General Terms

  • Retrofit – Converting an existing building to be more energy efficient. For the definitive guide, we’ll hand you to the government approved retrofit quality assurance agency Trustmark to explain more… read more.
  • FSC stands for ‘Forest Stewardship Council’. FSC is an international non-profit organisation dedicated to promoting responsible forestry. FSC certifies forests all over the world to ensure they meet the highest environmental and social standards. Products made with wood and paper from FSC forests are marked with the ‘tick tree’ logo. When you see this logo, you can be confident that buying it won’t mean harming the world’s forests. You can find our timber purchasing policy here: Timber Purchasing Policy (
  • ESG Short for “environmental, social and governance,” ESG represents a more stakeholder-centric approach to doing business which looks at the relationship and impact an organisation has on each. Companies that adhere to ESG standards agree to conduct themselves ethically in those three areas, and can draw on a range of ESG strategies to do so. At Bradfords we are preparing our first ESG focussed report to be ready for September 2022. We’re already doing lots of great activities which support our ESG strategy, but our task now is to ensure that we have a robust framework to capture this and drive the right actions looking ahead.

Heat and ventilation Systems

  • Air Source Heat Pump – Often shortened to ASHP. In simple terms, an air source heat pump works like a reverse fridge, extracting warmth from the outside air before concentrating it and transferring it indoors to provide central heating and hot water. The pumps look like a standard air-conditioning unit and need to be situated outside the home. Set up in conjunction with the right system through a house, air source heat pumps represent the most efficient way of converting energy to heat, with the best getting between 3-4kWh of heat for every kWh of electricity used. The government target is to see 600,000 of these (or equivalent low carbon systems) per year installed into both new builds and existing homes by 2028.
  • Ground source heat pump – A ground-to-water heat pump transfers heat from the ground outside your home to heat your radiators or underfloor heating, and your hot water system. The principle is the same as for an air source heat pump, the difference simply being that the heat is extracted from the ground rather than the air. Ground source heat systems can be laid relatively shallow over larger areas, or very deep over a smaller area. There are benefits and compromises for both, so get in touch if you want to know more.
  • Heat Battery – Heat batteries are energy-saving thermal stores that efficiently store heat for hot water and space heating on demand. In simple terms they are a modern storage heater, but technological developments mean that they are super-efficient. For traditional homes not on the mains gas grid where fitting an air source system would be very disruptive, these offer a great alternative.
  • MVHR – Mechanical Ventilation with Heat Recovery (MVHR) is a continuous source of ventilation that extracts stale, moisture-laden air from a building and resupplies fresh, filtered air back in, resulting in a comfortable and condensation free environment all year round. At the same time they balance the temperature around a property recovering heat from air before it is extracted from the building.


The tech behind it all that helps us to explain and calculate what you need to do to achieve certain standards.

  • U-Value – U-values measure how effective a material is as an insulator. The lower the U-value is, the better the material is as a heat insulator. U-values are used to describe the thermal performance (heat loss) for individual elements of a building, or for parts of or the whole house. To achieve a specific U-value for your building, you need to figure what combination of materials you need. Doing this properly, you can make savings on both cost and amount of material you use without compromising on the U-value you achieve.
  • Thermal Bridging – The movement of heat across objects more conductive than objects around them. To maximise the effectiveness of insulation measures, you need to minimise thermal bridging. Check out this handy guide from Xtratherm: Thermal Bridging – Xtratherm.