Passivhaus Affiliate

Lichfield's historic St John's begins Passivhaus development

St John's Hospital was established in 1135 as a place of hospitality for pilgrims visiting the shrine of St Chad in Lichfield Cathedral.  The owners and clients seek to provide modern apartments designed for independent living for older people with neighbourly support and care.  18 new Passivhaus units started on site in July 2015 within the grounds of the grade 1 listed Hospital of St John Without the Barrs. The homes are to be built around a courtyard area and comprise two wings:

  • One wing to be certified as one block of 14 one bed apartments.
  • One wing to be certified as two thermally separate blocks each containing 2, two bed apartments.

 

Site Plan. Image credit: KKE Architects

Construction:

The apartments will blend into their surroundings with pitched roofs and brick walls; Constructed with a mineral wool filled cavity wall, and solid concrete floors with rigid insulation above.

 

Wing 1

Wall

 

  • 15mm Plaster
  • 100mm Hemelite  
  • 170mm Isover mineral wool  
  • 100mm Brick outer leaf

 

Roof

  • 65mm Cold roof Thin-R XT/PR
  • 150mm Isover Spacesaver Plus (timber fraction) 

Floor

 

  • 80mm Screed 
  • 30mm Thin R XT/UF 
  • 125mm Thin R XT/Hyfloor 

 

St John's Almshouses. Photo credit: KKE Architects

Predicted Performance:


Wing 1

Wing 2

 

Block 14 flats

East Block 2 flats

West Block 2 flats

Treated Floor Area (m2)

789

134

134

Thermal Energy demand (≤15kWh/m2.yr)

9

11

12

Thermal Energy load (≤10W/m2)

10

11

11

Primary: E demand (≤120kWh/m2.yr)

101

115

117

Form Factor (ext. area/TFA)

2.1

3.06

3.19

 

Both blocks have external walkways to access all apartments.  These timber and brick structures provide overhead shading in all orientations.

The building services design is particularly unique as this will be the first domestic Passivhaus to be built in the UK with a centralised MVHR and heating system. The heating and hot water for all 18 apartments are provided by two 30kW gas boilers with SAV flat station heat exchangers in each flat.  The larger wing has a centralized MVHR system servicing 14 apartments.

Left: MVHR diagram. Image credit - Green Building Store.

 

The ground breaking ceremony attendees included the Lord-Lieutenant’s Deputy, Mr Simon Clark and Mrs and Mrs Mack MacCormack (St John’s longest residing residents).  The welcome and introduction was led by the Chairman of Trustees Mrs Kathryn Duncan Brown. Photo credit: Sarah Price, Encraft.

 

Key Team

Client: The Trustees of St John’s Hospital, Lichfield

Client's Agent: Greenwoods

Architect: KKE Architects 

Passivhaus & M&E Consultants: Encraft Ltd 

Quantity Surveyors: Firmingers LLP

CDM Coordinator: Greenwoods

Contractor: Paragon Construction

Structural Engineer: Mark Brock Consulting Engineers

 

Further Information:

Encraft Ltd

KKE Architects

28th August 2015


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