Estimated building costs 2005 update

Here is the latest 6-monthly overview of estimated building costs, to July 2005.

Applying for a building consent requires that the estimated value, including GST, be provided for the building work for which the consent is being sought.

Estimated values are used by territorial authorities as a basis for the assessment of the Building Levy. Statistics New Zealand, Quotable Value New Zealand and Building Research also use them.

The estimated values are therefore an important indicator of the level of economic activity.

Using the estimated costs

The Department provides building costs to help territorial authorities arrive at realistic estimated values when they have questioned the job value provided with a consent application.

The application of a realistic cost per square metre for a range of common building types appears to be the soundest method. This approach can be used to establish the estimated cost where there is no better basis, as is likely to occur where no quantity surveyor or similar consultant has been employed. Obviously, if a list or contract price is available, this should be used as the cost of the proposed work.

Costing information

Maltby and Partners Ltd, a firm of construction cost consultants, has provided costing information for a series of building types. Maltby has priced from a set of authentic construction documents in order to establish a unit cost that is as accurate as possible.

The costs for houses are provided for one-off speculative houses. These costs do not reflect the economies that may be gained by builders of group houses, or reflect the additional costs normally associated with architecturally designed houses.

To differentiate, group houses have been assessed as being on average 21 percent cheaper than speculative houses, while architecturally designed houses are assessed as being 20 percent more expensive.

The cost of the speculative house can be used as a base cost on which to establish the cost of group and architecturally designed homes. For example, cost per square metre of small group houses in the Auckland region at July 2000:

• = Auckland base cost less 21%
• = $1,023 - [$1,023 x 21%]
• = $1,023 - $215
• = $808/m2

For all buildings described here, costs include all necessary internal and external finishes to achieve compliance with the Building Code, all services and provision of standard appliances, and site works.

The model has been changed to take into account current changes in the Building Code. These changes have increased costs by approximately 0.5 percent.

Building descriptions

For detailed plans of the following buildings, please refer back to BIA News March 2004 no. 139.

House 145 m²

Single-storey house on a flat site including internal double garage, three bedrooms, open-plan kitchen, dining and lounge, bathroom, separate toilet, en suite, and separate laundry.

Constructed of reinforced concrete slab, timber-framed walls and prefabricated timber-trussed roof, brick veneer external cladding, aluminium external joinery, pre-finished steel roof and plasterboard linings.

House 202 m²

Single-storey house on a flat site including internal double garage, four bedrooms, open-plan kitchen and family room, open-plan dining and lounge, bathroom, separate toilet, en suite, separate dressing room, separate laundry.

Constructed of reinforced concrete slab, timber-framed walls and pre-fabricated timber-trussed roof, brick veneer external cladding, aluminium external joinery, concrete tiled roof, plasterboard linings, and intruder alarm in addition to standard services.

Retirement home 394 m²

Single-storey building on a flat site, including 12 residential bedrooms with washbasins, separate sanitary facilities, dining and lounge, commercial kitchen and laundry, staff accommodation, and office.

Constructed of reinforced concrete slab, timber-framed walls and prefabricated timber-trussed roof, external cladding of fibre-cement with textured coating, aluminium external joinery, pre-finished steel roof, and plasterboard linings.

Light commercial 414 m²

Single-storey warehouse, with mezzanine on a flat site accommodating warehouse, office accommodation, reception and display area, staff lunchroom, kitchen, and toilet facilities.

Constructed of reinforced slab, reinforced concrete columns, tilt-up precast concrete external walls, powder-coated external aluminium joinery, roller shutter doors, factory-painted steel roof, timber-framed internal partitions with painted plasterboard linings.

Commercial (bulk retail) 896 m²

Single-storey building on a flat site with two retail units: one comprising retail area, two offices, kitchen, and toilet facilities; the other containing retail and toilet facilities.

Constructed of reinforced slab, driven timber piles, steel columns, tilt-up precast concrete external walls, powder-coated external aluminium joinery, automatic sliding doors, factory-painted steel roof, timber-framed internal partitions with painted plasterboard linings, suspended ceiling to all but warehouse areas, and steel-framed fire wall between retail units.

Costs and indices of building construction - current July 05 

	Small house		Large house		Industrial building		Bulk retail		Retirement home
Region 1 - Auckland
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,359	1284	$1,204	1247	$1,004	1322	$1,014	1319	$1,632	1221
Jul-05	$1,449	1369	$1,274	1319	$1,074	1414	$1,087	1414	$1,717	1284
Region 2 - waikato BoP
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,332	1273	$1,186	1244	$951	1266	$982	1297	$1,607	1229
Jul-05	$1,426	1363	$1,257	1319	$1,007	1341	$1,050	1387	$1,697	1297
Region 3 - Wellington
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,342	1289	$1,197	1259	$980	1316	$1,004	1352	$1,618	1240
Jul-05	$1,432	1375	$1,264	1330	$1,037	1393	$1,068	1438	$1,702	1304
Region 4 - Remainder of North Island
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,327	1288	$1,183	1249	$945	1293	$966	1320	$1,603	1231
Jul-05	$1,427	1385	$1,261	1332	$1,005	1375	$1,046	1429	$1,696	1303
Region 5 - Canterbury
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,344	1310	$1,187	1269	$972	1337	$995	1368	$1,612	1244
Jul-05	$1,449	1412	$1,269	1357	$1,030	1416	$1,068	1468	$1,716	1324
Region 6 - Remainder of South Island
Date	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index	$/m2	Index
Jan-05	$1,335	1277	$1,191	1246	$960	1289	$982	1315	$1,605	1226
Jul-05	$1,425	1364	$1,262	1320	$1,027	1379	$1,048	1404	$1,691	1292

Disclaimer: The unit construction costs are built up from current commercial prices of materials and labour along with current allowances for contractors' overheads and margins. Pricing is based on a model building for the region and consequently allowances will need to be made where recognition is deemed necessary for particular and specific conditions. The rates per square metre of gross floor area for each building type include an allowance for GST that is applied as a percentage to the final calculated total. The costs are not intended as a definitive cost for actual buildings, and are not to be used for such a purpose.