We live in a 1960s home. When someone is in the shower, and another person is shaving in the same bathroom (periodically turning on warm water), the warm water to the shower gets cool. This is more noticeable now that the weather is cooler, or it could be that our habits have changed a little and we are more frequently in bathroom together, not sure. We are planning on renovating this bathroom, but would be more inclined to pursue incremental solutions than a hugely expensive solution (we are not going to put in bigger pipes). We have a new gas water heater of an appropriate size, shower is not excessive in length, and there is no other hot water being used at the time. Some hot water pipes go through uninsulated crawl space which we should insulate. Will insulating the pipes help solve this problem? Awhile back I'd been looking at this forum while planning the bathroom reno, and I read about some device that prevents the water temp from increasing or decreasing more than x number of degrees. Does anyone know what this is called? Thanks.