Designing Affordable, Innovative, and Sustainable Homes using Prescriptive Building Codes

Introduction

I think it’s fair to say that building codes in many countries are one of the biggest limiting factors impeding progress in the building industry. Their directives often don’t accommodate more advanced, efficient, or sustainable building systems and practices. These older methods, in many cases, have seen little change for more than a century, and they continue to shape our supply chain, manufacturing capabilities, and how we live. They also rely on labour-intensive practices – something that’s getting harder to resource and pay for as time goes on.

Updating Our Building Codes

One of the main challenges with many building codes is that they’re hard and slow to change. Any new revision can have wide-ranging consequences for both the industry and the councils administering them, and that complexity leads to uncertainty or misinterpretation. We also struggle at times to communicate the pros and cons of proposed changes – why they’re necessary, what the benefits and potential drawbacks might be, and how they can be implemented correctly.

Then there’s the flip side, where updates intended to improve buildings unintentionally create new problems or costs, which leads to corners being cut elsewhere.

But we shouldn’t forget that many of these codes developed over time to uphold public safety and structural integrity – key goals that shouldn’t be compromised. As a result, there can be real tension between the safety-first, risk-averse approach of traditional building codes and the desire to rapidly adopt innovative methods or materials. It’s the unknowing that kills progress – even if that technology has been used for decades elsewhere successfully. Layer on new environmental and climate policies, and it’s no wonder code changes sometimes move at a glacial pace.

Risk-Aversion in Finance and Insurance

Complicating matters further, many insurers and bankers worry about the risks of building methods or materials that haven’t been used in their territory at scale. The challenge here is that almost everyone in the banking sector is completely oblivious to how a house is built. I would go as far as to say that most have never played with Lego.

I was dumbfounded when I interviewed two sustainability managers from two New Zealand based high street banks in 2024 – in fact I couldn’t publish the findings as they were so clueless. This was a prime example that greenwashing is alive and well. Oh, did I mention that they really didn’t understand sustainability either. I’m sorry if I’m being rude, but I was deeply disappointed. I even offered to help educate them on the basics for free – an offer they declined due to their extensive workload aparently. I think it must be me that’s the problem – which could be the case – round hole, square peg!

As a result, even when codes are updated, insurance companies or banks might be reluctant to fund or insure projects that use unfamiliar building systems to them.

Even if the systems are approved and in use in Germany say, the cross-border logistics may also mean funding is rejected. This can dampen enthusiasm for innovation, even if the building code itself doesn’t forbid it.

this was a prime example that greenwashing is alive and well

Potential Solutions (and Small Steps Forward)

From my experience, the simplest way to spark change is to either simplify what we already have – or adopt newer, thoroughly tested solutions that allow for more flexibility.

Not every country is at the same level – some are years ahead in their approach to building, and some are decades behind. I believe it would be interesting to look at places like Germany, Austria, or Finland (to name but a few), where housing costs remain more stable, energy efficiency is often higher, and advanced building systems (like mass timber) are more common. Perhaps a handful of pilot projects could be done under a parallel set of building guidelines or through special approval processes, to gauge the true benefits and challenges.

To be fair, managing off-site construction and factory inspections would require a cultural shift. Instead of numerous site inspections, the focus would shift to manufacturing quality control, which in many ways can be more straightforward and efficient. But it does take time for councils, contractors, and lenders alike to adjust to such a shift.

In Defence of Our Current Building Codes

Despite the difficulties, some existing building codes do offer benefits. They are intended to keep people safe by setting a baseline for structural integrity, protection, and sometimes basic health standards.

Ensuring that we still encourage affordable housing, though, means we need to make everything more efficient – both on-site and off-site. We need greater collaboration between all trades at the outset of the project, and in particular designers need to focus on building optimization and affordability before aesthetics whenever possible.

If we fail to produce affordable homes at scale, the global building industry could face real existential challenges.

(See my previous article “How Can Designers be Drivers of Truly Affordable Housing?” for more on design optimization.)

Building Code Litigation

In some countries, like New Zealand, the councils take on a role that leaves them exposed to liability when a build fails. And when it goes wrong the litigation is usually very expensive, and very costly to us, the taxpayers.

In my experience, it might help to push more of that responsibility onto engineers and builders themselves – those who actually produce and certify the structure. This approach could free councils to act more as facilitators and less as potential scapegoats. We could then deskill and reduce our dependence on the councils – and save our ratepayers exorbitant council rates bills and consent fees/contributions.

The Social Impact of Unaffordable Housing

Of course, there’s also a social dimension here: when building codes (along with other factors) make it hard or expensive to build modestly priced homes, first-time buyers in particular bear the brunt. They struggle to afford what’s on the market, developers hesitant to innovate stay with the status quo, and so the cycle continues – producing smaller and smaller houses with less and less basic facilities.

If people can’t afford to buy, housing supply can stagnate – with developers gravitating toward higher-end projects that are more profitable. Ultimately, we need building codes that protect and empower citizens, not just prolong outdated practices that play into the hands of our monopolistic supply chain.

Too Many Cooks Spoil the Broth

I’m writing this article to provoke thought and spark some momentum toward solutions, rather than offering any one definitive fix. We’ve seen countless policies come and go, often dying on the vine because they didn’t fully address how our industry – and its lenders – truly operate.

In my mind, designing and building an affordable house doesn’t have to be complicated. But once too many players, rules, and administrative hurdles get added into the mix, costs rise and projects slow down.

Recommendations To Help You Through the Building Code

Below are some practical steps to help designers, builders, and planners to try and incorporate more efficient building systems under existing codes:

Building Efficiency Drives Affordability

The biggest way to save cost in your building project is to reduce your resources and waste. Choose products and building systems that can achieve more with less. For example, you can choose structural systems like mass timber that can also be the finished internal wall, floor, or roof lining. Even though they are more expensive as single items, they’re replacing many other materials and products – and importantly installation time and cost.

Yes, you may have some challenges if your building code doesn’t accommodate mass timber products – but ask a friendly senior building consents team member what you need to do to persuade them that your building system is fit for purpose.

Explore Alternative Compliance Paths

Some building codes allow a “performance” path in addition to the standard “prescriptive” method. Investigate whether you can meet or exceed code requirements through energy modelling, structural analysis, or other measurable performance criteria. Sometimes product certifications and testing results can be used in your country to gain approvals.

Engage Authorities Early

Involve local building officials or code consultants in the design phase. Getting feedback early can clarify what documentation is needed for alternative materials or methods, reducing approval delays. Sometimes these meetings are free, so well worth asking the question early than experiencing delays later with requests for more information.

Collaborate with Engineers and Builders

Bring structural engineers and specialized builders into your design team from the start. They’ll help you with your innovative design – whether it’s off-site construction, mass timber, or something else – navigate critical safety and performance building standards.

Educate Insurance and Lending Partners (Long shot)

I put this one in for fun – Present case studies, data, and third-party certifications that reinforce the reliability of new methods or materials. Banks and insurers might listen to evidence that supports a less conventional construction approach and potential funding.

Use Standardized Components Where Possible

Even if you’re trying something new (like panelised walls or modular units), design them around widely available material dimensions or standard building practices. This approach can reduce complexity and make code compliance more straightforward.

Focus on Cost-Effective Efficiency

Some products and installation processes are actually so specialised that the supplier themselves does the install. This can even mean that you don’t need site inspections or added approvals – and they can certify their own work. So when researching products ask the supplier why you should use their products over alternatives.

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