Heating duct in the floor at Watts Gallery, Surrey

Heating duct in the floor at Watts Gallery, Surrey © Historic England Archive
Heating duct in the floor at Watts Gallery, Surrey © Historic England Archive

Condition Surveys and Investigations

When replacing or installing new building services, or planning a maintenance programme, the first step is a thorough survey of the existing services.

The survey should include the assessment of the size, capacity and present loadings of the existing utility incoming services, as well as existing heating boilers, cooling plant, ventilation fans, air handling, electrical panels and switchgear and equipment.

Survey work should be non-destructive and not involve any cutting, removal of building fabric or finishes, lifting of floors, coverings or on-site digging. If such intervention is needed, you will need the prior approval of the building owner.

Building performance and energy efficiency

If a building is already in use, a survey is also an opportunity to review how the building currently performs and its energy efficiency. For example, are some parts of the building colder or warmer than others? This might indicate that some repairs or improvements to the heating system are needed.

Our energy efficiency guidance looks at reducing carbon emissions and fuel bills, improving comfort levels, and compliance with statutory requirements such as Part L of the Building Regulations or the Private Rented Sector Regulations. The suite of guidance includes:

Historic interest

A survey will help reveal the history of how the building worked in the past. The existing services may be of historic interest and may even be included in the listing schedule for the building; or you may uncover a piece of engineering heritage that deserves to be reused or recorded. Recording and conserving historic building services explains more.

Detail of the servant bell buzzers in the VIP accommodation at Corsham Tunnels, Wiltshire
Detail of the servant bell buzzers in the VIP accommodation at Corsham Tunnels, Wiltshire © Historic England Archive

Hazardous substances

When carrying out a survey, you need to be aware that there may be hidden dangers as a result of toxic or hazardous materials that were used in the past which have now been banned. Examples include asbestos, which can be found in insulation materials, and lead-based pipe work or old oil in electrical switchgear. You should always follow Health and Safety Executive’s guidance about hazardous substances.

Assessing existing services and their condition

Building services engineering survey consists of two parts – the desk top study and the site survey. It's useful to carry out the desk based study before visiting the site.

The information from the desk based study needs to be verified in the on-site survey. Together, the desk based study and site survey will help you review what services and routes exist against what is required.

The desk based study involves:

  • Researching the buildings history and significance. The National Heritage List for England (NHLE) includes all nationally protected historic buildings and sites in England. Books or visitor guides may also be useful
  • Looking for any services record drawings. These may be kept in operation and maintenance manuals or an archive
  • Looking for testing and inspection reports such as electrical, gas and mechanical systems reports
  • Collating information on incoming supplies and electricity, gas and water usage
  • Checking the asbestos register for the property
  • Collating any environmental monitoring data such as temperature and humidity records, which if you have a Building Management System (BMS) you could find there
  • There may be asset registers which are lists of all the services in the building used by maintenance staff

The site survey involves:

  • Assessing the condition of the systems and components
  • Checking if what is on the record drawings is correct. The drawings could be very old and out of date and not show subsequent services installed
  • Assessing if any services can be retained and reused
  • Assessing the heritage significance of the systems
  • Reviewing the capacity of the current systems
  • Accessing issues for maintenance, replacement or new work
  • Identifying maintenance issues
  • Identifying hazards
  • Carrying out building performance inspections such as thermal imaging, load monitoring
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