Architect and sustainable housing expert Ben Caine cautions homeowners about various pitfalls to consider when choosing an architect or designer to deliver their new home or renovation.

Architects currently design less than 5% of Australian homes, but with the imperative of climate emergency – and the fact that residential buildings are responsible for around 24% of overall electricity use and 12 percent of total carbon emissions in Australia – moves are afoot to improve design and performance standards going forward.

Did you know that Australians build roughly 200,000 new homes each year, and there are approximately 8 million existing homes that will require deep retrofitting to remain comfortable and improve energy efficiency?

Architects are at the forefront of this transformation to a low-carbon built environment, and while there are some great architects around Australia producing very considered work, many of the architectural homes that are most visible –– the houses that are published in magazines and that win awards – are a far cry from what’s practical, cost effective, energy efficient or even fit-for-purpose.

And these highly visible and celebrated homes may actually alienate some potential clients from considering working with an architect, because they often perpetuate the myth that architecture is expensive and unattainable.

Why do architects tend to focus on high-end housing?

Architects and designers tend to prioritise working for high-end / high budget clients because those projects generate higher architecture fees, and allow architects to unleash their creative design skills.

In order to attract these high-end clients, architects need their work to win awards and be widely published, because being highly visible helps to build their reputation in the marketplace. Most magazine editors prefer highly bespoke and unusual homes that make compelling content for their readers; they are not so focussed on whether the design elements are practical or affordable for readers (and potential future clients).

Similarly, architecture and design awards juries usually tend adopt the same mindset – the focus is on unusual, bespoke, highly detailed, high-end and eye-catching projects. Add to this the fact that most juries are made up of architects, with the occasional journalist – who is unlikely to have design or construction knowledge, or a sense of what’s practical or costeffective.

Some argue that architectural homes at the cutting edge of design provide a worthy benchmark for the industry to follow, but these projects often suffer from lengthy time frames, comparably high costs of design and construction, added complexity and elevated risk. All of these factors prevent these highly bespoke, one-off projects from positively impacting or influencing the home design and construction industry at large.

All of this results in architects becoming effectively locked into a design “arms race”, to stay ahead of the competition in a bid to attract and win their future clients.

So what’s the downside for consumers?

This type of architecture often ignores the clients’ intended patterns of use and practical concerns; it fails to adequately address thermal and functional performance; it ignores both upfront and ongoing financial considerations; and sometimes it fails to provide even basic comfort and durability.

Recently in Australia, we’ve seen several highly awarded and widely published residential projects by well-known architects that feature design and construction elements that we consider to be the “7 Deadly Sins” of residential building design.

We’re spelling out these seven deadly sins to inform and caution new home clients and renovators, and to provide pointers and benchmarks to guide their design and construction decisions, so they can avoid these pitfalls in their future projects.

1. Highly specific floorplans

In magazines, it’s common to see homes with impractical and inflexible room dimensions and layouts. An example is a suburban villa with just one bedroom that opens directly to the main living space, which may be suitable for the original occupants – an architect – but which provides little flexibility or privacy for future occupants.

We’ve also seen kitchens that only have enough space for one person at a time, and sprawling family homes that have little or no useable outdoor play space. These floorplan issues are problematic because buildings tend to outlive their original owners by many years, or even decades. So, for sustainability’s sake, new homes and renovations should be designed to accommodate a range of different occupants and configurations, with the ability to easily change function and use over the projected lifespan of the building.

2. Ignoring Building Science

Lately we’ve been hearing from owners of architect-designed homes who’ve found themselves disappointed with the thermal performance and year-round comfort levels of their new homes. In some cases, those owners are considering selling up their architect-designed homes to start again with Leanhaus, because we prioritise thermal performance and efficiency – and occupant health and well-being – in every project we undertake.

These stories make us wonder: “How can this situation arise, when there is so much building science knowledge available in the industry today?”

The answer appears to be that very few architects or designers currently have the necessary skills – or inclination – to model, test and optimise the building science and expected performance of their designs.

