Summary of Costs A
Element
ELEMENTAL UNIT RATE
B QUANTITY OF THE ELEMENT
C
D
DESCRIPTION
TOTAL COST OF THE ELEMENT
(ELEMENT UNIT)
Measure
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Site Preparation Substructure Frame Structural Walls Upper Floors Roof Exterior Walls & Finish Windows & Exterior Doors Stairs & Balustrades Interior Walls Interior Doors Floor Finishes Wall Finishes Ceiling Finishes Fittings & Fixtures Sanitary Plumbing Heating & Ventilation Fire Services Electrical Services Vertical Transportation Special Services Drainage External Works Sundries SUBTOTAL 25 Preliminaries 26 Margins 27 Contract Contingencies TOTAL
$699 $667 $116 $460 $36 $120 $168 $702 $45 $44 $691 $83 $70 $77 $43 $1,613 $206 $88 $49 $0 $39 $112 $112 $0
47.4 47.4 81.3 27 36.1 45.2 119 44.5 81.3 63.9 3.2 81.3 236.2 81.3 81.3 8 81.3 81.3 81.3 81.3 81.3 81.3 123 81.3
$253,134 $253,134 $253,134
0.10 0.05 0.10
Table 1: Summary of Costs
AxB Lowest Floor Area Lowest Floor Area Gross Floor Area Wall Area Upper Floor Area Flat Roof Area Exterior Wall Area Window/D Area Gross Floor Area Interior Wall Area Number of Doors Floor Finish Area Wall Finish Area Ceiling Finish Area Gross Floor Area Number of Units Gross Floor Area Gross Floor Area Gross Floor Area Gross Floor Area Gross Floor Area Gross Floor Area Net Site Area Gross Floor Area
% % %
$33,152 $31,616 $9,431 $12,420 $1,300 $5,424 $19,992 $31,239 $3,659 $2,812 $2,211 $6,748 $16,534 $6,260 $3,496 $12,904 $16,748 $7,154 $3,984 $0 $3,171 $9,106 $13,776 $0 $253,134 $25,313 $12,657 $25,313 $316,418
1. Site Preparation All the work required to clear the site of existing structure’s, trees and earth to create a suitable and safe building surface, or platform and to support adjoining structures. All retaining walls not attached to the structure are excluded. A large amount of earth needs to be removed to construct the proposed building in the desired locations as shown in figure 1. This earth cannot be transferred easily from cut to fill, hence needs to be disposed of increasing preparation costs. Temporary sheet piling creates the largest influence in elemental cost, due to the amount of earth needing to be temporarily retained whilst construction begins Figure 1: Bulk Excavation Diagram
Table 2: Site Preparation Estimate
2. Substructure All the work carried out below the lowest floor finish, including foundations, connected retaining walls, structural columns, hard fill beneath the floor slabs, and the concrete floor slabs for both the ground floor and garage floor. Excluded from this element are all site preparation costs, plumbing and drainage costs and excavations above the lowest floor level. The retaining walls shown in blue and the suspended concrete floor slab of the ground floor in green make up the greater portion of the cost in this element. In this design, substructure will have a much larger cost involved due to the complexity and forces involved in creating a recessed garaged beneath the ground floor of the two story house. Figure 2: Substructure Diagram
Table 3: Substructure Estimate
3. Frame Frame is described in the New Zealand Institute of Quantity Surveyors Elemental Analysis of Cost of Building Projects as all load bearing columns, beams and formwork above the lowest floor finish, with emphasis on the roofing membrane. What is interesting about this element and again according to NZIQS the upper floor joists are included under frame and not in Element 5, upper floors. This contradicts Rawlinson’s but I am assuming that the NZIQS recommendation is more accurate. Figure 3 illustrates where the priced elements are in the design. The structure of the roof design has been excluded from this element as the author feels that these items lend themselves more closely to Element 6 Roof.
Figure 3: Frame Diagram
Table 4: Frame Estimate
4. Structural Walls This rate includes only two walls, shown to the right fig 4 and 5. These structural walls retain the cut earth to the south of the building. The southern structural walls of the two story house have been constructed from thick masonry concrete. All applied finishes and treatments to the walls have been excluded from this element. The comparative rate stated in Rawlinson’s that the square metre price for retaining area included all drainage costs associated with water runoff from the site above.
Figure 4: GF Structural Wall
Figure 5: FF Structural Wall
Table 5: Structural Wall Estimate
5. Upper Floors The upper floor consists of all the suspended upper floor and balcony floors, of which this design only has the first. As stated previously this element does not include floor support beams, it simply only includes the particle board which the upper floor finish is applied too.
Figure 6: Upper Floor Diagram
Table 6: Upper Floor Estimate
6. Roof This element prices the waterproof coverings of a roof. The purlins have been added into this element as the design has such a significantly flat roof well below a ten degree pitch. Technically they are not support joists, trusses or rafters as stated in the NZIQS exclusions for this element, so the roof purlins have been assumed to fit this element.
Figure 7: Roof Diagram
Table 7: Roof Estimate
7. Exterior Walls and Finish All work to exterior walls including applied finishes make up this element of the design. The external wall timber frame structure has been included along with the Hardie weatherboard cladding. A deduction has only been made to the external wall area where there are two significantly large windows. The benefits of deducting these areas of the external area will provide more accurate measurement of price, as stated below. It has been assumed that the walls are timber frame and use weatherboard as cladding. Figure 8: GF External Walls
Table 8: External Wall and Finish Estimate
Figure 9: FF External Walls
8. Windows and Exterior Doors This element includes all windows and external doors. The images to the left illustrate the assumed window types and sizes. The original plans failed to dimension a number of the windows so the sizes have been assumed or altered to improve the amount of daylight getting into the space. This has caused for a relatively high elemental unit at 44.5m2 of window and external door area.
