Building a new home on a slopping block Perth
Whilst some see building on a sloping block a challenge we see it as an opportunity to maximize the potential of the site and your amenity.So, your block slopes, when we think about building a home on a ‘sloping block’ we think about the additional cost and time involved in building a bespoke home on the site.
Obviously, it will need to be a custom home and there will be some additional costs involved in building on a sloping block but it is depending on a lot of factors and with a clever design you can actually turn building on a sloping block into a positive.
This blog will identify different types of sloping blocks and identify ways of value-adding by clever designs.
Sloping blocks that rise from the road.
The easiest sloping block to work with is the block that rises from the road, generally this would involve an under-croft garage or a double and sometime three storey elevation facing the street.
At the sloping block rises the home is matching the slope, so it may be that you have the look and presence of a two-storey home to the street and still have the informal areas transition to the natural ground level at the back of the sloping block.
If your sloping block has views to the front, you can enhance your bespoke home with large balconies across the front of the home.
Some of the challenges on a sloping block that rises from the road include making the entry to the homework, getting sufficient light into the home as the block rises and how to address the retaining walls on the boundary.
Completed Wembley home uses sunken garage retaining to rear, driveway gradient and raised planters to the front to deal with site rising from the road,
Sloping blocks that fall from the road.
Sloping blocks that fall from the road present different opportunities and a lot of the time the value of the block with have an impact on how to address this type of sloping block.
If the value of the block is good, sometimes a clever home design will enhance the value especially if the block has views to the rear.
It may be that home present like a single level home to the street with a relatively flat front yard and as the sloping block falls the home rises from the site so at the rear it may be two or three storeys with balconies set up to maximize the views.
Under construction Mount Pleasant home uses a double storey garage and a bridge to the front door, retaining walls to front, brick build ups and rear and split levels inside the home to deal with a 7000mm slope away from the road.
Some of the challenges of building on a sloping block that falls from the road are the overlooking onto the adjoining properties, building bulk (height and length of wall), retaining walls or build ups and how to get the informal area to relate to the backyard.
Under construction Applecross home uses a rear under-croft, brick build ups to deal with the site that falls from the road and to maximize the rear views.
Sloping blocks that have a cross fall.
When you have a sloping block that has a cross fall it present other rules and is dependant on how much fall, the value of the land and what has been build next door.
Generally sloping blocks with a cross fall either to the LHS or RHS would allow for the lowest part of the front elevation to be used for an under-croft garge this generally assist with the driveway gradient.
The sloping block can also be used to have a split or different level in the home to maximize the natural topography of the site.
Challenges associated with building on a sloping block with a cross fall include wall heights, overlooking retaining walls and the big one costs.
Completed home in Trigg beach features an under-croft garge, retaining walls on the boundary, and cavity filled build ups to deal with this cross-fall site.
Cost associated with building on a sloping block.
the steeper the slope the more challenges it normally presents, and generally more cost associated with building.
A clever home design will be able to maximize the natural topography of the site and value add to the monies spent to build on a sloping site.
Some of the cost associated with building on a sloping site include.
Retaining walls, either on the boundary or on the site, this is a real cost and is dependant on the height and position of the retaining walls as to how much impact it will have on the budget, other considerations with regaining walls are approvals and functionality of the site.
Site work either excavating of the site or importing fill has a big impact on the cost of your site works, this will also be dependant on how big the site is, how much access there is to the site, what’s being built on the adjoining properties along with the type of site it is, i.e., sand, rock or clay etc.
Cavity filled walls or retaining walls under the ground which have a cavity which is filled with concrete and then waterproofed. Not only are they expensive but also add additional time in construction. These can also form brick build ups under the outside wall of the home.
Site access, this will be very dependent on the experience of the builder to map the site and to plan what go where when so as not to have to handle materials manually and ensure the required machinery and vehicles have access to the site.
Steps and ramps that need to be used in the home to provide access down the sides and from the home to the outdoor areas.