This is evident when we look at highly celebrated homes in awards and magazines: we see some very obvious issues around orientation, glazing, shading, moisture management and thermal bridging, all of which will have a dramatic impact on the way the house performs throughout the seasons.

One of the reasons this isn’t the case, currently, is because the Nationwide House Energy Rating Scheme (NatHERS) is a minimum standard tool, not a high benchmark for performance. So homes with low performance can still be NatHERS certified. As a result, many designers don’t need to prioritise efficient design, instead they choose to install expensive and energy-intensive systems such as heated flooring or large air conditioning systems to achieve internal temperature control.

On top of this, the energy rating is most frequently outsourced to an energy assessor, whose primary task is to provide a minimum compliance certificate. If this rating process is outsourced late in the design process, the architect/designer is disconnected from a detailed understanding of how their proposed design decisions affect building performance outcomes, and they are unlikely to learn from their mistakes.

At Leanhaus, we believe that building performance, comfort and energy efficiency should be at the forefront of new home design, and that architects should have the skills to scientifically optimise any and all buildings that they design. We use building science to inform the planning and design from the outset, and we are constantly learning more about how to improve performance, comfort and health for our clients.

seven deadly sins residential architecture

3. Excessive use of steel structure

Steel – in the form of columns and beams that are used to create expansive rooms and spaces – is often the first choice of architects and engineers looking to achieve dramatic overhangs and wide openings.

But steel is a carbon-intensive building product that comes at significant cost to the project in terms of time, money and energy efficiency, not to mention it’s negative effects on the climate. At Leanhaus, we work hard to avoid the use of steel because it introduces multiple speciality construction steps, with significant implications for cost and time factors, whilst offering minimal benefit to our clients.

Some of the additional requirements of building with steel include engineering design and detailing, builder estimating and procurement of steel fabrication, detailed shop drawings (designed, drafted and triple checked), delivery and cranage, site welding and installation. Also, steel is difficult to modify on site if the design changes; or if it’s the wrong size; or is in the way of essential services like ductwork.

What’s more, even though steel is often buried in the structure and is not visible in the end result, it acts as a good conductor of heat and can create thermal bridges by bringing external heat deep into the building. These thermal bridges have the potential to seriously compromise the energy efficiency of a new home, and they can cause condensation which can lead to mould issues if the steel is not properly isolated and insulated.

Instead of steel, we prefer to construct our housing projects with a combination of materials that are readily available, easily understood by builders and tradespeople, and that result in buildings that are comfortable and healthy, and durable and low-maintenance, for decades to come.

seven deadly sins residential architecture

4. Concrete roofs, balconies and awnings

Concrete has many of the same issues as steel: it’s very high in embodied carbon and is also thermally conductive. Despite this, we’ve seen a growing trend in residential architecture towards concrete roofs, awnings and projections.

These have the potential to create significant problems around water tightness and insulation, and if concrete protrudes beyond the building’s edges, it provides a thermal bridge, which leaks internal warmth in winter and heats up the home’s interiors in summer.

Concrete roof gardens are particularly problematic, and must be very carefully designed, detailed and constructed to have any hope of being leak free, and to prevent condensation from thermal bridging.

An award-winning architect conceded that his concrete roof terrace did in fact leak, despite numerous construction measures and membranes to prevent leaks. Roof leaks through concrete are costly to repair, and can lead to concrete cancer, which reduces the overall lifespan of the building.

Leaks can also cause mould – which is expensive to identify and eradicate – and which can lead to sick building syndrome as well as cause health issues in the people who live there. I wouldn’t wish this on anyone, and for these reasons, we don’t use concrete for anything other than floor slabs, where the benefits of using the material far outweigh the potential risks.

seven deadly sins residential architecture

5. Internal box gutter and terraces over living spaces

A fundamental objective of building design is to create shelter, but this basic objective is often overlooked by designers in pursuit of eye-catching aesthetics. A common example is the use of box gutters – which are often built over internal living spaces to achieve flat roofs – or terraces without visible gutters. Gutters play an important role in building design because they temporarily collect rainwater and direct it away from the building via downpipes.

