Carbon Positive Modular Building

Archiblox recently commissioned eTool to perform another LCA on an innovative modular single apartment. Archiblox demonstrated a conscientious approach to the original design and construction of the building which was evident from the LCA results. With eTool recommendations, notable carbon savings have been achieved with a net carbon positive outcome, which means the building offsets more carbon than it uses in construction and operation.

  • Date: January 2015
  • Architect: Archiblox
  • Location: Victoria

Results Summary

Impact AreaTotal CO2e / Year / occupant (kg CO2e)% Saved Against BenchmarkeTool Medal
Embodied Carbon44071%
Operational Carbon-1,100141%Platinum_medal
Total Carbon-659116%Platinum_medal

Project Features

Low Carbon Structure

The apartment incorporates SIP panels consisting of 2 layers of OSB timber board sandwiched between PIR foam. These low carbon panels are used in floors, walls and roof structure with no need for any other form of structural materials. The purpose of the modular design is that it can be moved as a whole unit to a new site should there be redevelopment pressure in its current site. This ensures a long predicted design life of 105 years. For some perspective, 54 years is the Australian average. Furthermore, the panels themselves are designed for deconstruction, meaning there is a stronger liklihood of them being used in another application at the end of the building’s life.

Increased Functionality

Aside from the increased design life due to the functionality of the building, it has been improved dramtically by incorporating multi-functional furniture. The addition of a number of extra beds allowing for multi-use of rooms has effectively turned a 1 bedroom apartment into a 2.5 bedroom apartment. Ensuring maximum occupancy means the materials that go into the build are shared among more people, making the impacts are lower on a per person basis. Furthermore, the more people that can be housed in a zero carbon dwelling, the fewer that will be living in the average Australian dwelling!

Zero Heating and Cooling

Not only does the building design incorporate solar passive design principles including thermal mass phase change materials, but it will also not be supplied with any form of mechanical cooling or heating equipment. Although many new buildings in Australia are able to provide comfortable living conditions without the need for mechanical equipment, they are rarely be excluded from design specifications due to perceived marketing barriers. This building leads the way in promotes sustainable behavior by encouraging building occupants to address the heat in a more smart and sustainable fashion, rather than relying on harmful fossil fuels.

Low Carbon Finishes

The finishes inside and out are excellent in this design. There is no plasterboard used in the dwelling and features alternatives such as unfinished pine and straw ceiling lining (Solomit). Externally, hardwood timber with no coating applied reduces recurring impacts from re-painting with the timber silvering naturally over time.

Renewable Technologies

A solar hot water system will provide the majority of the occupants hot water requirements with any remainding demand met be an electric boost boiler.

The building incorporates a 5kW PV system, which, renders the building truly carbon neutral (including both embodied and operational emissions). Based on eTool recommendations, the PV will be connected to the grid (as opposed to off-grid) meaning that the extra PV generated during peak hours that is not used within the dwelling is able to be fed into the grid and offset fossil fuel generated electricity. The size of the system is sufficient to offset all operational energy used within the dwelling including electricity that is consumed from the grid when the sun is not shining.

Tree Planting

The opportunity to plant 400 trees will be presented to buyers of the apartment which offsets a total of  66 tonnes of CO2e. This represents 68% of the total embodied life cycle impacts of the building and combined with the net negative energy consumption creates a carbon positive outcome.

This assessment was conducted by  Pat.

Pat Hermon