House plans for sloping blocks

Sloping blocks have a reputation for being difficult and expensive when it comes time to bringing house plans to life. However, with the correct approach, a sloping block can offer opportunities that are not possible with a level site.

house plans for sloping blocks

It is important that the house design is specifically developed for the slope of the land, rather than trying to impose a building design that is better suited to a flat site.

Why are sloping blocks traditionally considered difficult to work with?

Sloping blocks tend to receive a lot of bad press. This is usually due to the costs that can be involved in excavation and the construction of retaining walls to build a level platform.

These costs tend to increase when excavation abuts side boundaries, requiring extensive retaining walls along these boundaries. Excavating into the ground also complicates the other building issues such as stormwater drainage, ground water runoff erosion, landscaping difficulties and the opportunity to gain useful outdoor areas.

How does the degree of slope affect house plans?

Sloping blocks will all have different gradient and idiosyncrasies in the layout of the block. Blocks with slight fall may only have 5 degrees across the entire area, whilst blocks on the edge of hills can have over 30 degrees of slope. The quality of the soil and the material composition can also affect house plans. Soft sand may present erosion problems, and on the other end of the spectrum, hard rock may end up increasing the cost of excavation.

How to make the most of a sloping block

Rather than seeing a sloping block as a burden which , try to imagine the potential to create something unique. By developing a house plan from the outset which incorporates changes in level (split level, or multi-storey) the extent of excavation can be minimised or even eliminated. A house supported on columns or piers placed above the ground can also minimise any complications due to groundwater runoff or erosion.

Unlike designing on a level site, the first consideration for a house plan on a sloping site is to develop cross sections through the site which show the slope of the land. These cross sections are developed at the same time as the internal planning of the house is being considered. By working back and forth between the floor plan and the site sections the optimum arrangement for the floor levels of the house can be determined.

Sloping sites can also present other opportunities that are not available on a level site. These opportunities can include:

  • A garage underneath the main floor level of the house
  • Developing an elevated floor level (above street level) to enhance views
  • A more spatially interesting design and layout than a traditional flat block design

In summary, not all sloping sites are difficult and expensive building propositions. While a very steep site will always present particular challenges, many sites with lesser slopes can be successfully developed, resulting in an interesting and unique house, provided the correct design approach is adopted from the outset.

Due to the complications, these sites are best suited to the development of a custom design by an architect. In this way, with the most suitable design, many of the challenges and problems associated with sloping blocks can be eliminated from the outset.

If you, or someone you know, is considering building on a sloping block, contact us and discuss the potential of your site with experienced, qualified architects.