Figure 10: GF Windows & Ext Door
Table 9: Windows & External Door Estimate
Figure 11: FF Windows
9. Stairs and Balustrades Flights and intermediate landings including balustrades make up this element. Figure 12 illustrates where the stairs are in relationship to the design. This element does not include stair finishing.
Figure 12: Stair Diagram
Table 10: Stairs & Balustrade Estimate
10. Interior Walls Figure 13 and 14 communicate the locations of the 17 internal walls. This element includes all internal wall structures but does not include wall finishes. The door area has not been deducted from the overall internal wall area, as the labour and waste involved in producing the two doorways will work out to a similar price as if the void was deducted.
Figure 13: GF Internal Walls
Table 11: Internal Wall Estimate
Figure 14: FF Internal Walls
11. Interior Doors All internal doors including frames, finishing, architraves and hardware have been included in this elemental rate. There are only two internal doors in the house, with the two bathrooms requiring privacy. A comparative rate from Rawlinson’s has been used to accurately price the two hardboard doors.
Figure 15: GF Internal Door
Table 12: Internal Door Estimate
Figure 16: FF Internal Door
12. Floor Finishes This element includes all floor finishes, including the stairwell. It has been assumed that the main flooring material used in the design is carpet with tiles used in the bathroom. Simplified area calculations have been used to quickly assess the average floor area of each room.
Figure 17: GF Floor Finish
Table 13: Floor Finish Estimate
13. Wall Finishes This element includes all preparatory work and finishes to the interior walls. The perimeter tool on Revit was used to accurately calculate the internal wall area of each room. It has been assumed that GIB Standard Plasterboard will be used in most areas of the home with Aqualine in the bathrooms and Noiseline in the study area. The images to the right illustrate the assumptions in material changes made. All insulation behind the internal wall finishes was also included in this element as described in the NZIQS guide.
Figure 18: FF Floor Finish
Table 14: Internal Wall Finish Estimate
14. Ceiling Finishes This element includes all preparatory work and finished to the suspended ceilings of the ground and first floor. The images above show where the ceiling area is measured. Ceiling insulation has been included in this rate as well as the battens which the ceiling is fixed too.
Figure 21: GF Ceiling Finish Diagram
Table 15: Ceiling Finish Estimate
Figure 22: FF Ceiling Finish Diagram
15. Fittings and Fixtures This element prices all the built in joinery including hardware and finishes. It has been assumed that all bookshelves, furniture and seating are not fixed to the building and are therefore not included in this rate. It was also very difficult to price the small hot water cupboard door; this fact should be made aware to the client.
Figure 23: GF Fittings & Fixtures
Table 16: Fittings & Fixtures Estimate
16. Sanitary Plumbing This element includes all items such which use the water mains, soil or waste pipes. The locations of these items are shown to the right in figures 24 and 25. The prices have been created using comparative costs and in the case of the hot water cylinder detailed rates. These rates are more design specific than simply using an elemental rate and therefore should provide a more accurate plumbing rate. It has been assumed that the pipe rate is included in the comparative rate of each element.
Figure 24: GF Sanitary Plumbing
Table 17: Sanitary Plumbing Estimate
Figure 25: FF Sanitary Plumbing
17. Heating and Ventilation This rate includes all heating and ventilation equipment in the house design. All of the items below have been assumed to be in the design, none of which have been shown in any of the plans, so a judgment call was made. These items are not essential in providing a liveable home but they can provide a more comfortable home.
Table 18: Heating & Ventilation Estimate
18. Fire Services The design has been assumed to consist of sprinklers and other fire services. This will allow for a dramatic decrease in yearly insurance costs, but the element is merely recommended and will likely not be installed in the building as seven thousand dollars is a lot for fire safety.
Table 19: Fire Services Estimate
19. Electrical Services This element prices the electrical services providing lighting and power to the two story home.
Table 20: Electrical Services Estimate
20. Vertical Transport There is no vertical transport in this design
Table 21: Vertical Transport Estimate: Not Required
21. Special Services The below items have been assumed to fit into this element as they do not readily lend themselves to any of the other elements.
Table 22: Special Services Estimate
22. Drainage This element prices all drainage of waste and water being released out to the main lines. It has been assumed that the distance to these main pipes is twenty metres.
Table 23: Drainage Estimate
23. External Works This element prices all site works beyond the line of the exterior face of the building structure. The drawing to the right illustrates where much of this external works is occurring. Because of the radical change to the site there has needed to be a large amount of external works put in place throughout the site to allow for an extended driveway for more car parking, and a new foot path up to the entrance to the house. The prices of these works are shown below. The net site area has been defined from the top of the driveway up to the top of the stairs on the northern side of the path.
Figure 26: External Works Diagram
Table 24: External Works Estimate
24. Sundries There are no items which need to be priced under this element
Table 25: Sundries Estimate: Not Required
25. Preliminaries This element suggests a percentage of the total cost 10% (As described in Rawlinson’s) to cover all usual preliminary and general items, such as temporary services, plant and equipment, scaffolding, local authority charges etc.
Table 26: Preliminaries Estimate
26. Margins All sums identifiable in a tender to cover cost contributions to the Main contractors profit and overhead costs.
Table 27: Margins Estimate
27. Contingencies All contract contingency sums contained in contract. This price is also to cover uncertainties and unexpected delays, or trouble with the building process. Because of the level of accuracy that the report goes into the contingency for unknowns is relatively low.
Table 28: Contract Contingency Estimate