This week saw DTZ and Colliers International at the heart of potentially game-changing deals for the agency market.

Colliers’ purchase of niche London office and investment firm H2SO this week is a good fit. Colliers is in aggressive growth mode and needs to bulk up in the golden goose market that is central London.

And for the partners of H2SO, it is undoubtedly a decent pay day and allows them access to more global clients obsessed with the capital.

Most interestingly, the sale of H2SO is the first of a generation of gutsy firms that set up at the bottom around five years ago. Everything is easy in hindsight but taking the move of fleeing the corporate nest to an “eat what you kill” model was a brave one that many talked about, but only a few did. The bold calls made by those firms are now paying off in a booming market.

The time is now ripe for more deals of this kind. Top 10 agency firms are desperate to get a bigger piece of the pie, and with them making good money rather than having to worry about costs, they can splash the cash to tempt top niche companies in. For firms being bought, they too can demand a better price, generated off decent performance figures from the last year or two.

How quickly times have changed. When big hitters from the likes of H2SO, Dowley Turner Real Estate and Hanover Green set up around 2009, often having sold their previous businesses to the firms they were leaving, the word on the street was that this was the end of big firms paying lots of money for little ones.

It was too costly, integration was too difficult and it was more efficient to pick off the best people or grow organically rather than buy a business. That has turned out to be false, but for the leaders of those firms chasing market share, the perils of mergers and acquisitions should be at the forefront of their minds. To work, corporate acquisitions have to be in it for the long term, not just the boom times. These deals should only be done if they will still make good sense if the market cools off or even tanks.

The clichés of integration and cultural fit are difficult to truly grasp but they are crucial to making corporate acquisitions work. Getting clear the intentions of the protagonists in the firm that is being bought from the outset is imperative. Horror stories of those being bought and sitting in silos in their new firm, waiting for golden handcuffs to be unlocked should never be repeated.

There is a plethora of top niche firms out there that would strengthen many of the big players, but buyers must not forget the dangers and pitfalls amidst their desperate search for growth.

DTZ watch

Growth will also be the buzz word for DTZ when its private equity-backed takeover completes in September.

The appointment of former CBRE chief and M&A expert Brett White — who has been there, seen it and done it in terms of building a global giant — is a massive statement of its intentions. Its new owners also have eye-watering amounts of equity for the project.

Expect to finally see a big purchase in the US, which could revolutionise its deal-flow between there and Asia, to be top of the to-do list. Many firms have talked over the years of breaking the global duopoly CBRE enjoys with JLL, but this is the most serious chance yet of it actually happening.