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Cost comparisons research

In this section you will find information on the costs of building with different timber elements.

Cost comparisons research

NZ Wood comissioned research conducted by BRANZ examined at what slope timber framed floors are more economical than concrete slab floors when a house is on a slope.

 

 

 

 

Base case and Assumptions:
•    8.7m X 17.4m long floor area.
•    Ground slope restricted to less than 19 degrees for timber piles (3m length).  Beyond that poles are used.
•    Rates are from Rawlinsons Construction handbook 2008.
•    Not all materials required are taken into consideration.

Timber floor material details:
•    20mm particleboard.
•    150mm X 75mm, sub floor bearers (4 rows).
•    200mm X 50mm @ 600 centres, ground floor joists (30).
•    125mm X 125mm, Timber piles (48 at variable lengths).
•    100mm X 100mm, sub floor diagonal bracing (4 at variable lengths).
•    M12 X 250mm, bolts for braces (8).
•    200mm X 50mm, solid blocking (26 m).

Concrete Slab floor material details:
•    100mm reinforced concrete slab and thickening.
•    200mm Masonry wall (3 sides at variable area).
•    400mm X 400mm concrete foundational beams (2).
•    400mm X 400mm concrete footings (2 at variable lengths).
•    Crushed rock Hardfill (variable volume).

 

In Auckland when the ground slope is 6 degrees or more, timber frame is the cheaper option

 

In Wellington when the ground slope is 8 degrees or more, timber frame is the cheaper option.

 

 

In Christchurch when the ground slope is 7 degrees or more, timber frame is the cheaper option.

 

In Dunedin when the ground slope is 6 degrees or more, timber frame is the cheaper option

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Cost comparisons research