They found themselves on the outskirts of Paris, renovating a 300-year-old house, which had been a shoe repair shop.
Seth's brother Izaak travelled from Britain to help with the project, which Seth said was very different from New Zealand building because of different building materials that had to be breathable, such as lime plasters with clay and lime paints.
By coincidence BuildersCrack has a Hawke's Bay co-founder, Jeremy Wyn-Harris.
He grew up on a Takapau farm and went to Takapau Primary and Central Hawkes Bay College before gaining a masters degrees in electrical engineering from the University of Canterbury.
BuildersCrack wasn't his first startup. A former company manufactured an internet camera in Sydney, selling 10,000 units in the United States and Singapore.
After five years the business failed.
"It had good potential but we had issues with our business partners," he said.
The North Carolina partners were "problematic".
He then worked for a Christchurch company when "I was told that somebody had a great idea" after fruitlessly searching for a home-improvement tradesperson.
"The very next day we heard from a friend who also thought it was a great idea."
"The idea wasn't actually mine but I guess I was there on day two, about nine years ago."
Of the BuildersCrack founders he is the "operational owner", working in the business for two years.
It is not a long way from his electrical engineering background - he does a lot of software development.
"My first job was software - I have been doing software for a very long time and to be honest most people that do electrical engineering, probably about half of them end up with jobs in software because that's where the jobs are."
More than 2000 tradespeople have signed up to BuildersCrack and 50,000 homeowners offered at least one job "and many have offered much more".
He said growth had been 50 per cent annually over several years and employs eight people in Canterbury and Auckland.
Its public profile has also lifted. It was used by contestants on TV's The Block to select tradespeople in 2013 and 2015. Last year it was used by Our First Home contestants.
Once jobs to be done are lodged with the website, a company algorithm selects which tradespeople can contact the person offering the job.
"We send email leads and also push notifications through our mobile app for tradespeople.
"We have three or four tradespeople chasing a job. The homeowner goes through our website and looks at all of the reviews in the profile and the accreditation - to see if they are a licensed building practitioner or registered plumber electrician, etc. We double-check all the government licensing authorities for that."
The parties exchange contact information and site visits are made, with an online quote facility available.
"At the very end of the process we ask for a review. The homeowner can rank their workmanship, their schedule, cost, professionalism."
He said the integrity of the ranking system was why BuildersCrack was steadily growing.
"You can only review a tradesperson who has shown an interest, so it is very, very difficult to anyone to do a staged review.
"It is a very powerful - you just can't review anybody, it has to be a two-way thing.
"Our 65,000 reviews are genuine. I don't know of any other industry that can boast that."
Mr Wyn-Harris said he enjoys start-ups, but being established has its advantages.
"There is something about taking an idea that is fresh with unlimited potential, before you have thought about all that could stop it working.
"Sometimes it's quite nice to have an established business which you can just grow."
He said the company had added value to its networking model - the chasing and quoting process is protected by patent - and new features are helping acceptance.
"One of our coolest and most useful features is our cost estimator.
"We use data from actual tradespeople that use our service, so it's accurate and up to date."
The ebb and flow of supply and demand gives the company a good handle on the industry, he said.
"We are seeing at the end of last year, and I think it's changing to be honest, that in the Auckland market it was harder to find tradespeople.
"That's why our service works, because rather than individual people picking up the phone and calling around a whole lot of very busy tradespeople that may not be interested, we do the work.
"We send out a bunch of leads to tradespeople and the interest rate ones that have availability at the time, they are the ones that show interest in the job and say, hey, I would like to come around, and the homeowners choose.
"If the labour market is a bit tighter we have to send out more of those leads before we get enough response.
"Because of the number of jobs posted, it would be an unmanageable amount of emails to send out to everyone so what we do is we send them out to those that we think would be best suited to the job first. Then if there is not enough interest we keep sending.
"Last year in the Auckland market we had to send out a lot more leads to get the same sort of response.
"It is quite a good indicator of how strained the markets are, but this year it has so far eased up a bit so we don't send out as many."
There was no real competition in New Zealand. Yellow Pages was "just a directory" and Trade Me Services reviews potentially lacked integrity.
"There is nothing stopping anyone doing a very positive review on someone. Mum can come along and review her son's business."
Straitlaced mums may well baulk at using a professional service with the irreverent name BuildersCrack.
Mr Wyn-Harris is not worried.
It's a name that's quite memorable and slightly cheeky.
"It is something we talked about when we first came up with it - if it was the right brand - but I think it is because it is memorable.
"That's the thing about a brand, it has to be memorable and you can turn it into whatever your service does.
"We do appreciate that some people have problems with it and won't use us, but on the whole our system works really well and we give people great experiences," he said.
