Set on a hill amidst four acres of land, the new build property complements the landscape and looks stunningly classical, thanks to the design from the leading traditional architect, Robert Adam, Director at ADAM Architecture. Simultaneously, the building boasts high energy efficiency and a breathing fabric, which ensures the health of the structure and those who occupy it.
Alexander House was constructed using NBT’s ThermoPlan Plus system. This system delivers a building with very high levels of comfort, which requires very low energy use. It does this through thermal coherence, air tightness, fabric moisture control and summertime overheating mitigation. The NBT Thermoplan fired clay blocks use a true thin bed mortar, just 1mm thick, with interlocking dry vertical joints to form the masonry wall. The simplicity of the construction process enables ThermoPlan block walls to be typically constructed three to four times faster than conventional blockwork structures, with no limitation on the height that can be built in a day and no drying out shrinkage.
In the second stage of NBT ThermoPlan Plus system construction, the ThermoPlan blocks are then overclad with a continuous layer of NBT’s Diffutherm woodfibre insulation, which delivers an external shell with minimal thermal bridging (typically, a y-value of 0.02W/m2K). This is then finished externally with NBT’s natural lime render.
A simple and robust construction method, the ThermoPlan Plus system offers Alexander House numerous benefits. The honeycomb cross-section structure of the ThermoPlan blocks and the woodfibre composition of the Diffutherm insulation deliver excellent levels of thermal coherence as well as high thermal and acoustic insulation values. Indeed, the use of NBT’s system resulted in an external wall U-value of 0.15W/m2K.
In common with all NBT solutions, the NBT ThermoplanPlus system delivers highly effective breathability, which safeguards the integrity of the structure and helps to deliver a healthy internal environment. It also provides crucial thermal mass, which helps to prevent overheating during the hotter summer months.
Both the ThermoPlan blocks and the Diffutherm woodfibre insulation add to the home’s sustainability credentials through their use of natural materials, recyclability, low toxicity and embodied carbon. The Diffutherm insulation locks up 1.2 tonnes of CO2 for every tonne produced, and the ThermoPlan blocks have 30% less embodied CO2 than a comparable cavity wall.
Other sustainability measures undertaken at Alexander House include the use of locally sourced, reclaimed Scottish Ballachulish slates and gravel, and a ground source heat pump to supply the under floor heating, swimming pool and hot water.