Nelligen Hemp Studio

Photo: Nicole Martin

Location:

Nelligen, NSW South Coast

Type of Build:

Two storey studio on rural block.

Owner:

Nicole Martin

Designer:

Nicole Martin

Builder:

Nicole Martin, Owner Builder

Size :

107m²  total; 63m² downstairs and 54m² upstairs loft.

Cost:

Est $200,000

Date of construction:

 April 2012 – est September 2015

Purpose of Build:

An artist’s studio. 

Choice of Material:

Nicole was interested in natural building materials for environmental and health reasons. She also wanted to build the studio herself and wanted the build to be low tech and manageable for an owner builder. Nicole looked into building with straw bales but was worried about vermin and that the width of the walls took up a lot of the floor space. She also looked into building with cob but decided that the material was too heavy to work with on the sloped location. Nicole found hemp through research on natural building techniques, hemp ticked all the boxes. It met the fire regulations, is resistant to termites, lightweight, environmentally responsible, able to be self built and provided a healthy breathable building. 

Nearing completion       Photo: Nicole Martin

Climate:

Zone 6 – Mild Temperate

Local Council:

Eurobodalla Council

Obtaining Approval:

No issue with Council as the build used a regular frame, met the fire code and BASIX, which were the issues that Council was concerned about. Nicole submitted the plans to Council with information about the hemp wall fire resistance and insulation value and no questions were asked about hemp.

Construction:

Nicole carried out the build as owner builder. She worked with a builder on site for 8 weeks to put up the frame, recycled posts and beams,  and the roof and rafters. A crane was brought in to put the large recycled wharf timbers in place. Nicole carried out the remainder of the build herself, except for the plumbing and electrical, with some help from friends and family.

Footings:

The concrete slab is half on ground and half suspended. The suspended slab is supported on a steel reinforced concrete filled concrete block wall on a concrete strip footing on concrete piers. 

Floor:

The ground floor is a concrete slab with ¼ strength black oxide.  The upper storey floor uses recycled  140mm Tasmanian Oak timber from a warehouse in Victoria.

Frame:

Partly large recycled Turpentine wharf timber posts and beams from the CSR factory in Sydney, and partly standard timber frame made off site at Lawmans Frame and Truss in Moruya. The upper floor joists are mixed hardwood from recycled telegraph poles.

Walls:

300mm hemp walls using AHMC (Australian Hemp Masonry Company) binder, with part of the east wall 500mm thick (due to a design change as this wall was originally going to be faced in stone). The walls are finished internally and externally with AHMC hemp lime render, applied in one coat about 10mm thick. No colour was added to the render and it has taken on the colour of the sand.

Under construction

Windows:

Locally made double glazed timber windows and glass doors. The windows have timber sills and storm mouldings ontop attached to the exposed timber lintels. The side window revels are rendered up to the window frame. Internal window reveals are rendered. Fibre cement permanent formwork was installed around the windows and doors.  

Ceiling:

Upstairs Gyprock; downstairs exposed bottom of upstairs recycled Turpentine floorboards.

Roof:

Corrugated Colorbond roofing in Windspray, over foil backed blanket sarking/insulation, with R3.5 sheep’s wool insulation between the rafters.   

Heating:

Nectre wood heater.   

Cooling:

The building uses only natural ventilation with the openable skylights drawing heat out of the house by convection.

Wall construction:

The walls construction was carried out by Nicole with help from friends and family, using a 120L electric pan mixer hired from a friend. Nicole gained experience helping a friend build their hemp walls.

Formwork:

Recycled OSB (oriented strand board). The frame was placed inside the hemp walls but was offset from the centre so that there would be deep window reveals on the inside. The inside walls were 150mm from the frame and the longest bugle batten screws were 150mm. To overcome this Nicole attached blocks of timber to the frame to attach the formwork to. With different sized gaps the use of spacers was awkward and Nicole abandoned them in favour of putting up the formwork using a level to space the formwork. The benefit of this was that there were no spacer holes to fill.

Section Diagram: 

Technical issues:

The offset frame and depth of the wall created issues that were resolved as above. The Gyprock ceiling was time consuming for a novice.The sheet bracing that was required because the building was located in a high wind area, was awkward to place hemp around and on the thin side caused the render to crack.

Advice/Recommendations:

Just do it.
Do not use sheet bracing, if need be find an engineer who can come up with a bracing solution that does not use sheet bracing.

Contact:

Nicole Martin

folkloreandco@outlook.com