Clever Thinking And Innovative Solutions

Strachan Group Architects This small project is unique in many ways, including the project team consisting
of Dave Strachan, in conjunction with 16 third year Unitec architecture students, John Cocks and Marshall Cook. This team not only designed the Onemana Bach, they built it.

Designed and built at Unitec, Auckland and transported to the coastal town of Onemana, this small project is more than meets the eye. Whilst it was small in both budget and footprint, clever thinking and innovative solutions have produced a bach that ticks all the boxes; the clients, Andrew and Shiree Morrison “couldn’t be happier.” They did not want a large, elaborate beach house, nor would their budget allow for it. They wanted a well designed, compact, stylish yet simple easy care place to go with their two girls.

With a budget of $120K and a total footprint of only 100m2 (75m2 interior + 25m2 covered decks) Onemana Bach offers a master bedroom with private deck, bunkroom, bathroom/ laundry with both interior and exterior access, kitchen, living, dining with decks to both the East and West and built in furniture and storage throughout.

A number of design decisions have elevated a simple building to a project which is full of interest and rich in character; A key move is the timber slatted breezeway which penetrates the high performance thermal envelope, running North East South West, this assists with natural cross ventilation and highlights the play of light with the late afternoon sun filtering through the trees and timber slatting. Designing for a tight build
time and with the intention of transportation had its challenges and set parameters for the project. Plywood interiors give a warmth and casual nature to the spaces, fitting for a New Zealand bach, as well as providing some extra bracing for the building’s three hour journey to Onemana. One of the building’s stand out features is the experimental use of a Metalcraft Thermospan EPS roofing system, not frequently used in the residential context. By combining structure, cladding, and insulation all–in-one, this Structurally Insulated Panel was a great solution; it was both competitive on price and offered savings in terms of labour and time. It also offers almost double the thermal efficiency required by the NZ Building Code. From arrival onsite in 6 panels, each 15.5 metres long, the complete installation took only 4-5 hours. A standard
trapezoidal profiled cladding, of a matching colour, was used to wrap the roof down the South wall, making the roof a distinct architectural element. The custom gutter, designed specifically to work with the thickness of the roof panel, further strengthens the appearance of the roof as a singular element, rather than a build up of individual components.

The building also includes a take on traditional board and batten, offering rhythm and relief and double floor
step works with the natural contours of the site. The North Eastern corner hovers above the slope with large timber doors peeling back to open the corner; and the material palette is largely locally sourced, boasting timber throughout including decking inside and out, slatted ceilings and privacy screens and plywood on both walls and ceilings.

Clients: Andrew and Shiree Morrison

Architects: Strachan Group Architects
Telephone: 09 638 6302
With Marshall Cook of
Cook Sargisson & Pirie
Sixteen 3rd year Unitec School of
Architecture Students

Main Contractors: Dave Strachan
John Cocks
With sixteen 3rd year Unitec School
of Architecture Students

Roofing Manufacturer: Metalcraft Insulated Panel Systems
(Metecno Ltd)

Roofing: 150mm Thermospan EPS Maxx

Colour: Colorsteel ®Foam Maxx

Roofing Installer: Unitec Students

Gutter and flashings: Pacific Roofing

Photographer: Simon Devitt
(all photos except ‘the team’ &
craning roof into place which were
provided by SGA)