Low Energy Extension - Coldharbour2017 - ongoing

This project is for a low energy extension to a listed building in the village of Uffculme. Dating back to 1720, the house is full of historic character, and has seen at least three earlier extensions since it's creation. Each extension has made use of the prevailing construction technology of the era: 1720 - Cob, 1800's - Solid stone, 1980's concrete block, 1990's insulated concrete block. With this extension we're adding another chapter in the history of this dwelling, using insulated timber framing as the construction system this time.

Working with listed buildings can be particularly challenging. Yet this extension has been designed subserviant to the existing building and to have a light touch in it's physical connection.

The new extension has a pitched roof of traditional slates. Reflecting the modernity of the design, vertical untreated timber cladding is used for the external walls. The timber boarding contrasts with the existing dwelling to show the different ages of construction in a sympathetic way, and reflects the green ethos of this construction, creating a visually attractive building for the local area.

This project has been designed along the following key principles:

  • Achieve u-values of 0.15W/m2K through the roof and walls using high levels of natural wood fibre insulation. Total wall thickness of 450mm.

  • Achieve very good airtightness levels through good detailing and careful sealing of corners, service penetrations and openings.

  • Use materials of low embodied energy.

  • Locally sourced natural materials wherever possible.

  • Use healthy materials (Internal finishes with low or zero VOC’s).

  • Minimise water use (through low flush toilets and low water use taps and shower)

  • Minimise construction waste.

  • Use energy-saving light fittings.

  • Utilise a mixed mode ventilation strategy.

    • Summer time ventilation. Encourage natural ventilation via the high-level skylights, which have been designed with the living room windows to encourage the venturi effect of stack ventilation.

    • Winter time ventilation. Making use of a MVHR unit to control the ventilation, whilst retaining as much of the internal heat as possible via a heat exchanger.

This project is now on site and under construction. Please check our facebook and twitter feeds for updates on this project over the coming months.