The new home is missing heating equipment as per specifications and has low water pressure

Ectophile

Cessello said:

Ectophile said:

There's a limit to how fast a combi boiler can heat water.  It has to heat the water in from cold to hot in the short time it takes for the water to flow through the heat exchanger.  With the ground outside getting colder, that makes the incoming mains water colder than it was in the summer.

There may be a valve you can adjust to choose between an inadequate flow of nice hot water, or a really good flow of vaguely warm water.

Now I doubt that the builder might do something like this to convince me that there is enough pressure. How do I findout this valve? 

Try looking for a valve on the cold water pipe going into the boiler.  It may be partially closed to restrict the flow.