According to TechCrunch, Tenaya Capital led the round and additional investors include Sequoia, Founders Fund, YC Continuity and Northgate. Today's investment brings the total to over $58 million.

PlanGrid CEO Tracy Young says they took the money, even though most of the Series A remains in the bank, because customers have been demanding they add new functionality to the product. The money should help beef up the development team to do that.

'Our users are only beginning to see what's possible and asking us for [additional ways to use] this tool,' she said.

Specifically, they are asking PlanGrid to digitize other aspects of the construction process that remain primarily on paper such as change orders, field notes, inspection reports and any paper generated around the project that is not tracked as of yet in the core product.

The company has had great success selling the core product reporting that they have worked on 300,000 construction projects worldwide and managing an astonishing 30 million blueprints. Young says even though the sales team is based in the US, there are construction projects using PlanGrid in every developed in the country in the world.

PlanGrid was born of the idea that construction blueprints were too hard to maintain in paper form. Every time the plan changed, it was a challenge to keep up -- and plans tend to change rapidly on a construction project. People have created work-around systems on the massive paper documents like using colored sticky notes to track different types of changes, but these solutions were band-aids at best.

What PlanGrid did was marry cloud-based file storage with software on the iPad. In 2011 when they came up with the idea, it was a pretty radical notion to put a business tool on the iPad, which most people considered a consumer device at the time.

The company operated for its first several years using money from its seed round and profits from selling the product -- imagine that -- before accepting a Series A round last year. At that point the company took off, growing from just 30 people to 180 today. The company plans to expand to 300 or 350 employees by the end of next year completing a period of remarkably rapid growth.

Managing Growth

Over the last year or so, the company has had to completely transform, and the money they spent from the Series A round went to operationalizing what had been a very small company. That meant going from a company that was using primarily Google Docs to run the company to putting a number of tools in place including Slack for communication, NetSuite for finance, Salesforce for customer management and Hubspot for marketing.

Young says they are obsessive when it comes to thinking about policy and they work to make sure the policies they put out are in simple language and easy to implement. The company has two all-hands and two town meetings a month to explain what's happening and keep employees abreast of any changes in policy or procedure.

All new employees go through a week long boot camp where they learn about the construction industry, the company and the product. At the end the training period, they have a company-wide graduation where graduates are given a PlanGrid hard hat.

The company has been spread out over a couple of buildings because of the rapid expansion, but the plan is to be in a single building by January.