Passivhaus Affiliate

Mayfield Passivhaus certified

Complete and occupied in September 2015, Mayfield Passivhaus has finally received the gift of Passivhaus certification for Christmas 2016. This is the first certified PassivHaus for the client, the architect and the contractor.  

The client is based in London and East Sussex, with the time spent in each location varying depending on their work commitments.  The original 1930s bungalow on the site had a very poor thermal performance and took a day or two to get to temperature on each visit. In researching ways of delivering a high performing house the architect, Hazle McCormack Young LLP, thought a highly efficient thermal envelope was an obvious response to this and put forward the option of aiming for Passivhaus.

Mayfield Passivhaus certifiedMayfield Passivhaus key team with certification plaque

Set within a historic Percy Crane landscape garden, the new Passivhaus dwelling provides 6 bedrooms over three storeys and responds to the layout of the historic garden setting, with footpaths and vistas becoming integral with the layout of the rooms and glazing.

 Mayfield Passivhaus Mayfield Passivhaus

The house is a three dimensional venn diagram, with two volumes overlapping in the area of the main entrance atrium and staircase, which fall on the principal axis of the site entrance route.  This mutual overlapping zone is expressed externally in a full glass roof over the entrance atrium, bringing light and winter warmth into the nucleus of the house.

Mayfield Passivhaus Mayfield Passivhaus

Internally, the layout reflects the order of priority of its users, with the kitchen and dining space taking the most prominent position off the south-facing terrace.

 

The budget was always a challenge for this project, with a finite amount available for the spend, but with growing aspirations for what the house needed to provide.  The procurement route was chosen to deliver best value for money and involved an open book negotiated contract with a not to be exceeded contract sum.

James Galpin, HMY Architects


Mayfield Passivhaus

The project has been shortlisted for the Sussex Heritage Trust Awards, and looks like a strong contender for the 2017 UK Passivhaus Awards.

 

Performance & Construction

The 569m² scheme (with a TFA of 449) utilises off-site prefabricated timber frame construction.

  • Wall: Factory-built timber frame with 18mm Siberian Grade A Larc7 hit and miss cladding externally on 50x50mm battens on Protect TF200 thermally reflective breather membrane on 9mm OSB boarding to 400mm I stud frame packed with Rockwool insulation and lined with 15mm OSB with Proclima air tightness membrane internally, with 50mm service cavity insulated with Rockwool insulation and 12.5mm British Gypsum boarding internally.

  • Roof: Marley Duo Modern interlocking fibre cement roof tiles on 38x25mm battens on 50x38mm counterbattens on TF200 thermally reflective breather membrane on 50mm rigid insulation on 300mm euro joist rafters with Proclima vapour control and air tightness membrane internally, lined with 50mm services cavity

  • Floor: 350mm insulated raft foundation by IsoQuick with 100mm boot upstand to insulated raft on 50mm sand blinding on 300mm compacted hard-core. Intermediate floors are eurojoists with engineered timber flooring over.

  • Windows: Norrsken Passiv Triple Glazed aluminium thermally broken windows U-Value 0.84W/m²K

Thermal Energy demand (≤15kWh/m2.yr)

15kWh/m²yr

Primary E demand (≤120kWh/m2.yr)

95kWh/m²yr

n50 ACH@50pascals (≤0.6ach@50pascals)

0.5ach

U-values

Wall - U-Value 0.087W/m²K

Roof - U-Value 0.082W/m²K

Floor - U-Value 0.105 W/m²K

 

Key Team

Architect: James Galpin, Hazle McCormack Young LLP

Client: Private 

Contractor: Richardson & Peat

Structural Engineer: Crouch Waterfall

Services & PHPP Consultant: Aaben Ltd

Certifier: WARM

PHT members, Hazle McCormack Young Architects, and the contractor are both working on several further PH projects. 

 

Further Information

Hazle McCormack Young LLP

A replacement dwelling on the site of a 1930s bungalow.  Set within a historic Percy Crane landscape garden, this new dwelling provides 6 bedrooms over three storeys and responds to the layout of the historic garden setting, with footpaths and vistas becoming integral with the layout of the rooms and glazing.

 

The house is a three dimensional venn diagram, with two volumes overlapping in the area of the main entrance atrium and staircase, which fall on the principal axis of the site entrance route.  This mutual overlapping zone is expressed externally in a full glass roof over the entrance atrium, bringing light and winter warmth into the nucleus of the house.

 

Internally, the layout reflects the order of priority of its users, with the kitchen and dining space taking the most prominent position off the south-facing terrace.

 

22nd December 2016


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