Impact stacks need private capital to reach their full potential

Australia’s biggest social challenges don’t lack capital, they lack capital that can be structured to work. 

Housing affordability, financial exclusion, community infrastructure, disability services and the transition to a more equitable economy all require significant investment. Yet many of these challenges sit in parts of the market where capital struggles tp flow at the scale communities need.  

That is why impact stacks matter. 

In our previous articles, we explored the concept of impact stacks and the important role governments and philanthropy can play in creating the conditions and taking the initial risk for them to succeed. But public and charitable funding alone cannot meet the scale of investment required. If impact stacks are to fulfil their potential, private capital must be part of the solution. 

What do we mean by impact stacks? 

An impact stack is the intentional combination of different forms of capital to achieve a shared social outcome. 

Rather than relying on a single funding source or financial instrument, impact stacks bring together complementary participants – governments, philanthropy and private investors – each contributing according to their role, strengths and risk appetite. 

This is not multiple funders working in parallel, it is capital working in sequence and in structure. 

The result is a structure that can unlock opportunities that would otherwise remain out of reach. 

For impact-led organisations, this means access to the finance, support and partnerships they need to grow sustainably. For investors, it creates pathways to deploy capital into opportunities that generate measurable social outcomes alongside financial returns. 

Most importantly, impact stacks recognise that no single organisation or sector can solve complex social challenges alone. 

Why private capital matters 

Private capital brings more than funding. 

It plays a distinct role in the stack, not just providing funding, but bringing the discipline, structuring and the ability to mobilise resources quickly when opportunities emerge and to a scale that works 

Many impact-led organisations have strong business models, deep community relationships and proven outcomes. What they often lack is access to appropriately structured capital that reflects both their commercial realities and their social purpose. 

Private investors can help bridge that gap. 

Where government creates the enabling conditions and philanthropy plays the catalytic, pioneering role - taking early risk- private capital brings what makes impact sustainable at scale: assessment frameworks, standardisation, economies of scale, risk management discipline and governance expectations. It is the layer that enables replication and growth. 

By participating in impact stacks, investors can help expand the pool of available capital, strengthen organisational resilience and enable proven solutions to reach more communities. Their involvement can also signal confidence to other market participants such as banks and institutional funders, encouraging further investment, partnership and market development. 

Importantly, impact stacks create opportunities to align different forms of capital rather than asking any single participant to carry all the risk. This makes investment possible in areas that may otherwise remain underserved despite their social importance. 

What this looks like in practice 

At Sefa, we have seen firsthand how partnerships between private capital and impact-led organisations can unlock meaningful outcomes: once our support had proven the business model of Nightingale Housing, Sydney Retreat and MiHaven they were able to access institutional funding from banks and superfunds to keep growing. 

Since 2011, we have helped unlock more than $160 million in impact finance, supporting organisations working across health, housing, employment, education and community services, with almost $110m contributed by private capital. 

This has been made possible through collaboration with banks, institutional investors, foundations, family offices and other partners who recognise the value of deploying capital with purpose. 

This is a meaningful contribution, but it represents only a fraction of the capital that could be deployed. Australian superannuation funds alone manage over $4 trillion in assets, and high-net-worth investors and wealth advisors control hundreds of billions more.

If the right opportunities and structures exist, the supply of private capital available to back social impact is almost limitless. 

The constraint is not capital - it is whether we can build enough investable opportunities to deploy it. 

When flexible finance is combined with tailored support, organisations gain the confidence, readiness and resilience to grow.  We see this most clearly in sectors like affordable housing and disability services, where the right capital structures allow organisations to move beyond grant dependency into sustainable growth models. Closing that gap is the work ahead. 

The next chapter 

Australia does not have a shortage of organisations creating impact. What we need is stronger backbone infrastructure to help capital reach them effectively. 

Impact stacks provide that architecture. 

For private capital, the opportunity is not simply to fund social outcomes. It is to help build the structures that make those outcomes scalable, sustainable and investable over the long term.  

This is something public and philanthropic funding alone cannot do - once a model is proven and the path to impact and financial sustainability is clear, private capital is what powers replication and expansion. It is the layer of the stack that takes a single successful site or program and helps it reach communities across the country. 

The challenges ahead are too significant for any one impact capital layer  to address alone. 

But together, through thoughtfully designed impact stacks, we can unlock more capital, strengthen more organisations and do more good for communities across Australia. 

Sefa is actively working with private capital to build and scale impact stacks, creating clear pathways to deploy capital into opportunities that deliver meaningful social outcomes at scale. If you’re looking to be part of that, we’d welcome a conversation.