It may be due to build-up in the pipes reducing the flow. However, based on current guidelines I've read, you should have at least 3/4" pipe if you have more than one fixture on the pipe. If you have the kitchen and the washer sharing a 1/2" pipe, I think its significantly undersized (both require quite a bit of water).

Bruce

Thanks Bruce.
Would the white vinegar recirculated though the pipes with build-up reduce the build-up and improve the flow without doing damage to the pipes? We have to avoid using the sink faucet, dishwasher or laundry at the same time. Only one at a time will work satisfactorily and the flow is still slow.

I used to live in Texas and deal with hard water. Vinegar usually helps with getting scale off fixtures or something where you can keep the vinegar in contact long enough to let it do some work. However, I don't know if it will work very well trying to clean out a pipe.

I would also take a careful look at any shutoff valves or other junctions that may be causing a restriction. New installations use ball valves for main shut-offs and quarter turn valves for sink line shutoffs. It might be worthwhile to have newer valves installed, since the valve may be a significant part of the restriction.

Bruce

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Thanks again! All the plumbing is new from the slab up on all but the kitchen. It was renovated in 1987 and will get new fixtures and plumbing within the next year. Some of the renovations in our neighborhood have used pex plumbing with apparent success. That may be in our future if we cannot get the flow problem solved otherwise. I think I will try the recirculation for several hours just to see if there might be any benefit. I can time the filling of a gallon bottle before and after to gauge the possible effect. I really appreciate your help.
Lee

Also consider the installation of a permanent recirq. system for the distant fixtures. during your renovation.