LVL24).
  • TJI: Trus Joist® TJI® joists are similar to LSL, but arranged into looking like steal I-beams. Flexes very little. Spans better than timber25).
  • LVL: Laminated Veneer Lumber. Thin, veneer layers to form larger beams and columns. These layers run perpendicular to the load.Stronger than SP8/SP10 grade natural timber. LVL costs run high because of the high degree of manufacturing that goes into each piece.
  • SCL: Structural Composite Lumbar (ie, PSL).
  • PSL: Parrallel Strand Lumber is stronger than LVL, but more expensive than LVL, Glulam. One thing to keep in mind with parallam is that the material swells in wet or humid conditions. Without special manufacturing procedures to minimize it, the swelling can be as much as 8%.
  • Glulam: Full-size pieces of lumber glued together under high pressure to form larger beams and columns. Expensive enough that they should only be used if the beams are to be exposed.
  • Steel: Use only if SCL is not locally available, or the span is really too large for SCL (maybe a redesign is still an option?) because it requires a significant change of scheduling, handling care and attachment effort26).
  • Loads: structures in NZ must be built to 1.5KPa (ie, 1500 N/m^2, ie 150Kg/m^2)27) for live loads (2KPa for decks)28), and rooves above 400m for 1.5KPa. So, basically, whether you designing a roof or interior floor, the span is basically the same.
  • ridge beam: the longitudinal beam at the top (eg: of a gable roof).
  • rafters: diagonal beams running from the wall to the ridge beam (eg: of a gable roof), on which purlins sit (where pidgeons may roost…). Rafters are analogous roof equivalent of a floor's joists29).
  • purlin30): longitudinal beams running parallel to the ridge beam, in between the rafter beams.
  • H3.2: the minimum hazard treatment level for wood exposed to the elements, unpainted, and not exposed to ground (eg: rafters)31).
  • H3.1: the minimum hazard treatment level for wood not exposed to the elements (eg: external painted, or internal studs)32).
  • H5: the minimum hazard treatment level for wood exposed to the elements and ground (eg: piles)33).
Recommendations

Use Property:Development:Construction:Materials:Formance SIP Panels. It adds up to 20% of material cost, but removes the cost of labour in terms of on-site drilling for measuring, cutting, bracing, wiring, insulating.

Options
  • TBD.
Considerations
  • TBD
Specifications

Specifications to keep in mind include:

  • TBD.
Suppliers
  • https://formance.co.nz/
    • Advantages:
      • Cut offsite
      • Faster assembly on site, already with moisture barrier.
        • Just needs battening & external cladding and internal surface treatment (same as all houses). This just replaces the structure.
        • Considerations:
        • 20% more than traditional stick construction.
          • Cost regained in 4 years.
        • Requires ceiling & wall OSBs to be covered with gypsum boards.
        • As well as wood floors directly on OSB (no subflooring required).
        • Can be installed to span foundation beams on a slope.
        • If installing on wood foundations, requires a soffit closure of foundation beams to protect OSB from upblown weather.
        • Thinner panels can be installed directly on concrete pad (warning on crunching, leveling, etc?)

        * Engineers:

    • Formance recommended:
Tools
  • Cutter34)
  • 48" T-Square35)
  • Paper Drywall Tape36) * Inner metal corners
  • Outer metal corners: use
  • Drywall screws: have a slightly concave cone head in order to not tear the paper as pushes in.
Instructions

Resources

Rooves

* G&S stated the following prices/sq.m, admitting they were on the high side to have less surprises:

  • Rooves:
    • Membrane: $130-$150/m2
    • Corrugated Iron: $90-$100/m2 (ColorSteel)
      • Note that is was higher than the 85/m2 that Robin of MetalCraft/Wellington stated.
      • Tip from Jon & G&S Roofing: select 0.55 for a flat roof (thinnest appropriate solution).
  • Walls:
    • Corrugated Iron: 150-170/m2 (ColorSteel)
      • Again, this was higher than the 110-120/m2 that Robin of MetalCraft/Wellington stated.
      • The pricing is higher than walls due to multiple openings and flashing required.
      • Tip from Jon & G&S Roofing: select 0.4 for walls (thinnest appropriate solution).

Trusses

Resources

1)
https://www.homeadvisor.com/cost/garages/gravel-driveway-road/
2) , 3)
https://www.thespruce.com/keep-driveway-cost-low-with-loose-materials-1398334
4)
https://www.zones.co.nz/landscape-design-cost/driveway-options-and-prices
5) , 6)
http://www.thetankguy.co.nz/
7)
https://www.fixr.com/comparisons/slab-vs-crawl-space
8)
https://en.wikipedia.org/wiki/Drywall
9) , 10) , 11)
https://en.wikipedia.org/wiki/Joint_compound
12)
https://www.house-painting-info.com/wp-content/uploads/2014/06/artimg_hyde-bear-claw-repair-clips-in-use2.jpg
13) , 36)
https://www.thespruce.com/rating-the-best-drywall-tapes-4125930
14)
https://www.clarkdietrich.com/products/drywall-framing/furring-channel-hat-channel
15)
https://barricadebp.com/blog/house-wrap-vs-felt-paper-which-is-the-better-wrb/
16)
https://www.thespruce.com/dimensional-lumber-definition-1821735
17) , 19) , 20) , 21)
https://en.wikipedia.org/wiki/Wall_stud
18)
https://en.wikipedia.org/wiki/Dwang
22)
https://en.wikipedia.org/wiki/Wall_plate
23)
https://en.wikipedia.org/wiki/Furring
24)
https://www.nishkian.com/understanding-engineered-wood-beam-options/
25)
http://nzwoodproducts.co.nz/media/products/files/2013/2310_LPSS_-_70T_-_Rafter_Span_Tables_V4_0_2.pdf
26)
https://barton-supply.com/2017/03/06/steel-beams-vs-wood-beams-for-your-residential-building-project/
27) , 28)
https://www.buildmagazine.org.nz/assets/PDF/Build-97-17-LoadsOnDecks.pdf
29)
https://www.hunker.com/12542157/the-difference-between-joists-rafters
30)
https://en.wikipedia.org/wiki/Purlin
31) , 32) , 33)
https://www.weathertight.org.nz/new-buildings/timber-treatment/
34) , 35)
https://www.thespruce.com/easy-way-to-cut-big-drywall-1821492
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