Ten years ago we added a 6 x 5m kitchen extension to our five bed non-listed period house in rural Wiltshire. It was a double height, vaulted ceiling extension with lots of floor to ceiling glazing. We had builders get to shell stage/first fix then we finished much of the interior ourselves.
Our architect reckoned we could do the shell for £20k!!! It came in at £40k which was still very cheap and by doing loads ourselves we saved ££££ 😉
We fitted a solid timber kitchen that came primed ready to paint (from an independent business we'd used before). This was far cheaper than using the usual suspects and looked very high end when complete. Because DH knew people in the bathroom industry, we got good quality sanitary ware etc for excellent prices too.
The whole renovation (rewire, new oil fired heating system, extension, two shower rooms, one bathroom, new engineered wood flooring in the reception rooms and limestone in the kitchen and utility, replastered and decorated throughout plus garden landscaping) cost £135k....
But like I said, that was doing lots ourselves.
Our current (detached, period) house in a fairly expensive part of rural Wales is considerably smaller and over the past four years we've spent £100k on - borehole, rewire, new oil boiler/heating, two wood burning stoves, knocking through/steels etc, reconfigured layout up and downstairs, kitchen from HMKOC, one bathroom and a cloakroom, utility, some garden landscaping, new slate roof on existing extension. Anything that can be DIYed we have!
We're not finished yet and plan to build a two storey extension (living room and bedroom) and a garden room, plus do more to the land. We've a smallish budget for this, but again will DIY and are in no mad rush (have to fit it in around the day job, lol!) as it's just us two these days. We've already stockpiled many of the materials needed, thankfully!
If we were paying trades, god knows what we'd have spent 😎