An Extension by Marble Construction.

By now the extension will be a watertight shell complete with windows, doors, interior walls and insulation but before the space can become habitable there are two remaining steps, the first fix and the second fix.

The first fix includes installation of all plumbing and electrical work which must be carried out before plastering and any other finishing work such as pipe and cable laying, heating installation and sanitation systems.

This work can be split into three main categories which are electrics, plumbing and heating.

Electrics Instillation

An electricians first job will be to install and fit all cables and boxes. Marble’s trained and fully qualified team of electricians will follow the customer’s exact specifications on where sockets and light fittings are required, as opposed to some companies which leave this down to the electrician to decide. This ensures sockets won’t be unreachable behind sofas, at the wrong end of the room for a customer’s TV or at the wrong height for the kitchen units.

A lack of power sockets is a common complaint amongst home owners. The rapid increase in consumer electronics from laptops to massage chairs has left a lot of previous builds inadequate for everyday life so the customer should be generous with the amount of power sources installed.

Electrical cables should run vertically or horizontally but always directly from the outlets to the junctions. This allows the homeowner and builders to avoid a nasty shock when drilling into a wall at a later date. Another damage when installing cables is structurally damaging the ceiling joists which they must be drilled through. to avoid damaging them:

  • Holes should be drilled at around the middle of a joist’s depth.
  • There should be no drilling within the first quarter of the joist’s distances from walls.
  • The size of the holes should be under a quarter of the depth of the joint.
  • Holes should not be drilled very close together.

It is important for the electrician to then calculate whether the existing consumer unit can cope with supplying to the original house and the extension. If not it might be a good excuse to replace an out-dated box anyway. Most new copper pipping installed will also need to be earthed to reduce the risk of the home owner receiving a shock if something goes wrong later.

Building Regulations will also insist that any new kitchen or bathroom requires a ventilation unit to prevent mold, damp and the other problems that usually ensue in an area filled with damp air. It is also necessary to install mains powered smoke alarms.

Once this is done, it is advisable for the customer to have one last check to make sure they have not missed anywhere where they need a socket, a light switch or a light fitting as any additions after plastering will increase time and cost to the customer.

A Kitchen Instillation by Marble.

Certain types of lighting are widely documented to effect the mood of those exposed to them, for this and other reasons, many people having their homes extended choose other types of lighting than a dangling bulb in the middle of the room.

There are thousands of different options such as wall lights, floor up lights, Neon tubing, LED strips and lights built into worktops and surfaces. The most important point is to choose a style in keeping with the original property, chrome wall lights are not going to look above a Georgian oak fireplace.



Most extensions will contain a bathroom, toilet or kitchen. If they do it will be necessary to extend the cold water supply. Even if there is no need for this, additional heating and radiators will still be required. The same rules for fitting cables into walls and ceilings applies to fitting pipes for heating.

Each water and waste source brings up it’s own problems. Toilets if on the opposite side of the property to the drains are likely to require a a macerator to allow the waste to flow through normal gauge pipping. However as these require electrical power, they are useless in a power cut. All properties are also required to have at least one toilet which does not rely on a macerator.

With showers and bath taps, the need for a high pressure, consistent, hot and cold water supply is suited to modern mains hot water systems. Showers also require thermostatic controls so use of water in other parts of the house does not give the unsuspecting shower user a scalding surprise. Shower trays are also notorious for leaking and mold, it is always advisable to use marine plywood bases for tiling rather than plasterboard. To reduce the risk of leaks, use an all-in one shower unit or a stone-cast tray as opposed to acrylic or steel.



With radiators, it is important to specify exactly where radiators are needed so that they will not obstruct the customer’s furniture or kitchen unit fitting. That said there are a wide range of sizes and shapes to help fit any space.

With hot water there are two options. The first and most traditional is a boiler in an airing cupboard, the boiler is fed from the cold water tank in the loft and heated by central heating copper pipes going in and out of the boiler. This is called an indirect system. The second type of hot water providing is becoming more and more poular with over 50% of new housing using this system. These systems do not require storage tanks in the loft space. In this system incoming cold water is either directly heated by an electric heater or from a central heating boiler. This hot water is stored in the vessel and is forced out by incoming cold mains water in the vessel when the tap is turned in the bath or sink.

For heating systems, adding new radiators might over work an existing boiler’s capacity or just be too much stress for an older model. Most boilers will last no longer than twenty years and many will last much less. Building regulations now require that all boilers fitted are condensing boilers as they are much more energy efficient. One type of condensing boiler to consider is a combination boiler which provide hot water for taps as well as the central heating system. Although combination boilers are more expensive and bulky, the cost of fitting them compared to installing a heating and a boiler system is a lot less. The main downside is their slower flow rates for taps.

Underfloor Heating Installation
The Installation of underfloor heating by Marble Construction.

A type of heating that is making a comeback is underfloor heating. After being the heating of choice in Roman villas, more refined and efficient systems are now in place, with all the grandeur of not needing slippers to walk around in the mornings! The two types are wet systems which pump water through pipes installed into the floor screed and dry systems which use very thin mats of heating elements which are laid directly under floor coverings like tiles or carpet.

For extensions wet systems are favored as it is easy to install them during the construction process compared to in existing properties where dry systems are cheaper to install. Under floor heating is very efficient compared to radiators so over time will negate their higher instillation cost.


Go Green and Help the Planet (and Your Wallet)

There are loads of grants available for those wishing to install solar panels or wind turbines. It is also possible to sell energy back to the provider if there is any excess after the customer’s consumption of energy. There are solar systems for heating water as opposed to a boiler for in the summer and solar panels for generating electricity all year round. With utility bills increasing and the cost of solar systems decreasing, renewable energy is becoming a serious threat for utility providers.

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