A couple of years ago, before the Real Lettings Property Fund had raised any significant capital, we were nevertheless confident it could illustrate how a standard investment vehicle, with an innovative idea, could provide both a market led financial return and a measurable social impact. In our case, this meant helping people trapped in London's temporary housing problem, just one step from sleeping on its streets, find somewhere to call home.

We just needed the money prove it.

Now, with c£57M raised and 270 homes acquired so far, 430 people have moved into a safe and secure tenancy and RLPF has won a host of awards from both the "sustainable/impact" and "mainstream" sectors in the process; most recently the PRS Initiative of the Year at the Estates Gazette/MIPIM UK Awards in October.

But "social impact" as a decision making or evaluation tool no longer resides merely in the "social investment" arena. With a growing list of success stories it makes ever deeper inroads in to the decision making norms of more mainstream investment institutions as part of the ESG programme.

To that end, here are 9 fundamentals of impact investing relevant to every day business:

1) Social impact measurement results are useful for clearly and concisely conveying a message: they are the adjectives of your story.

2) Social impact measurement is a tool: own it, never let it own you. The transition from tool to master is a subtle one.

3) At their root, every social impact measurement activity should address how the impact is being delivered and what the scope and scale of delivery is.

4) Quality social impact measurement is not always easy so don’t be afraid to experiment.

5) Social impact measurement is not the only arena with the challenge of intangible quantities: beneath the surface, financial metrics are awash with intangible, qualitative assumptions; losing touch with this was a major contributor to the recent financial crisis.

6) Social impact measurement is vital because, in truth, monetary value is only worth its social context: social value defines monetary value, not the other way around.

7) The development of widely applicable social impact metrics will benefit all organisation types: short term “poor” financial metrics do not equate to a “poor” business.

8) To thrive, social impact measurement needs a high level of leadership buy in and an enthusiastic, demand led requirement for change. Top down, bottom up.

9) Social impact measurement needs some element of standardisation in order to gain widespread credibility and acceptance - which will only come from increased trial, error and application. At which point, we will need regular reminding of Point 2!