owner build

The building industry is well versed in volume construction of housing. Provided that the materials and construction methods used are the ones generally used. There are a number of environmental performance limitations of these methods. The following indicators outline the issues:- - kiln fired masonry can mean a one time use of extracted materials to which large energy input has fused the material into its construction unit - these units when applied to external wall surfaces can form a large heat sink where daytime solar heat gain can radiate partially inward into the building during the following night - even with insulation in the inner framed volume, the wall overall heat leak rate is faster than is optimum for winter space warming for comfort - the conventional structure approach is that loosely fixed framing is built and the concrete footing and floor is the rigid element to resist the building movement in respond to soil movement.

In contrast, this architect looks for solutions where:-

  • the building envelope resists solar heat gain through storage in the exterior materials, and optimised insulation the building acts as an integrated semi-monocoque structure with framing rigid fixed and braced in all planes to form an effective structure where less material suffices than in conventional structure
  • the exterior and internal linings (roof deck, ceiling, wall exterior and internal panels) are considered integral to that structure
  • the important parts of the structure are made rigid to the soil movement, but deliberate parts of the structure are made flexible to move with the site without damage to the building
  • this includes wall control joints, floors acting as several independant plates, separation between roof support and wall support, and movement gaps between elements.

The latter approach does not fit easily with conventional construction habit and assumptions. The reaction is to increase the tender price offered on these projects by traditional builders.

Experience shows that the actual construction cost is no greater, when measured in trade by trade construction cost pricing.

Where tenders can not be secured in the acceptable range, on quite a number of the projects from this practice, owner construction has been the acceptable response. This approach brings with it also some further benefits. The 'cost' can be expected to be increased time to construct, and the liklihood that often only one trade will be on-site; obstructing other trades' access for that time.

The demonstrated positives of the owner build approach are:- - the product is precidely what the owner wants - the detailing and construction finish is precisely what the owner wants - the owner as occupant is a more effective operator of the building because of a better knowledge of how it all connects together - the non traditional construction aspects can be achieved by induction of the tradespeople onto the building site.

And most critically, owner build buildings from this practice do NOT exhibit the common construction defects and construction deficiencies which are found in some volume housing, and are the seat of concern by the building surveying community.

Owner build means a mix of:-

  • - construction elements with the owners' direct hands-on contribution
  • - construction elements where the owner sources material and plant for tradespeople to install
  • - construction elements installed by trades supplying labour, plant and materials
  • - the owners' coordination, decisionmaking, planning and financing with and without technical support

This web site cites projects embodying best practice outcomes, and with integrated systems, constructed under owner build processes and contributing to the portfolio of sustainable buildings which show the way for the future.