Stellaria NZ is excited and proud to present New Zealand's first Porotherm project to be accredited with Homestar. This Taupo project is well underway now. With a lot of planning and careful consideration, the home is being built for a European family who understands the importance of living in a safe, durable and self-sufficient home.
The home is being constructed using Porotherm R25 Th+ (R-value 1.7) and plastered with coloured lime plaster for the interior and lime base with mineral paint for the exterior. The joinery is Passive House certified triple glazed uPVC/Aluminium (R-value 1.6) in dark grey both sides. Solar shading is added with the ability to add fly-screen at a later date. The interior and exterior flooring is natural travertine stone.
The foundation is formed using Cupolex plus an additional thermal underlay with an R-value of 2. Ex-energy slab edge insulation provides added insulation where thermal bridges are likely to occur. Using these few simple elements — clay blocks, good joinery and thermal underlay, this house will have the ability to perform well below passive house energy requirements at just 7kWh/a. The Passive House requirement is 15kWh/a and an average timber frame 200m² home requires 123kWh/a.
The m² cost to use these elements is comparable to a high-end timber frame home but will provide significant cost savings with near-zero energy and maintenance requirements. The home will not require any mechanical ventilation, heat pumps, air conditioning units or air exchange devices due to the natural breathability of the clay and lime walls and top ventilating joinery for night summer cooling. The quality of the materials and simple construction system means this home will virtually run itself.
Lime plasters have the ability to clean and freshen indoor air being antiseptic by nature. No condensation will occur on the windows and due to the moisture management of Porotherm, no moisture will be held in the walls as the block is designed to ‘breathe’ with the lime while the heat and cool takes 12 hours to move across the wall.
A lot of thought has gone into the design and orientation on the section to maximise solar energy with the addition of ground-mounted solar panels. Solar hot water and grey water management as well as water harvesting. Minimal heating is required due to the high performance of the walls and joinery, so a few well-placed infra-red panel heaters will be placed on the walls. Stellaria estimates only three will be required, but more can be added if necessary.
Porotherm is Declare accredited; any waste can be crushed and put back into the grounds. The landscape will be developed with edible gardens in mind — fruits and vegetables. To offset the carbon footprint in the transportation of the clay blocks from Europe, Stellaria NZ Ltd commits to planting 10 specimen or native trees of the clients’ choice.
The family will live here with their two grown children sharing in the design development and construction ensuring their home is well future-proofed for many generations beyond themselves. Porotherm Clay Block construction is about building globally proven sustainable, durable homes of the highest quality and performance level.