The House in Richmond was originally constructed of mass concrete walls, and had a cavity wall extension constructed to the rear of the dwelling. As with many houses, Internal insulation or drylining to any effective depth would reduce the internal floor area significantly. In addition to this, Mass concrete walls transmit heat well, and therefore the risk of interstitial condensation behind any drylining would be significant. In addition to this, as the house is semi-detached of modestly size, the external insulation grants (from the SERVE project) would cover a large percentage of the cost of the retro-fit. In additionthe external wall insulation the homeowner upgraded almost all other areas from an energy point of view: • Replacing an inefficient oil fired range with a high efficiency condensing oil boiler • Installation of a low loss cylinder and controls • Roof insulation • Space heating controls • Windows To get more information download the case study where the measures are detailed in terms of technologies, prices, energy saved and pay-back.