SLOPING BLOCK HOUSE DESIGN SPECIALISTS

Sloping sites offer the canvas for some of the most beautiful, awe inspiring, architectural homes across Australia.

| RISE HOUSE | PRETTY BEACH, CENTRAL COAST NSW. BY FBC ARCHITECTS

1. SLOPING SITES: BACKGROUND

Some of Australia’s most interesting and beautiful homes are built on sloping sites; perched upon a hillside capturing panoramic city views, nestled amongst bushland overlooking distant valleys or smack bang on the shores of a sparkling beachfront or waterway.

Although not exclusively Australian, the sloping site home has definitely won a place in the heart and minds of many Australians. Along the east coast of Australia, particularly in areas like Sydney's Eastern Suburbs, North Shore and Northern Beaches / Central Coast / Newcastle, the undulating topography results in many sites being categorised as 'sloping sites' meaning those wanting to build a home in these areas will require site specific design solutions.

| FLOW HOUSE | DEE WHY, NORTHERN BEACHES SYDNEY. BY FBC ARCHITECTS

Building on a sloping site offers many advantages;

opportunities for soaring views, a sense of height and distance
capturing desirable breezes
a feeling of retreat and tranquility - living amongst the treetops

However, to realise the full design potential of these advantages you need to temper the constraints too.

A few key items to balance:

Realising site potential and maximising site benefits, whilst minimising site drawbacks
Engineering / buildability considerations
Managing costs
Maximise accessibility (day-to-day practicality / useability)
Minimising environmental and visual impacts

Every site has its own unique set of characteristics, opportunities and constraints, so every site needs to be considered individually – there’s no ‘apply all’ method when it comes to these sites, like the uniqueness of each site a custom home should compliment it. Having a professional involved from the outset is crucial to ensure the home is an inspiring place to reside but also to ensure the practicality of day-to-day living and most importantly can actually be realised when it comes down to construction cost vs your budget.

FBC Architects are the sloping block house design specialists and can assist you every step of the way, from initial feasibility / concepts, approvals, selecting a builder / costings and on-site inspections during construction. We work with a team of highly reputable consultants and builders to offer a complete solution and guide you through every step.

| DRIFT HOUSE | NORTH CURL CURL, NORTHERN BEACHES SYDNEY. BY FBC ARCHITECTS

2. SITE TYPES

Image Credit: Gold Coast Council

Sloping Blocks can generally be categorised into four main types:

FLAT TO SLIGHT SLOPE

Slope 0 – 7%: Single slab on ground construction is only suitable for a site slope up to 7%

Slope 7-10%: Should accommodate some level change within the building footprint i.e split floor levels

MODERATE SLOPE

Slope 10-20%: stepping two or more slabs or using part suspended floor is recommended

STEEP SLOPE

Slope 20-33%: Post and beam suspended floor construction should be considered which steps with the site. This may include a lower part level of concrete slab

EXTREME SLOPE

Slope 33%+: Suspended or pole construction techniques are required. This degree of slope is better suited to a downslope configuration as driveway access is generally very difficult on upslope lots, requiring large batters/retaining walls and sometimes a curving driveway and /or a garage significantly detached from the main dwelling near street level

3. TIPS

GENERAL TIPS

Work with the slope don’t ‘fight it’, split level /suspended floor designs that have wider floor plates (rather than depth) usually work better with the sloping terrain
Get a good design & consultant team together early to avoid surprises later i.e architect / designer, bushfire consultant, geotechnical engineer, builder. Your architect / designer will often be able to organise and co-ordinate the team
Avoid ‘cookie cutter’ designs which have been specifically designed for a flat block
Single slab on ground construction is only appropriate up to a slope of 7% as the cut/fill/retaining required beyond this becomes excessive (you may still have one floor of a multi-storey home as slab on ground)
Additional costs on sloping sites can include excavation, piling, retaining walls, additional engineering, increased labour costs. To reduce costs generally try to reduce the amount of cut and retaining required - 'touch the earth lightly' and reduce the weight of the building
Offset additional construction costs by reducing the amount of floor area you are building, think ‘quality not quantity’
Generally lighter weight / framed buildings are more practical / cost effective in these environments, supporting suspended concrete slabs & using heavier masonry construction can become cost prohibitive and present some signifcant engineering issues
Minimise site clearing and protect mature vegetation which assists with slope stability

TIPS FOR UP-SLOPE SITES

Land slopes (rises) up from road
Provide a balcony over the garage which can reduce visual dominance of the garage from the street and provide a dual use of the already constructed platform
Aim for a level transition from elevated living areas to the backyard
Your eaves are going to be on display more than any other house / block type, consider making a feature of these with interesting linings or exposed / tapered eave profiles, conversely your roof sheeting is not going to be readily visible (in most scenarios) so consider reducing expenditure here.

TIPS FOR DOWN-SLOPE SITES

Land slopes away from road
Suits suspended structural systems
Locate garages or carports close to street to maximise efficiency of vehicle access
Provide level entry off the street into the living areas, for easy accessibility day-to-day
Avoid extra storey at the rear which can significantly increase the building height and bulk from the rear. Excessively increasing a buildings height may make it difficult to obtain from development consent from council