26 Apr CASE STUDY | Stevens Street, Fremantle
Designed and built by Custom Green, the Stevens Street residence will bring together style and clever passive solar and energy efficient solutions on a modest budget.
About the Client – Our Brief
Custom Green was approached by our clients in February 2016 with a brief to design a small 2 bedroom, 2 bathroom, and 2-storey passive solar home with a modest budget. Their kids, now grown up, had moved out and it was time to downsize.
The Challenges & The Solutions
The block – a small subdivided lot on a gentle slope with sandy soil. Given the location near Fremantle, there were pockets of cap rock onsite which needed to be overcome.
Passive solar design, insulation, thermal mass & materials selection – Custom Green is committed to actively pursuing sustainable practices and applies innovative thinking to the way we design and develop eco homes in our communities. To this end, we have chosen mainstream, cost-effective materials such as a concrete slab on ground with insulated double brickwork to all of the ground floor external walls. The thermal mass will help offset heat gain in summer and heat loss in winter. The upper floor will be constructed using timber frame work, the suspended floor will be sound insulated, and the external walls will have R2.5 batt insulation. Breezes will help cool the thermal mass on the ground floor as well as flush the upper floor loft space of any heat that slowly accumulates throughout the day during Perth’s hot summers.
Glazing will be kept minimal on the eastern and western elevations and we have nominated Low-E glass here for protection. Single, clear glass will be used for the northern aspect of the living to maximise the solar ingress in winter. The living area north glazing will be protected internally by ceiling to floor drapes located behind a ceiling mounted pelmet. Timber decking will feed out and into the rear yard from the dining and living areas, merging the outdoor and the indoor spaces, and also helping minimise heat radiating from the ground, and through the glass, into the living area during summer.
The door linking the hallway and living will have a significant bearing on the home’s passive solar performance as it isolates the stairwell from the living space. Keeping the door closed in winter will prevent heat disappearing up the stairs, whilst keeping the door open in summer will help flush the heat up and out through the windows on the upper floor.
Our cities are experiencing localised warming due to a lack of trees and large amounts of paved and dark-coloured surfaces, which has led to the so-called ‘urban heat island’ effect. With this in mind, the Stevens Street property has been designed with a steel roof cover instead of tiles. Just like a clay pot keeps baking after it has been taken out of the oven, a tiled roof will continue to radiate heat hours after the sun has set! The steel roof cover will cool down as soon as the sun sets, instead of adding heat load to the roof volume and the surrounds as a tiled roof would. We have nominated R4.0 ceiling insulation in the roof as well as Anticon under the roof cover for extra protection. A roof garden above Bedroom 2, located next to the balcony and facing the street, will be a valuable and attractive feature of the home.
Water sensitive design – a rainwater tank will feed the laundry and WC’s. A grey water system will irrigate the garden as well as potentially the roof top garden throughout the year via a subsurface drip irrigation system. Water will be collected and recycled from the laundry, showers and vanities.
Energy efficiency – a photo voltaic system with a storage battery will be added to the roof in the future. For water heating, a heat pump will be installed due to limited roof space.
Transport – given the property’s location is only 200m from a bus station, a single carport and adjoining bicycle storage has been included in the design rather than the usual 2 car garage we tend to see facing the streets.
Universal access – the home has been designed with recessed door sills as well as wider doors and passageways in strategical locations which will allow for independent living as our client’s age.
Health & wellbeing – consideration has been given to minimise VOC off-gassing by using low to no VOC paints and furnishings, to create a healthy living environment. Floors in the hallway and living areas will be kept as bare, lightly polished and sealed concrete floors. A productive garden will be designed to help protect the home against the harsh summer sun as well as provide seasonal vegetables, herbs and fruits for the kitchen.
The owners of Stevens Street came to us with a strong purpose and sound knowledge of sustainable living. Custom Green’s focus is to provide a year-round comfortable home that our clients will love living in. Of course, the wine fridge included in the design will no doubt help!
The design and planning of this innovative home has been an enjoyable process for everyone involved, and together with the client’s knowledge and decisiveness, we aim to have them moved in by Christmas 2017.
For advice on how to get started on your sustainable dream home, contact the Custom Green team on (08) 9479 6828.