Low Energy House » Eco-Home

The Stewart Milne Sigma Home is an experimental housing project at the BRE in Watford. It comprises two dwellings which are among the country’s first Level 5 homes under the Code for Sustainable Homes

Eco-Home Timber Frame Solutions

Stewart Milne Timber Systems is one of the UK’s leading providers of timber frame solutions. The company designs, manufactures and erects a range of quality timber frame products for the UK construction industry. All timber and timber products are from managed sustainable sources.

Proposed Mass Production of Eco-Homes

Presented as two semi-detached homes one is finished and furnished as three but potentially a four bedroom four storey townhouse. The other has been left unfinished in order to highlight the technology and the flexibility to create alternative layouts.

The eco-home is envisaged as a future semi or terraced property forming semi-continuous urban frontages. Several different variants can be produced with different layouts, elevations and finishes. The demonstration house is finished externally in a combination of high performance insulated acrylic render system and timber cladding.

Eco-Home Design Concept

The Sigma Home is an update of the traditional 3 storey townhouse. Arranged over four levels to minimise the building footprint and to maximise affordability , the split level house adopts a semi open plan form suited to today's informal lifestyles. Daylight is plentiful and the circulation core feature adds views and communication between spaces. Key to its design is the ability to separate the ground floor from its upper floors to create a self-contained apartment or a home office (thus reducing carbon emissions associated with traveling to and from work).

Eco-Home - Solar Chimney

On the roof of each eco-home is a solar chimney positioned above the staircase. The roof is orientated south at 36 degrees from the horizontal to allow maximum solar gain for the solar collectors positioned on it. The north facing window allows daylight into the stair and ventilation of hot air out in the summer. Passive air ventilation stack draws warm air up the stair well in the summer and out through the vents in the roof. In the winter automatic vents close to keep warm air trapped in the eco-home.

Eco-Home Insulation

The eco-home is designed to take advantage of solar heat gain. The high levels of insulation provided in the wall, floor and roof elements are coupled with high performance timber windows and airtight construction to ensure excellent thermal performance from the external envelope.

Eco-Home and Carbon Neutral Design

The eco-home is designed to be carbon neutral in terms of space heating , hot water , lighting and ventilation fans. High performance insulation and triple glazed windows make it a highly efficient design. The home also includes other carbon reducing measures such as low energy appliances, high efficiency condensing gas boiler, a home office and cycle storage.

Eco-Home - Passive Ventilation

A solar stack and ‘whole house’ mechanical ventilation and heat recovery system controls temperature in a passive system. The stack sits centrally above the stairwell and sucks in warm air as it rises, in a similar way to that of a chimney. A heat sensor opens and closes a vent at the top of the stack to control the optimum temperature in the eco-home.

Eco-Home and Renewable Energy

The Sigma Home utilises renewable energy by providing hot water from solar thermal roof panels as well as electricity from photovoltaic roof panels and wind turbines.

Eco-Home Low Water Usage

All showers, taps and the washing machine have low water consumption. An integrated grey water recycling system reclaims the water from the showers and washbasins for flushing wc’s. Water butts are provided to collect rainwater from the roof for watering the garden. It is anticipated that water usage will be kept below 80 litres per person per day.

The Sigma Home project has applied several leading-edge offsite building technologies. The smarter building process enabled the construction of two semi-detached four storey structures in 8 weeks from commencement to completion, compared to the traditional timescale of 24 weeks