Reducing heat loss in the home

insulation

Many houses fall well below the minimum thermal insulation standards set under building regulations. Although some forms of insulation should be carried out by a professional, there is still much that can be done by the home handyman. Before you begin the process of keeping heat inside where it belongs, it is useful to understand the ways in which heat is lost from a house. The amount of heat lost does depend on the nature of the building, its aspect and exposure to winds – and figures vary from house to house.

In a typical uninsulated house approximately one quarter is lost through the roof, one-third through the walls, one-tenth through the doors, one-fifth through the windows and one-sixth through the floors. After insulation these losses can be cut down to approximately one-twentieth, one-tenth, one-twentieth, one-ninth and one-tenth respectively. So although insulation does not prevent all the heat escaping, it substantially reduces the amount of loss and correspondingly diminishes the size of your heating bills.

It shortens the time it takes to heat a room and enables you to keep down the number and size of radiators and the size of the boiler or to install a less powerful and therefore less expensive central heating system around the home. Forms of insulation vary from the simple rubber strip draught excluder on your door to insulating boards lining the walls. What you decide to do will depend on the amount of time and money you have available; but the more thoroughly you carry out the job, the greater the rewards will be in terms of comfort and eventual savings, which will well repay the initial expense and effort.

Insulating the loft space

Heating costs rise with the warm air if heat is allowed to escape through the roof. By insulating the loft area you can keep down the bills and hold heat where it belongs – in the house. A loft that is not insulated accounts for a heat loss of about 25 percent in the average size house. Several forms of insulation are available and fall into two categories: loose-fill materials such as velmiculite granules and the mat type made from glass fibre or mineral wool. The materials we mention are all resistant to fire and you must check on the fire-resistance of any alternative product you consider buying. As a precaution,first treat all timber for woodworm.

Insulation slab loft conversion
Insulation slab
A versatile thermal and acoustic rock mineral wool insulation slab suitable for a wide variety of applications such as drylining, stud partitions, loft conversions, etc

Granule insulation
One advantage of using granules to insulate your loft is that they flow easily and smoothly and will fill any awkward spaces. They are also safe to handle since they do not contain any splinters or loose fibres.

Vermiculite
Expanded mica in granule form. this is supplied in easy-to-handle bags. The manufacturer’s instructions will give you a guide to the number of bags needed for specific areas. You should wear a mask and some form of eye protection when using vermiculite since it is a dusty material that easily gets into the atmosphere.

Laying granules
Pour vermiculite between the joists to a depth of about l00mm, which will bring it almost to the level of the joists. Level the granules to the required depth by dragging a T shaped piece of timber along the top of the joists. This can be made from any piece of scrap wood at least 150mm wide and 500mm long. You must cut the base of the ‘T’ to fit the gaps between the joists. Use a broom or rake for awkward corners.

Mat insulation
This form of insulation does not need to be laid as thickly as granules and should be used in lofts where there are gaps around the eaves, since wind might blow the granules about.

Glass fibre
The most economical form of mat insulation for loft spaces. It comes in thick rolls and is available in 400mm widths, equivalent to the space between roof joist in most houses, and can be cut quite easily with a large pair of scissors or a sharp knife. Even handled carefully, glass fibre can irritate the skin, so always wear gloves when working with it.

Mineral wool
Another mat type’ this is made from rock fibre and is handled in the same way as glass fibre.

Laying rolls
Place the roll of material between the joists and tuck the end under the eaves. Working backwards, unroll the material until you reach the other end of the roof. Cut it and tuck the end under the eaves as before. Lay the strip flat between the joists or, if it is a little wider, turn the sides up against the sides of the joists. Continue in this way until the whole loft area has been covered. If you have to join two strips in the middle of the roof butt them together.

Insulating awkward areas
You will find it easier to cover awkwardly shaped or inaccessible areas with granules. A l00mm thickness of granules is equivalent to 80mm of blanket materials in terms of effective insulation. Whichever method of insulation you use, don’t insulate under the cold water tank. You must allow a warm air current to flow from below to prevent the tank from freezing in cold weather. But don’t forget to insulate the loft flap or cover. Cut a piece of mat material to the size of the cover and stick it down with a latex adhesive. And when working in the loft, remember to tread only on the joists or on a board placed across them.

Other forms of insulation
Even more insulation can be provided if you make a floor to the loft by fixing panels of chipboard or planks of timber to the joists above the insulating material. This will also give you extra storage space, but you may have to strengthen the joists by spanning the load-bearing walls with large timbers before laying the floor if you want to put heavy items on it. Seek advice from a builder or your local authority. Heat loss through the roof space can be further reduced by lining the ceilings immediately below the loft with an insulating-type material such as expanded polystyrene or acoustic tiles. It should be emphasized, however, that this is not a substitute for loft insulation. Effective insulation of the floor will make the loft colder, so it is vitally important to ensure the cold water tank (except beneath it) and all pipes are thoroughly protected, otherwise they will be susceptible to frost damage.

