We have an old home and would like to keep with the period where possible. I have a marble vanity top with individual faucets for hot and cold rather than a single spigot for both. I can buy brand new replacement faucets that look exactly correct. Does anyone know if that is allowed by current plumbing code?
Plumbing code is generally unconcerned with the style of whatever fixture you choose to install, only that the fixture work properly and be installed properly.
Standard bathroom faucets come in versions that have the faucet handles on 4" centers, 8" centers, or separate pieces that can be placed at any distance apart.
I have never heard of a jurisdiction whose building codes require a specific distance for handle centers. But to be certain, check with the local plumber who will be installing the fixture.
Plumbing code allows this. Styles are not covered under building codes, generally safety and quality are what building codes are after.