I’m not in the habit of giving advice (well at least not until recently), but the one regret that I have (well in addition to forgetting to put solar panels on the original plans) was that we didn’t go ahead and install rainwater harvesting.
I had a quote for a large tank and a variety of pumps, pipes and valves that came out at around £2000 including VAT. This was way back when we were drawing up plans and rainwater harvesting got lost amongst them and never became a firm inclusion. It was a £2000 that was easier not to spend at the time. Now, that two thousand will soon flow away through the water meter when greener more sustainable ‘free’ water could have been used instead. Additionally, the barn would have had a rainwater infrastructure that would have lasted for a lot longer.
There is a lesson here – I didn’t ensure that my original design and budgets allowed for all the technologically and economically sound options that I should have. I was blinkered by the basic needs of walls, floors, roof, windows and doors and therefore my initial plan lacked in detail … this lack of detail has a financial impact, both short-term (I had to apply for planning permission for my solar panels) and medium to long term (we will need to pay for water we wouldn’t have had to and any attempt to retro-fit rainwater harvesting will be messy and costly).
As always, the devil is in the detail.