For some, the choice of a passiv-standard house and a gas boiler for hot water and UFH provision would appear to be an odd one. Why not fit a ground or air-source heat pump (GSHP/ASHP)? Well, a number of reasons actually. GSHP aren’t cheap (could easily be £15k+ by the time it’s finished) and they require a fair bit of land into which the pipes are buried. Although our garden is a reasonable size, not all of it would be suitable for laying the pipework. ASHP aren’t particularly efficient and still quite expensive, although they are a chunk cheaper than GSHP. Gas on the other hand is pretty cheap to install and run – and we have a gas main running right across the front of the plot. On top of that our heating demand will be extremely low so paying out more than a couple of thousand for hot water just doesn’t stack up. Being efficient is far more important to us than fitting ‘stuff’.
I’d been warned many times that getting the utilities organised and connected was probably the hardest, or least most frustrating, part of the build. Not wanting to be caught out, I made initial contact with each supplier very early on in the process – I knew the gas connection wasn’t a priority but I still wanted to be on top of it all so I made the initial call to get it kicked off even before we’d broken ground.
That call amounted to Good News – the connection was relatively cheap (£400-ish); we had the option of digging the trench on our land for the pipe ourselves or letting them do it; and they only needed 4 weeks from start to finish. Easy! So I parked it.
Fast forward to the end of March and talk of needing to get the UFH up and running started. Obviously, we wanted to get it working in case there were issues that would need resolving but we also needed to get the floor fully dried and the system ‘run in’ before we laid the wood flooring and tiled the utility room floor. No problem, I’ll just get the connection sorted – it’ll be about 4 weeks.
One phone call later and 4 weeks became a stated 6-8 weeks! Major panic ensued, in me at least. I got the groundworks guys to dig the trench at the side of the house and National Grid came out to survey the site. All good except they weren’t happy with the duct I’d had installed in the wall of the plant room through which the gas pipe would route and instead they insisted that they drilled the hole themselves. Not in my house you’re not – you’ll use the duct! We had a discussion and everyone agreed that I was getting my way, which was nice 🙂
While the trench was open we had the BT duct, water pipe and a duct carrying the mains electric to the house laid at the appropriate spacing and depths. National Grid actually laid the gas pipe at the end of April – almost 4 weeks to the day after my initial order! Naturally I then proceeded to forget that I needed a gas meter. School boy error.
You’re generally given a few options by National Grid as to where the meter is to be located. I think these days they like to fit them in a cabinet set into the external wall. Now, not only do they look ugly but in a highly insulated and air-tight house they are a Very Bad Idea. Another option is to have one installed externally at about ground level. I don’t like these either but if that’s what we have to have then so be it. In fact we didn’t need either of those two options and were able to put it inside the plant room right by the boiler, exactly where I’d planned for it almost a year earlier!
Meter installed (despite a load of par-for-the-course whinging by the installer) and we were up and running. Boiler fired up, UFH running, no leaks. We were in business. Of course, we were now into June and the weather was warming up. Good insulation, an air-tight structure, large amounts of glazing, high external temperatures and a UFH system that was being slowly ramped up to maximum isn’t a good mix. It was HOT inside the house. Really hot. Too hot to work comfortably, that’s for sure. No surprise then that the electricians switched it off a couple of times! One saving grace is that we’ve built on top of a hill (the slab is 79.00m above sea level) and with the windows and doors open we get a lovely breeze through the house, which did help to cool things down somewhat. It was still warm though.
Anyway, it’s off now. The next job is to try and work out which pipe belongs to which room/loop so we can fit the thermostats. I ‘think’ I know which is which but I’m sure we’ll find out sooner or later.
Just one last job before I forget. The plant room was looking pretty untidy as I hadn’t bothered to connect the red MVHR ducts to the distribution boxes. I decided it was time to fix that. I’ve got a couple that I’d like to tidy a bit better, but it’s looking pretty neat now I think.