Depends how far away house will be from fence & retaining wall.

Are you wanting solar passive or just natural light, how wide are eaves, glass area, etc. Many things to consider.

Either way aim for smaller but well designed spaces rather than big spaces.

An architect, building designer or a design focussed draftsman is what you're after.

regardless of the height of the retaining wall a 25 square home (about 230 sqm) would leave less than 2.7m deep yard along the northern side and a well designed smaller home set lengthways along the block would maximise external space and northern light but, is the retaining wall along the whole north boundary, is the land on the outside of the retaining wall higher or lower than your side?.... ask council if the fence can include the retaining wall (ie 1m retaining wall plus .8 fence = 1.8 boundary wall?) ...this rough site plan shows how a basic rectangular 25 square building would fit within the block but adding a courtyard could force parts of the house closer to the northern boundary but allow light through courtyard windows deeper into the home..check yourhome.gov for a plan that could suit your block

Thanks guys.

The retaining wall is all along the northern side and full length. Please see the pic.

The land on the other side is at same height as retaining wall. I thought about putting a fence on the wall with .8 height but the corner lot may not be able to comply considering they are a meter high. The developer also stated that their block is flat which means they will remain at that level.

In terms of light we like the sun coming in for winter days hence the reason for thinking about living areas on North.

you could have ceiling height windows on the northern side and use the high fence to create a well shaded outdoor area against the fence not the house but any building designer should be able to include a shadow pattern to show how the sun will enter your new home throughout the year but any fence shouldn't cause any more shading than a neighbouring house providing the house is designed to suit the site

Hi Mic,

Seek out a draftsman or designer who has focus on sustainability and can conduct an Energy rating as part of the design process. A designer who has their Cert Iv in NatHERS is qualified to assess and design for these issues. On a rough calculation - standard WA construction, 25° roof, 500 wide eaves, ceiling at 2.435h then a setback of 1.700 should allow for the sun to strike the floor at equinox, if you have full height windows. Best case scenario place the house between 1.7 to 4m from the fence/retaining. The further it is the more sun strikes the slab during winter. You question about increasing the ceiling height - yes that is a good work around, going to to 3m high may cost more than your think. Another 3c/300mm in height will give you more sun penetration in the winter if your windows are raised and would be a more cost effective solution. But there are many variables such as planning, engineering, buildability and cost. Speak to an qualified designer or architect and they will have the knowledge and experience to deal with all the conflicting factors.