Extension 'innovation'

[Mancala57]

We are about to commence a simple single story side reveal extension. Was going to have a pitched roof with 3 or 4 aluminium type velux roof windows and some quirky radiators unless can extend to underflooor heating.

Friend has just extended and had charred thermocladding to aid heat retention. It has occured to me that I am doing nothing to possibly look at innovative heating/reduced long term bills or energy usage.

Just wondered if anyone had any tips for building design items to consider factoring in which might ensure a sung and low energy use extension (it won't get the sun in the mornings, more like late afternoon onwards).

*snug not sung

Plenty of new sustainable insulation materials and techniques to pick from. My walls are filled with some sort of eco wool but modern build requirements are such that the new bit at least will be very well insulated and snug! You can add additional heat retaining cladding but at a cost which is where most people start to shy away from the aspiration. You could consider thin joint block construction (fewer and thinner joints meaning less heat loss) which would help. material cost is higher but install time and therefore labour is less so kind of balances out. My builder shied away from it though as he didn't use it before.
LED lighting everywhere obviously. We have underfloor heating and it's bloody fantastic. If you wanted to be very controlling for heat / costs then consider multi zone heating controls and thermostats.
As with everything, anyone wanting the eco friendly and 'sustainable' solutions always pay more for the pleasure so budget decides most things.