Insurance from exchange

[LividLaughLurve]

Our solicitor has sent a letter saying they need to see evidence of buildings insurance from the date of exchange.

Exchange date hasn’t been set yet.

Before I phone them up, anyone know how that works?

I presume they mean the mortgagors need evidence. It is advised to insure from exchange (when you are legally committed), not completion. Maybe it's a friendly reminder for some advance planning.
You can start investigating insurance (broker, comparison sites etc) now but not actually buy a policy until the exchange date is known. Have a look before you phone the solicitors because the website may throw up some questions that you need to throw back to them.

(I know it's for contents, not buildings, but the concept is the same)

It sounds like the solicitor is just making out aware of the need to insure the building immediately upon exchange - not everyone is aware that they need to insure from this point (rather than from the day they move in) and that the lender will require sight of buildings insurance in place before they’ll release funds ahead of completion: you just take out the insurance on the day you exchange and send the certificate to your solicitor.

If you don’t yet have an exchange date then just confirm to your solicitor you understand the requirement and that as soon as you have a date set you’ll take it out and provide the certificate.

Do you already have house insurance on your current property? Most insurers will cover your new house between exchange and completion as long as you tell them.