A template for homes of the future : Moonstone - a case study

From its first inception, developer John Croft had a dream to build his own home in the idyllic setting of the Cotswolds. It took a few years, a lot of patience, research and work to make this home the best it could be.

Built on the site of old industrial buildings, the first challenge was to design something that would cope with a valley sloping steeply to a stream at the bottom. Whilst the isolation of natural waters seeping from the rocky slopes was a massive technical hurdle, the location allowed John the opportunity to create a multilevel (seven in all) 16,000 sq foot/1,500 sq m home, with a third of the structure underground, filled with natural light and unspoilt views of the wonderful countryside just outside Cheltenham.

ArchiCAD BIM, EcoDesigner and Virtual Building Explorer

Having been recommended ArchiCAD by a colleague from the University of the West of England, and armed with the initial 2D sketch design and xyz site survey data, John visited the Homebuilding and Renovation Show which is where he first received a full demonstration of ArchiCAD Building Information Modelling software. John states: “ArchiCAD, is an architectural design software with refined 3D modelling, 2D documentation and excellent presentation tools.”

ArchiCAD's Virtual Building model concept creates a digital model of a design, storing all related information in one single project file. From this integrated model database you can quickly and efficiently produce plans, sections, elevations, construction details, schedules and building management information.

After just two day’s hands-on tuition John was able to model the whole project from the base 2D drawings, highlight inconsistencies and potential design faults as well as incorporating the 3D landscape terrain of the site, placing the house in context.

John adds: "ArchiCAD BIM is a tool we definitely could not have lived without. It certainly saved us tens of thousands of pounds in cost savings on the project as we were able to analyse any design mistakes, clashes of materials, know where the MEP runs were going to go as well as evaluate building performance. VBE really is quite bizarre - playing around your house in a real time model is very, very impressive."

Fully integrated into the ArchiCAD BIM workflow EcoDesigner performs dynamic building energy evaluation including annual consumption, carbon footprint and monthly energy balance. Virtual Building Explorer (VBE) sets new standards in design presentation as, uniquely, its navigation and display includes the building information model instead of just a presentation model (www.applecoredesigns.co.uk.)

The house is not even connected to a mains water supply

The house literally needs no energy as it is designed to meet, or exceed, the very highest environmental standards, whilst providing a beautiful and practical family home. With fastidious attention to detail, John has created an ultra-modern space filled with the best in environmental, security and entertainment technology, without sacrificing any of the interior design needed to create a comfortable home.

The house is not even connected to a mains water supply - rain water from the immense curved roof area and driveway is harvested and stored underground in giant tanks. A two tier vertical reed bed natural filtration system converts black and grey water into a fresh supply for drinking, washing and flushing.

All windows are triple glazed with U values down to 0.7K, and the exterior wall has a full 1/2m of solid stone and a further ½ m of solid state of the art extruded waterproof insulation as a thermal skin, giving insulation values 65% better than the very best Passivhaus standard (U=0.06W/m2K). The inner wall is deliberately constructed from dense concrete block which acts as a heat sink in summer and a heat source in winter. This means that, in theory, the house is so well insulated that the heat given off by the individuals inside would be enough to heat it. The house has, on average, around 0.5 metres of insulation incorporated within its walls, floors and roof. 80% of the house’s energy is generated from PV cell arrays on an outbuilding wallside which supply more electricity than the house uses, the surplus being fed back into the grid, generating an estimated income of £3,500 per year.

As a testament to the energy efficiency of this home, John’s under-floor heating, powered from a 44 square array of Solar thermal panels with a ground source heat recovery system backup, was used for a total of only six days during the bitterly cold winter of 2009/10, when the outside temperature plummeted down to - 13 degrees celsius for a three week period. In fact John’s house derived 92% of all its hot water and heating demands entirely from its large solar thermal array, feeding two monster 1500 litre stratified solar thermal stores.

The house is lit entirely with energy efficient RGB based LED lamps. Creating white light from component Red Green and Blue LED’s actually uses less energy, capital cost is lower and the overall colour spectrum is much warmer than white LED based lamps.

Displaying a totally unique and contemporary design, which integrates the very best in, quite literally, unseen entertainment, security and environmental control together with a non-existent operating carbon footprint, this must be the template for homes of the future.