Installing New Services
In older buildings it's important that the lighting, power and heating systems remain safe, efficient and suit the current use.
When building uses change, or services come to the end of their life, they will need to be replaced. The removal and replacement must be done in a way that limits damage to the historic fabric of the building.
Modern building services comprise a much wider range of services than in the past. They include mechanical, electrical and plumbing or public health engineering (sometimes referred to as MEP):
- Communication lines, telephones and IT networks (ICT)
- Gas, electricity, water
- Heating, ventilation and air conditioning (HVAC)
- Lightning and surge protection
- Electrical power systems, distribution boards and switchgear
- Internal and external lighting, including emergency lighting
- Hot and cold water systems
- Drainage, plumbing, and sewers
- Escalators and lifts
- Fire detection and protection
- Security and alarm systems
- Renewable or low carbon technology installations such as solar arrays
Conservation principles and reversibility
The design and installation of building services systems in historic buildings needs to be considered carefully. The historic interest of a building can be undermined by successive installations. Work should aim to protect the building and its setting with no loss of historic fabric, and follow the principle of reversibility.
The installation work should not only include a plan on how it is to be installed, but how it will be removed at the end of its useful life. This approach helps to minimise damage to historic fabric. Reversibility requires much more planning at the design stage. You need to consider and detail every hole and fixing. You need to adopt different standards such as fixing into mortar joints, which can be repaired by repointing, rather than into masonry which cannot be so readily repaired. The very size of heating and ventilation ducts may make it difficult to comply with the reversibility principle.
Historic England’s Conservation Principles provides further general guidance.
While the final appearance of the installations is important, it doesn't necessarily have to be designed to look historic. After all, modern services are relatively new as they have only been around for 150 years. Trying to produce a period look to installations may be inappropriate. Why install Victorian style radiators in a Norman church or Tudor house? Well-designed contemporary and innovative installations may be a better solution.
In all cases the design, layout and installation of the building services should respect historic buildings and their settings. It's becoming much easier to successfully integrate services into the building so as to be almost unnoticeable. For example, aspirated fire-detection systems can be installed which do not require detectors being fixed to ceilings. Lighting can be incorporated into or on top of picture rails or fixed furniture, and it can provide not only the normal lighting function but emergency lighting as well. Radio-based CCTV, detection, alarm and control systems can now eliminate the need for extensive cabling.
Designing and building
Before any work starts, carry out a thorough and systematic investigation through both desk-top and on-site surveys. This'll provide a clear and co-ordinated picture of what services and routes exist against what's required. Then determine the extent of invasive work by judging the value of the improvement in building services to be gained, against the damage and disturbance to historic fabric.
The design of new building services within historic buildings should take advantage of any existing openings and services routes that already exist. If new openings are necessary, the designer should ensure that as many services as possible share a common route through the building. This will minimise the loss of historic fabric and along with designing in spare capacity will ensure, at least in the short term, that further loss of building fabric is contained.
Where the building design lends itself to offering suitable routes, a surface installation may sometimes be a better solution. For example mouldings, column capitals, cornices, or balustrades may disguise the presence of a carefully installed cable or pipe. However it's important to ensure that an installation of this type does not cover up, damage or interrupt the view of important building features and surfaces; or create any dirt traps or staining patterns from heat and air movement.
You must agree the routes and the methods of fixing with the property owner. You may also need statutory consents for a listed building or scheduled monument. The building services consultant/designer should record the agreed routes and fixing methods on the design and working drawings and where relevant the Building Information Model (BIM). They must also ensure that the installation is carried out in accordance with these drawings.
Please click on the gallery images to enlarge.
When installing new services like gas, electricity and water give careful consideration to known or suspected buried archaeology. An archaeologist may need to be in attendance during the excavation works. A Written Scheme of Investigation (WSI) may be needed which will set out the archaeological recording work. Allow time to liaise with the archaeologist during the excavation works.