Greenenergy

Zero-carbon Homes

Zero-carbon Homes

The efficiency of your home is determined primarily by the construction fabric of the external ‘envelope.’ Our eco-friendly kit houses provide high insulation and glazing levels to reduce the heating load on the dwelling, working towards the government target of providing zero-carbon homes. The main design principles we follow for the fabric are:

  • Maximizing air-tightness
  • Using high performance insulation materials
  • Reducing thermal bridges
  • Using the thermal mass of the building fabric

We work closely with a services engineer and renewables partner, Lo3 Energy, which can advise on, design, supply and maintain a wide range of technologies including:

  • Air source heat pumps
  • Ground source heat pumps
  • Wood stoves, back boilers and thermal stores
  • Biomass boilers
  • Biomass combined heat and power (CHP)
  • Solar thermal
  • Underfloor heating
  • District heating

We recommend you choose an energy efficient system as conventional alternatives will mean you have to spend more money elsewhere in the building to compensate for the higher emissions.  An options appraisal, which looks at both capital and running costs, as well as comparative efficiency, will help you make an informed decision on which system is best to invest in.

The most common technology for a renewable system at the moment is the air source heat pump (ASHP) which is very competitively priced and also has government financial support through the renewable heat incentive (RHI). The Energy Saving Trust will have the latest information on financial support available.

To get a building warrant in Scotland we must provide a ‘SAP calculation’ which estimates the carbon emissions related to the building in question. This is a standard document which encompasses the fabric performance, and the heating, ventilation, cooking and lighting energy use of your home. When we have prepared a detailed design and a SAP calculation, our services engineer consultant will liaise with you to discuss the options available in passing the carbon targets.

These options, in brief, are as follows:

Option 1: Pass the Building Regulations
We will provide a standard structurally-insulated panel (SIP) or timber frame house kit in line with building regulations. This is already energy efficient and will typically attain an energy performance certificate (EPC) rating of C. We would recommend this approach for those with constrained budgets.

Option 2: Exceed the Building Regulations
We can provide a high performance kit with better U-values and systems for a low energy home. By upgrading the windows to triple-glazing and add renewables systems, the house could achieve an EPC rating of B or above.

Option 3: Build a Net Zero Home
A ‘net zero home’ costs nothing to run as you generate your own electricity and have super-efficient heating and ventilation systems. Such a house would achieve an EPC rating of A.

Option 4: Build a Passive House
A Passive House is the highest performing specification, allowing heating systems to be removed completely. This certification was developed in Germany and we have accredited suppliers and consultants that can deliver this gold standard of energy efficiency. Find out more.

Once complete, the house will be given a SAP rating from zero to 100, with 100 being the most efficient, based on the energy-related running costs of the dwelling. This demonstrates compliance with building regulations (Part L in England and section 6, energy, in Scotland).

Early discussions with our team will allow us to design to the standard that best suits your budget and your aspirations.