Integral Features Claim

Its Friday I have a stinking cold so please forgive the dumb question, but when making an integral features CA claim for a commercial property, on the sale you presumably have to add the costs back again to the comp, just as you would for the sale proceeds of any other asset?

Trying to phrase and email to a client about why its not a great plan given he was BR in year of purchase and is most likely to be HR on the sale.

Ie Features worth (say) £10,000

Claim AIA £10,000 (current tax relief £2,000)

On sale balancing charge £10,000 (future tax charge £4,000, potentially £5,000 if things go well)

Feel free to insult and laugh at the sick person if I got this hopelessly wrong as I have rather muddled thinking today.