Loft conversion starting out

Loft conversion starting out

Starting point with a loft conversion

As house prices are rocketing sky high for most people space in their home is an issue and on the other hand properties are not cheap in London. The most suitable option would be to convert your loft. A loft conversion is the most straightforward and quickest way of adding an extra bedroom and bathroom.

Is my loft suitable?

This is not straightforward to answer as every house varies in size. Below is a good guide In which you can check.

As most loft conversion are now under permitted development you will not need to go through the whole planning process stage which speeds up the process and cost.

Assessment: the first stage would be to get an architect or builder to measure it for you. The most important features that will determine whether your loft is suitable is the following:
1.The area you live in (whether there are any restriction)
2.Roof space
3.Head height
4. Roof pitch
If you house is pretty old chances are it will have a water tank in the loft. Although this is not a big issue your Gas Safe registered engineer will assist you further. If you need any help call us on 020 8904 3502

If your property or next door property has chimneys you would need to support your chimneys with gallow brackets. If your house is a semi-detached and your neighbour has removed their chimney you will need to support it with an RSJ steel. A structural engineer will make the calculation.

Head height is one of the most important factors there would be no point in converting a loft with a finished head height of 1.5 metres. In order to find the head height measure from the ridge timber to the top of ceiling joist. In leighman perspective measure from the highest point of the room to the bottom.

The usable part I.E where there is sufficient height should be 2.2 or higher. A loft conversion will typical use 7by2timber and therefore you would lose around 209mm from the top and as the loft floor is suspended you will lose 218mm once the finished floor is on. If the height of your loft is currently at 2.2m your finished loft height will be 1.77m

Staircase is another fundamental underlining factor. You will need to have a look on your first floor to see if you will be able to get a staircase to the loft. You will need clearance for your staircase to turn otherwise you may need to build a side dormer to allow for the staircase. If you live in a conservation area you will need to follow your specific councils design guide. If you need any advice call us today. If you’re not in a conversation area you may be able to builder a hip to gable with a dormer giving you sufficient height.

Next would be to asses the type structure. Majority of loft conversions would be a traditional frame type. A frame type is where the rafters and ceiling joists are put together with supporting timber to hold them in place. This is often the suitable type for conversion. The space can be opened and relatively inexpensive. The loft conversion will consist of rsj’s on the floor and a ridge beam going across. Their would be a load-bearing wall to support the ridge beam. Another way of you want to open the whole loft would be to erect rsj of the floor and up in the shape specified to your council. You will need to consult a structural engineer for steel calculation.

Type of Structure: Two main structures are used for roof construction — namely traditional framed type and truss section type. The traditional framed type is typically found in pre-1960s houses where the rafters and ceiling joists, together with supporting timbers, are cut to size on site and assembled. This type of structure has more structural input, so is often the most suitable type for conversion. The space can be easily, and relatively inexpensively, opened up by strengthening the rafters and adding supports as specified by a structural engineer.

My roof has less than 2.2m what do i do?

There are two option, solution 1 is to raise the roof. Depending on what area you’re in this may require planning permission. Raising the roof would involve removing part or potentially the whole of the existing roof. This could potentially be very costly as you may opt to get a covered scaffold structure to protect your house from any rain water while the roof is off.

Solution 2 this is only advisable if you high ceiling. You cut the joists down to give you more height in the loft. The finished height should be 2.3m minimum. In order to do this you will need to remove all the ceiling below the loft. You will need to use anchor bolts m12 with square washer for the new joists flooring. This job is not a DIY as you may be cutting timber that loading or supporting a specific object. Before trying this option measure the distance between the windows and the ceiling. If there is not enough height this will be a costly job to move all the windows down in order to get enough loft head height.


As stated above there will be steel roughly around 8inch in height. The existing joist will be unlikely to take a conversion floor there the floor is suspended with 7by2 timber floor slotted inside the steel. This may vary according to the structural engineer steel calculations but on average 8inch in height will be the norm. There will be a load bearing walls to hold in place the ridge beam. The load bearing walls are normally raised above the ceiling plaster work by using additional spacers below the joists ends. The spacers are critical and must be sufficient to stop the new floor joist deflection from touching the ceiling below. The new floor may run in the same direction as the old joist but this depends on your house and how the beams are sitting. Above the windows and door opening thicker joists will be used.

Can I have an open loft without any loading walls?

Yes you can however RSJ’s will need to be erected all around which is a more costly job. Get in touch with us now to discuss this further.