Kym
Any money that you do not spend from your DLA or PIP becomes savings/capital at the end of the payment period, this is normally four weeks for these benefits.
Neither DLA nor PIP are affected by your savings, do you receive any Income Related Benefits such as ESA(IR), Income Support or Universal Credit. these have a savings rule.
Asset and savings rule There are no automatic disregards for savings associated with disability aids, you can request a disregard for certain essemtial building work such as house repairs or having a wet room instaed but these do not normally extend to aids.
Gordon