Major refurbishment, Hampsted, London

Major refurbishment of existing substantial detached house. Grade II* listed building

Major refurbishment, Hampsted, London Major refurbishment, Hampsted, London


Brief and Targets: The Council’s Planning Consent contained a number of targets, including EcoHomes Very Good with 60% under the Energy, Water, Materials and Waste Categories. There was also a requirement for a 15% carbon reduction against Building Regulations, and for this size of property the Local Authority favoured CHP to supply the heating and hot water.
Sustainability Initiatives: Abba’s first task was to examine an existing energy strategy and by advising on better fabric U-Value standards the energy targets were met.
Results: EcoHomes Design Stage ‘Excellent’ Certificate and Planning Targets met. Site work not commenced yet.

Energy-critical data:

Floor area: 1,615 m²
Mass: Single detached dwelling, demolition of the existing garage block and erection of a new west side wing comprising basement, lower ground, ground and 1st floors including a garage LGF-level parking.

Main materials:

Walls: U=0.28, New brick cavity wall in the west side extension.
Roof: U=0.18, New terrace U=0.18, New lead roof to the extension house.
Floors: U=0.22, New Basement - Screeded concrete slab U=0.22, LGF -Screeded concrete slab. Upper Floors as existing.
Windows: U=1.60, Existing windows to be replaced with timber double glazed, 16mm gap, soft LowE argon filled, draught sealed windows U=1.60, New windows to be timber double glazed, 16mm gap, soft LowE argon filled, draught sealed windows U=1.60, Roof windows to be Aluminium double glazed, 16mm gap, soft LowE argon filled, draught sealed windows.
Doors: Timber doors
Air-permeability: Max 10 m3/m2@50Pa
Psi-values: Default y=0.15
Insulation: GWP<5 (various)
Heating: 3 no. of High efficient condensing boilers
Controls: Time and temperature zone control
Hot water: 2 no. of 1,919 litres HWC
Ventilation: Extract ventilation to kitchen, utility rooms and bathrooms. MVHR limited to the basement
Cooling: Area cooled=522.2 m², VRV system, Energy class A
Renewables: None
Low E lighting: Min 90% to be Low-E

Points of Interest:

Certified EcoHomes Excellent at Design Stage, prominent site in Planning terms, sensitive building in Conservation terms with guidance to retain as much of the existing fabric as possible, challenging building to balance the energy strategy with the retention of favoured features.
"This is our first experience of working with Abba – they have been professional, constructive and helpful and we would certainly look to use them again on our next project." - Gradeview Properties

Sensible Energy Saving Tip

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New Build or Domestic Refurbishment? Call Abba Energy on 020 8208 8333 for expert advice on Sustainable Housing Design and Construction.