Large detached house, West London

Major refurbishment and addition of basement, large detached house, West London.

Large detached house, West London

Overview:

Brief and Targets: Planning Targets of EcoHomes Very Good, 40% minimum for each of 3 Categories: Energy, Water, Materials.
Sustainability Initiatives: Fabric u-values designed substantially beyond building regulations. New double glazed windows well sealed in to walls to minimise drafts and enhance comfort. Hi-efficiency gas fired condensing boilers. MVHR and airtightness strategy. Responsible sourcing approach to materials.
Results:

Energy-critical data:

Floor area: 1400m2
Mass: The site is an existing 5-storey family house. It is proposed to remodel the property using the current shell as well as building a new two-storey basement under the existing footprint and garden to accommodate swimming pool, spa, steam room, gym facilities, theatre and staff quarters.
Structure: Existing masonry and brick envelope substantially retained with internal timber floors, walls and roof replaced with reinforced insulated concrete slab floors, new brick and thermalite block cavity walls full filled with tight fitting insulation and steel frame and timbered insulated new roof. FSC and PEFC responsible sourcing of timber.

Main materials:

Walls: U-value=0.22 External existing brick walls to be thermally upgraded internally with insulation and plasterboard.
Roof: U-value=0.15 Main Pitched Roof Insulated at joists
Floors: U-value=0.10 Reinforced concrete insulated floor slabs.
Windows: Timber or Aluminium faced low-e Double Glazed frames; 1.6 u-value for whole frame: Certificated.
Doors: Insulated timber frame doors: 1.6 u-value
Air-permeability: Conservative Design Air permeability rate – 9 m 3 /hm – opted for as high volume building with considerable scope for air leakage.
Psi-values: Generally N/A in this complex refurbishment but Enhanced Accredited Construction Details used with separate lintels for internal and external leaf.
Insulation: Applied above slab in basement and internally throughout.
Heating: (SAP2005) 95% Hi-efficiency gas condensing boilers for space heating generally via low pressure underfloor system and some radiators.
Controls: Time and temperature zone controls
Hot water: Single unit 700 litre Ormandy indirect HW cylinder
Ventilation: MEV system for upper floors and MVHR for below ground floors.
Cooling: Cooled area approx: 798m2. Energy label class A EER 3.4 SEER 4.25 Controls: On/off
Renewables: None
Low E lighting: 75% LED lighting internally and low energy lighting with dawn and dusk sensors externally

Points of Interest:

"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

30% of the water consumed in the home is flushed down the toilet. You can reduce the amount of water used in each flush by fitting special 'lo-flow' devices, or by contacting your water company for a free 'hippo' or 'hog'. These displacement devices are very simple to install or remove, and save 3 litres per flush.

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