The subject of this website is the house above with 48 solar panels on roof




DESIGN CRITERIA

Introduction

This web page provides an overview of the major design criteria we worked with to pull together a house that met our major objective: to have a very low-cost, comfortable abode that would be stylish but simple and features that would never date.

Readers are requested to keep in mind that the subject house has been specifically designed for the latitude, coastal environment, moderate temperature range and prevailing wind conditions of Bribie Island.


Building Design Overview

The house is built in two wings with a large cross-connecting entrance foyer. The major part of the building, the "main wing", on the southern side of the block is basically a single bedroom house designed to maximise winter sun penetration for warmth, and for summer, to provide shade and encourage airflow for cooling. This separation of the two wings enables us to minimise house cleaning and maintenance. The main living areas have desirable passive solar features and views to the north and east over the wide canal bay.

The "guest wing" (on the northern side of the block) also has passive solar design features but is not as heavily oriented to winter sunshine penetration as the Main Wing. The guest wing comprises two bedrooms, bathroom and laundry. The guest wing is mostly unoccupied and therefore requires little housework or cleaning.

The shed/garage buildings on the western side (away from the canal) provide sufficient room for three cars and a large caravan/motorhome, plus a large workshop area and the renewables energy system plantroom. Access for the caravan is straightforward and direct from the road.

The eastern end of the house overlooks a wide canal that cools the summer breezes and provides a great thermal heat sink in winter.

The major passive solar design principles, building strategies and construction practices we adopted are:

Brief Building Design Criteria

1. The overall aim was to construct a house that did not require cooling in summer or heating in winter, enabled very low maintenance, low or zero costs for electricity and water, extremely comfortable and quiet environment, wheelchair friendly and privacy. Simplicity in design and function was an overriding factor.

2. Correct orientation for both maximum solar gain in winter and minimum direct solar penetration in summer. In addition, the floor plan layout and both internal and external walls are positioned to take advantage of morning and afternoon winter sun angles and penetration, yet exclude morning and late afternoon summer sun penetration.

3. Massive thermal inertia in the concrete slab floors and 300mm thick rammed earth walls.

4. Selectively placed, dark colored, floor tiles on thick, concrete slab, in areas irradiated by winter sunlight (to maximise internal thermal energy absorption and storage).

5. Internal, unobtrusive blinds that can be pulled out of ceiling cavities to cover all glass areas on cool winter nights. External, computer controlled, motorised blinds with 95% UV blockout on the eastern side windows to exclude early morning summer sunlight penetration.

6. The northern wall of the Main Wing is floor to 3.0M high ceiling glass for the full 25 M length (a total of about 75 sq.m) which, coordinated with the roof overhangs, permits sun rays to shine on the part tiled floor during winter. This glass wall has approximately 70% of its area capable of being opened for summer breeze control, comprising regularly spaced floor to ceiling louvres and sliding doors to aid in controlled ventilation. The glazing/door design permits an extensive open environment in the summer period.

7. The southern, rammed earth wall has regularly spaced, very tall, narrow (0.3M), timber louvred windows (each approximately 0.75 square metre) to assist in cross-flow ventilation in summer.

8. The clerestory windows along the full length of the roof top of the Main Wing have double glazed, fixed windows and regularly spaced louvres for promoting summer ventilation. These windows permit winter sun penetration onto the upper section of the southern rammed earth wall for much of the 25 metre length of the main wing of the house. This enables solar energy to be absorbed (internally in the house) for over 8 hours of a mid-winter's day.

9. The clerestory windows, the roof design and roof color selections are an integral part of the thermal air flow design. The aerodynamic features of the roof line and angles encourage gentle breezes through the house in the summer months. In addition a large (1200mm) low-energy slow revving, quiet, roof mounted fan assists ventilation by exhausting above roof line on very hot, windless days.

10. All roof spaces and (non-rammed earth) walls are heavily insulated with materials selected for reduced thermal conduction, reduced radiation heat transfer and noise absorption. The roof space is insulated with R1.5, 50mm bulk insulation/reflective foil blanket immediately under the custom-orb roofing, plus R3.5 bulk insulation batts placed on all ceilings. All hollow (non-rammed earth) walls are filled with R2.5 thermal/sound absorbent insulation batts.

11. The floor most used when standing/walking (the kitchen), and also the "relaxing", (sitting) room, are specially designed Australian Blue Gum timber floors placed on bearers suspended at each end (in a concrete void) to provide a degree of "springiness" to make them comfortable to walk on. The concrete void beneath these floor boards are filled with sound absorbent insulation batts to make them quiet to walk on.

12. All major 240 volt electrical wiring is positioned as far as possible from frequented living areas and sleeping areas. No power wiring outlets are positioned near the bedhead to totally eliminate varying, high level, electromagnetic fields adjacent to the bed. Bedhead lighting is data controlled, remotely switched, remotely transformed, low voltage system to maintain low electrical energy fields near the bed when reading lights are used.

13. All bathroom, toilet, kitchen exhaust and house ventilation is discharged above the roof and not into ceiling space areas.

14. Many of the operating systems throughout the house are designed to be computer controlled by an extremely reliable , dedicated computer system that is capable of being simply programmed and with manual overide facilities



Although many of these design features and systems sound complex, they are completely unobtrusive as they function/operate silently away in the background. Very little knowledge is required to operate these systems and the few maintenance tasks that are occasionally scheduled are simple and easily accomplished by the occupants. If desired, operational modifications are simple and easily managed.


We have enjoyed hearing from visitors who have stayed in this house; they generally make the comment:

'this house sort of runs itself, doesn't it!'






Fred & Jeanette Birkbeck



Email: freddy@feathersnfriends.com.au


Note: Banner at top of page displays an aerial photograph of our passive solar house overlooking a deep-water canal that has direct access to the Pacific Ocean.