Case Study – Larch House

Larch House

Passivhaus Newbuild

A Passivhaus certified 3-bedroom single storey home been designed by Mark Siddall from LEAP Architecture and constructed by Mac Eye Projects.  The Cotswolds-based project has made great efforts to minimise carbon emissions on the project both by building the project to the Passivhaus standard but also through its use of sustainably sourced timber throughout. It is also currently the UK’s most airtight home.

Larch House, Warwickshire

Mick Woolley

Name: Larch house
Location: Warwickshire
Construction type: Timber Frame
Completed in: June 2019

Larch House Team

Client: Mick Woolley
Architect & Passivhaus Designer: LEAP
ContractorMac Eye Projects
Certifier: Mead: Energy & Architectural Design Ltd
Airtightness: Aldas
Other Consultants: Alan Clarke

View the Image Gallery to see before and after pictures of the project. These have been collated by Aldas

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Passivhaus Awards

UK Passivhaus Awards 2021 Small Projects winner. View the project details from the Passivhaus Trust website

Airtightness Report

Download the Airtightness reports by Aldas

Larch house

Passivhaus Awards 2021

Small Projects Winner in the 2021 UK Passivhaus Awards, Larch Corner is a timber triumph. Matching Passivhaus levels of efficiency with low carbon materials, together with an Air Source Heat Pump & PV array, this rural detached home truly strives for net-zero aspirations. 

Larch House


12 x more airtight than required by Passivhaus and 244 x more airtight than Building Regulations, Larch Corner is one of the UK’s most airtight dwelling, with the equivalent leakage area fitting on a 1-penny coin.

Larch Corner is believed to be the most airtight house in the UK and the third most airtight house in the world. The record-breaking airtightness result of 0.047ach@50pa is a testament to the commitment of the team and their attention to detail. To accurately measure such a low-level air leakage, airtightness expert Paul Jennings of Aldas was compelled to recalibrate his fan, and ATTMA attended the test as an independent witness. 

I love Larch Corner. It gives me a wonderfully quiet, calm and comfortable home that is extremely economical to run, and I really appreciate the superb daylight.
Mick Woolley – Client

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