Protection from frost
The type of loft most likely to suffer from frost damage is one with an unboarded tile-hung roof. If your roof has no close-boarding or roofing felt as is the case with many older houses – it is worth insulating it. Cut lengths of roofing felt about 200mm wider than the distance between the rafters. Lay one long edge onto the inside edge of one rafter, lay a 25 x 15mm batten onto the felt and screw through the batten and felt into the rafter. Use No 8 countersunk screws 25mm long spacing them at 300 380mm intervals. Don’t use nails as the vibration from hammering could dislodge and break the roof tiles. Stretch the roof felt across to the next rafter and fix the other edge onto the edge of that rafter, again screwing through a batten. Leave a space between the roof and the felt to allow air to circulate, otherwise you may find rot will form on the rafters. An alternative to roofing felt is tempered hardboard: butt-joint each panel of hardboard to the next by screwing it to the centre of each rafter with No 8 countersunk screws 25mm long. You may have to trim your cut panels so they fit neatly in the middle of each rafter. All this work can be done in easy stages; when you have finished, the roof space will certainly remain warmer in winter and will also be much cleaner – an important consideration if you are using the loft for storage.

Extensions ideas

Extensions – London

If you are looking for a London Building Company to build your extension,contact us.
open plan ground floor extension
House Extension
House Extension

Rear one storey extension
Rear one storey extension

Rear Extension Lead Roof
Rear Extension Lead Roof

Rear Kitchen Extension Flat Roof
Rear Kitchen Extension Flat Roof

Kitchen Extension Pitched Roof
Kitchen Extension Pitched Roof

One storey house extension
One storey house extension

2 Storey Home Extension
2 Storey Home Extension

Kitchen Extension Flat Roof
Kitchen Extension Flat Roof

House extension flat roof terrace
terrace extension balcony
House extension flat roof terrace

Kitchen Extension
Kitchen Extension 1 storey
Kitchen Extension 1 storey

Rear Kitchen Extension
Rear Kitchen Extension

Side two storey House Extension
Side two storey House Extension

Rear extension 2 storey
Rear extension 2 storey

Side return Extension
side return extension
Side return Extension

Side Extension
Side Extension

Side return 2 storey Extension
Side return 2 storey Extension

Side extension Conservation area
Side extension Conservation area

L shaped 1 storey side & kitchen extension
L shaped 1 storey, side & kitchen extension

L shaped 1 storey, side & kitchen extension - Interior view , open plan floor
L shaped 1 storey, side & kitchen extension – Interior view , open plan floor

L shaped 2 storey extension - Front view

L shaped 2 storey extension

 L shaped 2 storey house extensions
L shaped 2 storey house extensions

Interior - Open plan L shaped extension
Interior – Open plan L shaped extension

Two storey side and rear extension
Two storey side and rear extension

Two storey side and rear extension
Two storey side and rear extension

Kitchen Extension
Kitchen Extension

Interior Kitchen Extension - Open plan floor
Interior Kitchen Extension – Open plan floor

Side rear extension
Side rear extension

Side return extension
Side return extension

Rear Side 2 storey extension
Rear & Side 2 storey extension

Kitchen rear home extension

Planning Permission

This guidance reflects increases to the size limits for single-storey rear extensions which apply between 30 May 2013 and 30 May 2016, and the associated neighbour consultation scheme.

An extension or addition to your house is considered to be permitted development, not requiring an application for planning permission, subject to the following limits and conditions:

No more than half the area of land around the “original house”* would be covered by additions or other buildings.
No extension forward of the principal elevation or side elevation fronting a highway.
No extension to be higher than the highest part of the roof.
Single-storey rear extension must not extend beyond the rear wall of the original house* by more than three metres if an attached house or by four metres if a detached house.
In addition, outside Article 1(5) designated land* and Sites of Special Scientific Interest the limit is increased to 6m if an attached house and 8m if a detached house until 30 May 2016.
These increased limits (between 3m and 6m and between 4m and 8m respectively) are subject to the neighbour consultation scheme.
Maximum height of a single-storey rear extension of four metres.
Extensions of more than one storey must not extend beyond the rear wall of the original house* by more than three metres.
Maximum eaves height of an extension within two metres of the boundary of three metres.
Maximum eaves and ridge height of extension no higher than existing house.
Side extensions to be single storey with maximum height of four metres and width no more than half that of the original house.
Two-storey extensions no closer than seven metres to rear boundary.
Roof pitch of extensions higher than one storey to match existing house.
Materials to be similar in appearance to the existing house.
No verandas, balconies or raised platforms.
Upper-floor, side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
On designated land* no permitted development for rear extensions of more than one storey.
On designated land no cladding of the exterior.
On designated land no side extensions.

Planning Permission for Extensions