Opportunities for maximising energy efficiency in different building types

Whether your organisation’s energy estate is large or small, there is one thing that is certain, the types of buildings you occupy will influence the way you should manage its energy.

A building’s performance

A building’s design and construction will affect its energy consumption performance. There are several varying characteristics to consider when looking at maximising the efficiency of energy use, these include:

  • Thermal mass of the building structure
  • Wall to window ratio
  • Air Conditioning
  • Levels of insulation
  • High ceilings
  • Solar heat gains
  • Ventilation

In this blog our Energy Consultant, Juan Garcia, focuses on four building types that are predominantly impacted by these characteristics, giving an overview of each, and offer a few opportunities for maximising their energy efficiency.

Listed or Period Buildings (pre-war)

Period building


If your business has listed or period buildings, they will usually have solid walls and a pitched roof. Typically, these types of buildings have a high thermal mass, low levels of insulation, single or double glazing, natural ventilation and high ceilings.

Opportunities for improvement

  • Review historical upgrades of the lighting and fabric, and find out how long ago were they last upgraded. Try to prioritise upgrading any of these elements that are older than 10–15 years. Replace all existing fluorescent lighting with LED units with built in occupancy sensors for an easy efficiency improvement.
  • If you do not already have them in place, weather compensation heating controls are an energy efficient way to support a building’s thermal mass and improve user comfort at a low cost.
  • Insulation can be added or topped up in lofts, around doors and improved with interior secondary glazing panels (as double glazing is not usually possible). Internal wall panels could be installed that will fortify the brick wall’s insulation, scale down the thermal mass and reduce heat loss through the fabric, lowering your energy costs.
  • Old properties rely on adequate ventilation to deal with moisture and damp penetration so when adding insulation or secondary glazing consider that extra mechanical or natural ventilation may be needed.
  • Where there are high ceilings, heat stratification can be reduced by using ceiling fans, this will minimise how much heat is used to keep the working space conditioned.

It is worth remembering if the building is listed, there will be restrictions on any alterations that affect the external appearance, internal fabric, character, or special interest of the building. Your local planning department or conservation officer will be able to advise you.

Post-war to 1980s Buildings

Post-war to 1980 building

Like period properties, most of these buildings are of brick construction, either cavity or solid wall. There is a lot of variation, but they tend to have low levels of wall and roof insulation.

Opportunities for improvement
Due to their solid design and construction, properties from this period tend to be more efficient so there are fewer opportunities to improve their efficiency. However, there are a few changes we recommend investigating:

  • Quick wins for these types of buildings include increasing the amount of roof insulation (there can only be a thin layer present in buildings of this type) and retrofit cavity wall insulation if not already done.
  • Ensure all windows and doors are double-glazed and draft free.
  • As with older buildings any added insulation will need to be balanced with suitable ventilation to avoid condensation or dampness.
  • If the heating system is more than 10-years old, it is worth considering replacing it to improve the efficiency of your heating. While the initial outlay of this is higher than some other measures, you will recoup the costs from the efficiency gains.
  • The options that deliver long-term payback include internal wall insulation and renewables such as PV or solar thermal heating.

Modern Offices from the 1990s until Present

Modern office building

Buildings constructed from the 1990s onwards benefited from the updated Building Regulations standards, meaning they were built with a certain level of insulation. Many will be cavity wall construction, or have curtain walling, and double glazing.

Depending on the layout or design, some properties will have an atrium where stratification of the heat may occur. Unless the property has been built or significantly refurbished in the last 5 years, the lighting will most likely be fluorescent.

Opportunities for improvement

  • Replace any fluorescent lighting with LED and add lighting controls such as occupancy sensors and light-level sensors near the windows.
  • The use of Natural and Night-time Ventilation can significantly improve comfort in buildings without air conditioning.
  • In buildings with air conditioning, consider upgrading to systems that use evaporative and free cooling which can reduce energy consumption.

High rise buildings with glazed walls or buildings with a high window to wall ratio.

High rise glazed building

High rise buildings usually have large areas of glazing. Whilst they look impressive from the outside, these buildings can perform quite poorly in energy efficiency terms. Glass has a much higher rate of heat loss than an insulated wall (up to 10 times higher).

Most buildings have a deep plan layout which limits natural ventilation; meaning more energy is used for mechanical ventilation. Cooling systems are then relied upon to maintain internal temperature during the hotter months. Buildings like these also tend to have high solar heat gains due to the large proportion of windows.

Opportunities for improvement

  • Use filtered fresh air from the outside as much as possible and replace older chillers with modern water-cooled chillers including heat recovery and free cooling.
  • Install PV systems on the south façade where there is the most sunlight.
  • Replace lighting with LEDs and modern controls, which help you to manage and monitor their use.
  • With electricity sub-metering more likely in modern high-rise building ensure you monitor half-hourly data to recognise peaks of energy consumption, this will help you identify where savings can be made.

More than one solution

As you can see there is no one solution for improving a building’s energy efficiency. Every building type will have different efficiency issues and will need to be assessed individually to find the most cost-effective solutions for improvement.

Some simple ways to start are by reducing your energy use through air conditioning by replacing it with natural or mechanical ventilation and the use of night and free cooling. Additionally, investing in LED lighting and looking to adopt readily accessible renewable solutions such as PV or ground cooling. Finally, accepting a wider range of temperatures in your buildings will really help to reduce your consumption, and bring down your costs.

If you would like to make energy efficiency improvements to your organisation’s property portfolio, TM44 inspections, or building surveys, our experienced energy consultants can carry out a comprehensive survey, provide valuable insights and propose a number of recommendations to suit your business. Interested? Contact us or call us now on 01908 690018.

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