Work on fixed water and heating installations needs an autoriseret VVS-installatør (authorised plumbing contractor), or a firm that brings one. Ask which it is, and ask for that on the invoice (faktura). Authorisations are looked up at Sikkerhedsstyrelsen, sik.dk.
Køge is the hub along Køge Bugt, with jobs in town and nearby places such as Karise. Many houses are detached. A drive along the coast is common. The same 4 businesses as the Danish page: Finmann VVS/Entreprise ApS, KILDEGAARD VVS & GASTEKNIK A/S, STENKILDE VVS & GASTEKNIK A/S, Viteq VVS ApS.