Building on or close to the boundary present numerous issues which add cost to the home including removing fences, retaining on the boundary, approvals, overlooking, undermining existing structures, chemical injection, piles, overshadowing adjoining properties.
It is important to carefully consider the various options when building on the boundary.
Time frames generally additional time are associated with building on sloping block, this is because the home need to be built in a certain process and co ordination of the trades are essential.
Designing a New Home for a Sloping Block
Experience is the essential when dealing with complex sites if you haven’t purchased the site it would be a good ideas to catch up on site prior to the purchase to ensure that your expectations can be met with regards budgets, practicality, shire expectations and accommodation.
Once a decision has been made to move forward the first stage is getting a survey of the site with all the levels, heights of retaining walls, heights of fences, and information on an the adjoining properties.
This will allow us to get things right. Things like driveway gradients, overlooking, the amount of retaining on the boundary, overshadowing etc meet strict local council and Australian standards, when building on a sloping site.
As mentioned above, from a purely design point of view, building a home on a sloping block has the huge benefit of allowing you to be much more creative and add more visual interest than homes built on a flat block.
Generally I would use a combination of tools when designing a home on a sloping block this would include retaining walls on the boundary, build ups under the home, splitting the home, retaining on the site, ceiling heights, terracing and tapering the NGL. This way
A lot of sloping blocks offer views giving the designer the opportunity to be creative with your bespoke home. Adding in balconies and/or bridges and large scale windows which integrate into the living areas will help maximise the outlook from these key areas of the home.
Getting the right advice
Sloping blocks will almost certainly require a unique custom designed home be created. Rarely will a standard range, off-the-plan design suffice. So make sure the builder has designers on staff who understand the challenges of building on difficult blocks and are experienced in achieving the most economical design outcome to suit your needs.
Engaging clever home design to design and tender your new bespoke home will ensure you get the best value. we will come up with design solutions that will handle structural issues and design efficiency, while still achieving the bespoke home that works on the site.
More considerations when building your sloped block home in Perth
Cavity filled engineered undercroft walls
Waterproofing of underground walls
Retaining walls
Additional steps downs in the home
Brick build up under the house to allow for level floors
Removal of fencing to allow site access and building on or near boundaries
Undermining your neighbors building which will incur engineering costs and stabilization of soil
Split levels inside the home to allow transitioning to natural ground level outside
Removal or import of additional fill or the ability to store on site.
“A good tip to remember is, if possible, avoid building on the boundaries of your block. This may avoid costs which might include undermining neighbouring structures and fences.”
Things to keep in mind
The key to minimizing construction costs on a sloping block is to reduce the number of earthworks required and reduce the amount and extent of engineered retaining walls.
This can be achieved by using a combination of retaining on the boundary, step-downs inside the home, brick buildups or cavity-filled walls, and careful landscaping.
Designing the right home for your sloping block goes hand in hand with selecting the right person to help you with your home design in Perth.
Experience is the key here, as is taking an imaginative and flexible approach and finding design solutions that others may overlook.
To get started you should get a survey o the property including the adjoining property levels and retaining walls, this will allow the designer to get things right. For example, driveway gradients must meet strict local council and Australian standards, they cannot be too steep and getting the water off the site.
From a purely design point of view, building a home on a sloping block has the opportunity to incorporate higher ceilings can be considered as you work with the land.
Brick build-up under the home with steps inside and outside the home is another design option and can help avoid disrupting the structural integrity of neighboring properties.
A lot of sloping blocks offer views giving the designer the opportunity to be creative. Adding in balconies and/or bridges and large-scale windows, pools that feel like they are sticking out of the ground and which integrate into the living areas.
We also recommend talking with your builder about achieving a passive solar design to keep your energy costs down for heating and cooling the home.
The design concept that you want to achieve and then have them step you through some key considerations, such as the best viewpoints on the block, solar orientation, and prevailing winds.
