Providing bonding etc is up to speck, could you offer just putting in a 2-way CU next to the existing?
I've told her I won't install the circuit without the board change
usually, if there are 2 or more circuits to be worked on that need an RCD, I'll try to get the customer to agree to a new consumer unit. Otherwise as Kingeri said upgrade just what is needed and be specific.
That's not how I read what he wrote. I take it he meant if there were 2 or more new circuits needing RCD protection then he would tell the customer they need a board change 1 circuit he would fit a small separate RCD boardSo are you suggesting you will install without RCD protection even if the regs call for them?
with a bit of careful planning
..... There's little or no planning or forethought involved, just the OSG and RCD mantra quoted as if it's the only option.
That's not how I read what he wrote. I take it he meant if there were 2 or more new circuits needing RCD protection then he would tell the customer they need a board change 1 circuit he would fit a small separate RCD board