This high spec property had to meet requirements in line with level four of Code for Sustainable Homes.

The clients choose to contract one of Germany’s leading house builders, WeberHaus, for the project.Their off-site manufactured houses are of exceptional quality, with excellent thermal efficiency & air-tightness along with triple-glazed windows, resulting in a reduced carbon footprint and lower running costs.

Better Planet was instructed by WeberHaus to design, supply and install the renewables including biomass, solar thermal, solar PV and underfloor heating. We were also instructed to install a sophisticated Energy Monitoring System which was a requirement under the Code for Sustainable Homes.


Services provided by Better Planet

  • A room by room heat loss calculation required to determine the size of the biomass boiler and for the underfloor heating design
  • Shading analysis and wind load calculations for the solar installations
  • Predictions of running costs as well as FIT and RHI payments
  • Design for all technologies including mechanical schematics, wiring diagrams and location of main components
  • Supply, installation and commissioning of the systems
  • MCS certificates for Biomass, Solar PV and Solar Thermal


Project Summary


  • A heat loss of 8.5 kW at a design outdoor temperature of -2.4°C.
  • Biomass boiler: HERZ Pellestar T-Control 205, 3 – 20 kW
  • Automatic Combustion Cleaning
  • Automatic Heat Exchanger Cleaning
  • A 1000 litre mild steel buffer tank
  • Yearly RHI payments (paid over 7 years): £1,947

Solar PV

  • Total output: 4 kWp
  • Panels: 16 Amerisolar polycrystalline 250 Wp
  • Inverter: Growatt
  • Estimated yearly FIT payments: £1,299 (paid over 20 years)
  • Panel warranty:Mounting system: HILTI low profile non penetrating system
    • Free from defects: 12 years
    • Power output 12 years: 91.2%
    • Power output 30 years 80.6%

Solar Thermal

  • Solar collectors: 30 evacuated tubes SunRain TZ58/1800 – 30R1 Series
  • Aperture area: 2.78 m2
  • Collector efficiency: 73%
  • Hot water cylinder covered with a 25 year warranty
  • Pump station: Barilla Dual Line
  • Mounting system: Non penetrating, 45 degree tilt, total ballast 320 kg
  • Yearly RHI payments (paid over 7 years): £309
  • Cylinder: Twin coil 250 litres manufactured by Advanced AppliancesSolar controller: Resol Deltasol C
    • Solar Dedicated Volume : 80 litres
    • Surface area of solar heat exchange coil: 1.10 m2
    • Surface area of auxiliary heat exchange coil: 0.75 m2

Under Floor Heating

  • System designed to operate with 40 degrees flow temperature at design outdoor temperature
  • Underfloor pipe: 1,479 meters of 16 x 2mm PEX AL PEX pipe
  • Manifolds:  Emetti
  • Room thermostats: Heatmiser network, controllable via internet

Energy Monitoring System

  • Monitoring System from Ewgeco
    • Immediate reat time data
    • Detailed graphical analysis