Box gutters or roof terraces will invariably leak at some point due to unpredictable storms, faulty workmanship, poor design, or maintenance issues. And box gutters differ from standard gutters in that even a minor leak will result in water entering the building and potentially causing significant damage.

Unfortunately, this was evidenced in Perth when a large hailstorm hit the city in 2010. A deluge of hail filled the gutters and prevented rainwater from being shed from buildings. As a result, box gutters overflowed back into the roof space, causing collapsed ceilings and water damage. An insurer recollected to me that there wasn’t a box gutter in Perth that survived that storm.

For peace of mind that lasts long after a home has been built, we make sure our roof designs shed water outside the building envelope and detail our construction for multiple fail-safes, in case a single layer of the building envelope ever fail.

6. Impractical materials and finishes

A guaranteed way for a new residential architecture project to stand out from the crowd is to use unusual materials and finishes, or to use common utilitarian materials in inventive ways that are sometimes intended to make a project appear ‘affordable’.

The main problem with this is that utilitarian building products such as concrete blocks, oriented strand board (OSB), fibre cement and extruded bricks are intended to be hidden. Architects like to use these low-cost products and reinvent how they’re installed, for example, using OSB for cabinetry or wall linings, or concrete blocks laid in atypical patterns.

These products are usually manufactured without consistent dimensions, making installation time-consuming and wasteful. And the tradespeople tasked with installing these products are usually expected to quickly erect them, rather than to install them in a detailed way with care and precision.

These products also don’t have the surface finishes, so they need to be properly sealed to prevent staining, volatile compound off-gassing and the build-up of dust, which adds to the time and cost associated with their use.

In addition, commercial products intended for large buildings are often unfamiliar to residential tradespeople and builders, so require the use of commercial sub-contractors to install them. Unfortunately, these tradespeople aren’t used to servicing small jobs and have to inflate their pricing to cover their overheads, risk and time.

New and unfamiliar products come with inherent risks relating to procurement, installation, warranties and performance. It requires great care to ensure they don’t add unreasonable costs, delays or risks to the project and client’s bottom line.

We believe there’s nothing worse than installing cheap products in an expensive way, because the end result is a low-quality product, often poorly detailed, that lacks the durability and longevity of alternatives. For that reason, we argue that it’s much better to choose quality products that are straightforward and cost-effective to install, and that will last for decades.

7. Complex construction detailing

Complicated or novel construction details can sometimes enhance a project, but in many cases, the client and architect don’t fully understand the additional cost that may arise from their use. Builders and tradespeople have their tried-and-tested methods of achieving good and reliable construction details, and it often demands additional time, cost and risk to dramatically deviate from these.

We find that complexity in design often results from the architects’ lack of construction experience and rigour in the early phases of the project. The unintended costs of complexity sometimes means that important home features such as external shading and solar PV need to be forgone to deliver the project on budget.

We are fully supportive of architects being creative and innovative, but detailed design should be considered and intentional with respect to the overall building’s aims and the clients’ budget, desires and values.

Where to from here?

In closing, we encourage homeowners and renovators to be on the lookout for the 7 Deadly Sins of residential architecture next time they read a magazine, view a home tour online, review a list of award-winning buildings, or go looking for inspiration for their upcoming design and build project.

To recap, the seven deadly sins are:

Highly specific floorplans
Ignoring building science
Excessive use of steel structure
Concrete roofs, balconies and awnings.
Internal box gutter and terraces over living spaces
Impractical materials and finishes, and
Complex construction detailing

Some highly-regarded projects feature just one or two of these sins; some unfortunately can tick off all seven.

So if your architect proposes to incorporate any of these Deadly Sins into your new home, ask them to justify the additional time, cost and risk involved, or better still, ask them to provide alternatives that will potentially save you money and improve your quality of life, without causing unnecessary stress and ongoing problems once you move into your home.

This article was written by Ben Caine, architect and Founder of Leanhaus.

Architecture & Design Team

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