If it's a new build SPD's should be fitted as standard nowadays along with RCBO boards. As stated before, if it is an existing property and they already have smokes installed, like for like doesn't require an EIC therefore negating an SPD. If you are installing a new circuit/ alteration you will as it's supplying a safety device/s. This is the problem with our industry, regs are open to interpretation too often because of their wording of the regs.