New boiler - Day 1

After thinking about for long enough I finally decided to replace the central heating system with a modern one, in the hope of reducing my greenhouse emissions (or at least my monthly spend on gas). After doing the  quotes and all through  the summer today was the agreed installation day. The parts were due this morning with 2 teams arriving this afternoon. The work would be done by Wednesday evening.
As expected the new boiler and various parts arrived this morning. and shortly after lunch a single Scottish Gas installer arrived and apologised for being so late. It seems the job was due to start at 8 this morning with only the single guy. Bad start but hopefully not an omen...
The guy started examining the paperwork and scratching his head. It seems the job was oversimplified on the job sheet and it looks like its going to be a bit tougher then expected.
The problem is the gas supply has to be 3/4" but the old boiler only needed 1/2" so the 3/4" pipe is reduced somewhere between the meter at the front door and the oven at the back of the house. We are presuming that the pipe is running underground beneath the house, so there is no way to find the current reduction point and replace it as it could be anywhere between the two. A quick check next door shows their gas pipe runs outside along the base of the pebble dash, apparently confirming the idea that the pipe is not available for connecting to.
Sadly, running the pipe outside from my meter to the back to the kitchen means it crosses the front door and that doesn't look (or seem) right.
My installer gives up and refers it back up his management chain, telling me that someone will be in touch.
Later on I speak to next door. Their gas supply actually comes out of the bottom of the meter under and into the house and then up to the first floor, across the house and down into the boiler, and then down to the cooker. They didn't want to the effort of finding were the pipe reduced indoors and just by passed the entire search. It would be odd if mine was any different...